Appendix A

Final Draft Update of Item P-304

Cement-Treated base Course

# DESCRIPTION

304-1.1 This item shall consist of a cement-treated base (CTB) course
composed of mineral aggregate and cement, uniformly blended and mixed
with water. The mixed material shall be spread and shaped with a
mechanical spreader, and compacted with rollers in accordance with these
specifications and in conformance to the lines, grades, dimensions, and
cross-sections shown on the plans.

# MATERIALS

304-2.1 AGGREGATE. The aggregate shall be select granular materials,
comprised of crushed or uncrushed gravel and/or stone, or recycled
crushed and graded portland cement concrete (PCC). The material shall be
free of roots, sod, and weeds. The crushed or uncrushed aggregate shall
consist of hard, durable particles of accepted quality, free from an
excess of soft, flat, elongated, or disintegrated pieces, and
objectionable matter. The method used in producing the aggregate shall
be such that the finished product is as consistent as practicable. All
stones and rocks of inferior quality shall be wasted. When recycled PCC
is used as the aggregate, it must meet the requirements for virgin
aggregate.

The percentage of wear of the crushed aggregate retained on the No. 4
(4.75-mm) sieve shall not be greater than 40 percent when tested in
accordance with ASTM C 131. The sodium sulfate soundness loss shall not
exceed 10 percent, or the magnesium sulfate soundness loss shall not
exceed 13 percent, after five cycles, when tested in accordance with
ASTM C 88.

When tested in accordance with ASTM C 136, the aggregate shall conform
to the gradations shown in Table 1. An aggregate blend that meets the
requirements of Table 1 shall be selected by the Contractor and used in
the final mix design. The final aggregate blend shall be well graded
from coarse to fine within the limits designated in the table and shall
not vary from the low limit on one sieve to the high limit on adjacent
sieves, or vice versa. The portion of final aggregate blend passing the
No. 40 (425-µm) sieve shall have a liquid limit of not more than 25 and
a plasticity index of not more than 6 when tested in accordance with
ASTM D 4318.

Table 1. Aggregate gradation for CTB material.

  -------------------- ------------------------ --------------------------
  **Sieve Size**       **Percentage by Weight   
                       Passing Sieves**         

                       **Gradation A**          **Gradation B**

  2 in (51 mm)         100 ^1^                  100 ^1^

  No. 4 (4.75 mm)      45 - 100                 55 - 100

  No. 10 (1.80 mm)     37 - 80                  45 - 100

  No. 40 (450 μm)      15 - 50                  25 - 80

  No. 80 (210 μm)      0 - 25                   10 - 35
  -------------------- ------------------------ --------------------------

^1^ Maximum size of aggregate is 1 in (25.4 mm) when used as a base

course under Item P-501, Portland Cement Concrete Pavement.

If recycled PCC does not meet the requirements of virgin aggregate, the
Engineer should evaluate the test parameters for recycled aggregate.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer shall refer to the new specification on recycled PCC
> aggregate for additional guidance.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

All aggregate samples required for testing shall be furnished by the
Contractor at the expense of the Contractor. Sampling shall be performed
by the Contractor in accordance with ASTM D 75.

*304-2.1.1 Reactivity.* Virgin crushed material (stone or gravel) or
crushed and graded recycled PCC materials to be used in CTB shall be
evaluated and tested by the Contractor for alkali-aggregate reactivity
in accordance with ASTM C 1260. The test results shall have a measured
expansion equal to or less than 0.10 percent in 16 days. The laboratory
conducting the tests shall meet requirements of ASTM C 3666. Bank run
gravel material is excluded from this requirement.

304-2.2 CEMENT. Cement shall conform to the requirements of ASTM \[ \].

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer shall specify ASTM C 150 Type I, II, III, IV, or V or
> ASTM C 595 Type IS, IS-A, IP, IP-A, P, or PA. Type II cement shall be
> specified in areas with a history of sulfate reaction with the
> selected aggregate.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

304-2.3 CEMENTITIOUS ADDITIVIES. Pozzolanic and ground granulated blast
furnace (GGBF) slag may be added to the CTB mix. If used, each material
must meet the following requirements:

a.  Pozzolan. Pozzolanic materials must meet the requirements of ASTM C
    618, Class C, F, or N with the exception of loss of ignition, where
    the maximum shall be less than 6 percent for Class F or N. \[The
    supplementary optional chemical and physical properties of tables 1A
    and 2A contained in ASTM C 618 shall apply\].

b.  GGBF Slag. Slag shall conform to ASTM C 989, Grade 80, 100, or 120.

304-2.4 WATER. Water used in mixing or curing shall be clean and free of
oil, salt, acid, alkali, sugar, vegetable, or other deleterious
substances injurious to the finished product. Water shall be tested in
accordance with the requirements of AASHTO T 26. Water known to be of
potable quality may be used without testing.

304-2.5 CURING MATERIALS. Curing materials shall conform to the
requirements provided below, as defined by the type of pavement surface
to be placed on top of the CTB layer.

*304-2.5.1 Portland Cement Concrete (PCC) Pavement*. For curing CTB
placed under PCC pavement, use white-pigmented, liquid membrane-forming
compound conforming to ASTM C 309, Type 2, Class A or Class B
(wax-based).

*304-2.5.2 Hot Mix Asphalt (HMA) Pavement*. For curing CTB placed under
HMA pavement, use emulsified asphalt conforming to ASTM C 977 or ASTM D
2397 (Table 2).

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> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> If emulsified asphalt is allowed as a curing agent, the Engineer shall
> specify
>
> the type and grade of material to be used and the corresponding
> application temperature from Table 2.

Table 2. Emulsified asphalt curing material.

  ------------------ ------------------- ------------------- -----------------
  **Type and Grade** **Specification**   **Application       
                                         Temperature**       

                                         **°F**              **°C**

  Emulsified Asphalt                                         

  RS-1, SS-1         ASTM D 977          75 - 130            25 - 55

  CRS-1              ASTM D 2397         75 - 130            25 - 55
  ------------------ ------------------- ------------------- -----------------

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> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

304-2.6 SAND BLOTTER. If emulsified asphalt is used as a curing
material, sand shall be applied, when required, for the prevention of
pick-up of emulsion curing materials. The sand material shall be clean,
dry, and non-plastic.

304-2.7 CHOKE STONE. Choke stone shall be used as a bond-breaker between
the CTB and PCC surface. It shall conform to the requirements of the new
FAA specification for choke stone.

# composition of Mixture

304-3.1 GENERAL. The CTB material shall be composed of a mixture of
aggregate, \[Portland cement\] \[blended hydraulic cement\], and water.
Fly Ash or GGBF slag may be used as a partial replacement for Portland
cement.

304-3.2 MIX DESIGN. The mix design shall utilize a cement content that,
when tested in the laboratory according to ASTM D 1633, produces a 7-day
compressive strength meeting the following requirements:

a.  For CTB placed under PCC pavement: 500 psi (3,447 kPa) minimum and
    1,000 psi (6,895 kPa) maximum.

b.  For CTB placed under HMA pavement: 750 psi (5,170 kPa) minimum and
    1,000 psi (6,895 kPa) maximum.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> In areas subject to considerable wet-dry and/or freeze-thaw cycles,
> insert the following statement:
>
> "Wet-dry and/or freeze-thaw tests shall be performed in accordance
> with ASTM D 559 and D 560, respectively. The weight loss for each type
> of test shall not exceed 14 percent after 12 cycles. However, if a
> 7-day compressive strength of 750 psi (5,170 kPa) is achieved, the
> wet-dry and freeze-thaw tests are not necessary."
>
> An estimated cement content may be determined from Table 1, Chapter 2,
> of the Soil-Cement Laboratory Handbook, published by the Portland
> Cement Association (PCA). In designing the mixture, cement contents
> above and below the initial estimated amount should be tested to
> determine the minimum quantity of cement needed to achieve the
> required strength (or strength and durability where freeze-thaw
> resistance is deemed necessary by the Engineer).
>
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> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

If the minimum compressive strength value is not achieved within the
specified time, the material will not be subject to removal, but further
construction and other traffic shall only be allowed on the surface when
the strength is 350 psi (2,413 kPa). Laboratory tests can be used to
determine when the strength is obtained.

The mix design shall include a complete list of materials, including
type, brand, source, and amount of cement, fine aggregate, coarse
aggregate, water, and cementitious additives, if used. It shall also
contain the 7-day compressive strength test results and the results of
the wet-dry and/or freeze-thaw tests.

Should a change be made in aggregate sources or type of cement, or if
cementitious additives are added or deleted from the mix, production of
the CTB mix shall be stopped and a new mix design shall be submitted.

304-3.3 SUBMITTALS. At least \[ \] days prior to the placement of the
CTB, the Contractor shall submit certified test reports to the Engineer
for those materials proposed for use during construction, as well as the
mix design information for the CTB material. Tests older than 6 months
shall not be used. The certification shall show the ASTM or AASHTO
specifications or tests for the material, the name of the company
performing the tests, the date of the tests, the test results, and a
statement that the material did or did not comply with the applicable
specifications. The submittal package shall include the following:

a.  Sources of materials, including aggregate, cement, cementitious
    additives, curing, and bond-breaking materials.

b.  Physical properties of the aggregates, cement, cementitious
    additives, curing, and bond-breaking materials.

c.  Mix design

    -   mix identification number.

    -   aggregate gradation.

    -   cement content.

    -   water content.

    -   cementitious materials content.

> d\. Laboratory test results

-   compaction and strength testing procedures.

-   laboratory compaction characteristics (maximum dry density and
    optimum moisture content).

-   compressive strength at 7 days.

-   Wet-dry and/or freeze-thaw weight loss, if applicable.

No CTB material shall be placed until the submittal is accepted in
writing by the Engineer.

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> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Insert the appropriate number of days for Contractor submittal of
> certified test reports for the proposed materials; 10 to 20 days is
> typical.
>
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> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

# EQUIPMENT

All equipment necessary to mix, transport, place, compact, and finish
the CTB material shall be furnished by the Contractor. The equipment
shall be inspected and approved by the Engineer at the job site prior to
the start of construction operations.

304-4.1 MIXING. The mixer shall be a batch or continuous-flow type
stationary mixer and shall be equipped with calibrated metering and
feeding devices that introduce the aggregate, cement, water, and
cementitious additives (if used) into the mixer in the specified
quantities. If necessary, a screening device shall be used to remove
oversized material greater than 2 in (51 mm) from the raw aggregate feed
prior to mixing.

Free access to the plant must be provided at all times for inspection of
the plant's equipment and operation and for sampling the CTB mixture and
its components, as deemed necessary by the Engineer.

304-4.2 HAULING. The mixed CTB material shall be transported from the
plant to the job site in trucks or other hauling equipment having beds
that are smooth, clean, and tight. Truck bed covers shall be provided
and used to protect the CTB from rain. CTB material that becomes wet
during transport shall be subject to rejection.

304-4.3 PLACING. CTB material shall be placed using a mechanical
spreader or a machine capable of receiving, spreading, and shaping the
mixture without segregation into a uniform layer or lift. The equipment
shall be equipped with a strike-off plate capable of being adjusted to
the specified layer thickness. It shall also be equipped with two end
gates or cut off plates, so that the CTB may be spread in widths varying
up to lane width.

304-4.4 COMPACTION. Compaction of the CTB layer shall be accomplished
using one or a combination of the following pieces of equipment:

-   Tamping or grid roller.

-   Steel-wheeled roller

-   Vibratory roller.

-   Pneumatic-tire roller.

-   Vibrating plate compactor (for areas inaccessible to rollers).

The number, type, and weight of rollers and/or compactors shall be
sufficient to compact the mixture to the required density.

304-4.5 FINISHING. Final trimming of the compacted CTB to meet surface
requirements shall be accomplished using a self-propelled grader or
trimming machine, with a mold board cutting edge, which is at least 12
ft (3.7 m) wide and is automatically controlled by sensors in
conjunction with an independent grade control from a taut stringline.
Stringline will be required on both sides of the sensor controls for the
pilot lane. For all other lanes, a single stringline on the outside and
grade matching with previously completed adjacent lanes is permissible.

# 

# CONSTRUCTION METHODs

304-5.1 WEATHER LIMITATIONS.

*304-5.1.1 Cold Weather.* The CTB material shall not be mixed or placed
while the air temperature is below 40°F (4°C) or when conditions
indicate that the temperature may fall below 35°F (2°C) within 24 hours.
The CTB shall not be placed on frozen surfaces.

*304-5.1.1 Rain.* The CTB may not be placed when rainfall is occurring.
If an unexpected rain event occurs during placement, the layer should be
quickly compacted. CTB material that becomes wet by rain during
transport or placement shall be evaluated by the Engineer, and may be
subject to rejection.

304-5.2 PREPARATION OF UNDERLYING COURSE. The underlying course shall be
checked by the Engineer before placing and spreading operations are
started, in order to ensure that it is free of any ruts, depressions, or
bumps and is finished to the correct grade. Any ruts or soft yielding
places caused by improper drainage conditions, hauling, or any other
cause, shall be corrected before the CTB mixture is placed thereon. The
underlying course shall be wetted in advance of placing the CTB layer.
The final prepared grade prior to placing the CTB should be in a firm
and moist condition free of frost. Use of chemicals to eliminate frost
will not be permitted.

To ensure proper drainage, placement of the base shall begin along the
centerline of the pavement on a crowned section or on the highest
elevation contour of a pavement with variable cross slope.

304-5.3 GRADE CONTROL. Grade control between the edges of the CTB shall
be accomplished by grade stakes, steel pins, or forms placed in lanes
parallel to the centerline and at intervals of 50 ft (15.2 m) or less on
the longitudinal grade and at 25 ft (7.6 m) or less on the transverse
grade.

304-5.4 HANDLING, MEASURING, AND BATCHING. The continuous flow central
plant site, layout, equipment, and provisions for transporting material
shall assure a

continuous supply of material to the work. Aggregate stockpiles shall be
constructed in a manner that prevents segregation and intermixing of
deleterious materials.

Aggregates that are segregated or mixed with earth or foreign material
will not be accepted.

Continuous flow plants shall be equipped with feeders to proportion
aggregates and bulk cement, by weight, automatically and accurately.
When bulk cement is used, the Contractor shall use a suitable method of
handling the cement from weighing hopper to transporting container or
into the batch itself for transportation to the mixer, such as a chute,
boot or other device, to prevent loss of cement. The device shall be
arranged to provide positive assurance that the cement content specified
is present in each batch.

304-5.5 MIXING. Aggregate and cement may be proportioned either by
weight or volume, and shall be mixed sufficiently to prevent the forming
of cement balls when water is added. The mixing time shall be that which
is required to secure an intimate, uniform mixture of aggregate, cement,
water, and pozzolan (if used). The minimum mixing time will be based on
the uniformity and consistency of the mixture.

304-5.6 PLACING. The CTB mixture shall be deposited on the moistened
subgrade or subbase and spread into a uniform layer of such width and
thickness that, following compaction and trimming, conforms to the
required grade and cross-section. The Contractor may install the CTB
layer in single or multiple compacted lifts; however, each compacted
lift must be at least 4 in (102 mm) thick and no greater than 6 in (152
mm) thick. In multi-lift construction, the surface of the compacted lift
shall be kept moist until covered with the next lift. Successive lifts
shall be placed and compacted so that the required total depth of the
CTB layer is completed within 12 hours.

A single spreader may be used, provided it is capable of placing a
uniform, full-depth layer of material across the full width of the base
in one pass. Otherwise, two or more spreaders will be required, and
shall be operated so that spreading progresses along the full width of
the base in a uniform manner.

304-5.7 COMPACTION. Immediately upon completion of the spreading
operations, the CTB material shall be thoroughly compacted using
approved compaction equipment. At the start of compaction, the moisture
content shall be within 2 percentage points of the specified optimum
moisture.

304-5.8 FINISHING. Upon completion of compaction, the surface of the CTB
layer shall be shaped to the specified lines, grades, and cross-section.
During the finishing process, the surface shall be kept moist by means
of fog-type sprayers. Compaction and finishing shall be done in such a
manner as to produce a smooth, dense surface, free of ruts, cracks,
ridges, and loose material. All placement, compaction, and finishing
operations shall be completed within 2 hours from the start of mixing.
Material not completed within the 2-hour time limit shall be removed and
replaced at the Contractor's expense.

CTB layer limits that extend beyond the edges of the new PCC surface
course shall be rolled down or shaped in such a manner that the drainage
is away from the new PCC surface course edge.

304-5.9 CONSTRUCTION JOINTS. At the end of each day\'s construction, a
transverse construction joint shall be formed that is a true vertical
face (perpendicular to the centerline) and is free of loose material.

Longitudinal construction joints (parallel to the centerline) shall be
formed to a consistent, well-defined near vertical edge that is free of
loose material. The longitudinal joints shall be located such that there
is a 2-ft (0.6-m) minimum offset from planned joints in any overlying
layer.

While forming construction joints, the Contractor shall make sure the
material in the joint area is adequately compacted and that the joints
are finished level and even with the remainder of the CTB layer.

304-5.10 CURING. The compacted and finished CTB shall be cured with the
approved curing agents as soon as possible, and in no case later than 2
hours after completion of the finishing operations. The layer shall be
kept moist using a moisture-retaining cover or a light application of
water until the curing material is applied.

When asphalt emulsion is used as the curing agent, the entire surface of
the CTB layer shall be uniformly sprayed with the emulsion at a rate of
between 0.15 and 0.30 gal/yd^2^ (0.7 and 1.4 L/m^2^); the exact
temperature and rate of application being that required to achieve
complete and uniform coverage without runoff. Should it be necessary for
construction equipment or other traffic to use the asphalt-covered
surface, sufficient sand blotter cover shall be applied to prevent
pick-up.

When liquid membrane-forming curing compound is used as the curing
agent, the entire surface of the CTB layer shall be uniformly sprayed
with the compound at the rate of 1 gal (3.8 L) to not more than 200
ft^2^ (18.6 m^2^). The rate of application shall be determined such that
a uniform surface is obtained. The spraying equipment shall be of the
fully atomizing type equipped with a tank agitator. The compound shall
be thoroughly mixed with the pigment uniformly dispersed throughout the
storage tank. During application, the compound shall be stirred
continuously by effective mechanical means. Hand spraying of odd widths
or shapes and CTB surfaces exposed by the removal of forms is permitted.

The curing seal shall be maintained and protected until the pavement is
placed. Should the surface of the finished CTB and/or the curing seal
become damaged, additional curing material shall be applied at the time
it is damaged or when the damage is first observed.

304-5.11 PROTECTION. The Contractor shall protect the finished CTB
against traffic. Completed portions of the CTB layer can be opened
immediately to low-speed traffic and to construction equipment, provided
the curing material is not damaged and the CTB is sufficiently stable to
resist permanent deformation. Should the CTB be damaged, it shall be
replaced using full-depth patches, and sprayed with the selected curing
compound as described above. The CTB shall also be protected from
freezing at all times.

304-5.12 BOND-BREAKER. When the CTB is to be placed directly beneath
PCC, a bond-breaker shall be used. The bond-breaker shall be comprised
of choke stone material, as specified in paragraph 304-2.7, and placed
according to the new FAA specification for choke stone.

# MATERIAL ACCEPTANCE

304-6.1 ACCEPTANCE SAMPLING AND TESTING. All acceptance sampling and
testing, with the exception of thickness determination, necessary to
determine conformance with the requirements specified in this section
will be performed by the Engineer. The Contractor shall provide the
required CTB samples during construction for acceptance testing
purposes. The samples shall be taken in the presence of the Engineer.

Testing organizations performing these tests shall meet the requirements
of ASTM D 3666. All test equipment in Contractor-furnished laboratories
shall be calibrated by the testing organization prior to the start of
operations.

The CTB layer shall be tested for density, thickness, grade, and surface
tolerance on a lot basis, with a lot consisting of one of the following:

-   One day's production not to exceed \[2,000 yd^2^ (1,675 m^2^)\].

-   A half day's production, where a day's production consists of
    \[2,000 to 4,000 yd^2^ (1,675 to 3,350 m^2^)\].

Each lot shall be divided into four (4) equal sublots. Within each
sublot, one (1) set of density tests, one (1) thickness measurement, and
continuous surface straightedge tests (surface tolerance testing) shall
be performed, as described below. Sampling locations shall be determined
by the Engineer in accordance with the random sampling procedures
contained in ASTM D 3665.

In the event that only three (3) sublots are produced, the three sublots
shall constitute a complete lot. If one (1) or two (2) sublots are
produced for the same reason, they shall be incorporated into the next
or previous lot, and the total number of sublots shall be used in the
acceptance criteria calculation.

End-of-production sublots (i.e., sublots associated with the final
placement of CTB for the project and are less than a complete lot) shall
be handled as follows:

-   Three (3) sublots shall constitute a lot.

-   One (1) or two (2) sublots shall be incorporated into the previous
    lot.

*304-6.1.1 Density Testing*. CTB samples shall be taken from each sublot
and used to create laboratory test specimens representing the various
sublots. The specimens shall be tested for maximum density and optimum
moisture, in accordance with ASTM D 558. Using the maximum density
results for each sublot comprising a lot, an average maximum density for
the lot shall be determined, which will serve as the basis for
acceptance of the lot with regard to density.

Within each sublot in the field, one (1) in-place density test shall be
performed in accordance with ASTM D 1556, ASTM D 2167, or ASTM D 2922
and ASTM D 3017. The location of the test shall be randomly selected in
accordance with the procedures contained in ASTM D 3665. The in-place
density results for each sublot comprising the lot shall then be
averaged and compared with the corresponding average maximum density
determined in the lab. Acceptance criteria for CTB density are provided
in paragraph 304-6.2.1.

*304-6.1.2 Thickness Testing*. The CTB shall be tested for thickness
using the same lot and sublot designations established for density
testing. After 3 days of curing, one (1) 4-in (102-mm) diameter core per
sublot shall be obtained from a random location, as identified using the
procedures contained in ASTM D 3665. The thickness of each sampled core
shall be determined using the caliper measurement procedures provided in
ASTM C 174. The average thickness for the lot shall be determined using
the individual sublot core thicknesses. Acceptance criteria for CTB
thickness are provided in paragraph 304-6.2.2. At all locations where
cores have been drilled, the resulting core holes shall be filled by the
Contractor with CTB, HMA, or non-shrink grout.

*304-6.1.3 Grade Testing*. The elevations of the finished CTB shall be
surveyed every 25 ft (7.6 m) on both sides of the CTB lane as soon as it
has hardened sufficiently but before choke stone is applied. Acceptance
criteria for CTB grade are provided in paragraph 306-6.2.3.

*304-6.1.4 Surface Tolerance Testing*. As soon as the CTB has hardened
sufficiently but before choke stone is applied, it shall be tested for
surface tolerance with a 16-ft (4.9-m) straightedge or other approved
measuring device.

304-6.2 ACCEPTANCE CRITERIA. Acceptance of CTB will be based on density,
thickness, grade, and surface tolerance, as described in the paragraphs
below.

*304-6.2.1 Density Requirements*. With respect to density, each lot of
compacted material will be accepted without adjustment if the average
in-place density of the lot is equal to or greater than 98 percent of
the average maximum density determined for the lot in the laboratory.
Each lot of compacted CTB shall be accepted and payment adjusted in
accordance with Table 3.

Table 3. Sliding pay scale factors for density.

  --------------------------------------- -------------------------------
  **Average Dry Density (%)**             **Payment (%)**

  98.0 and greater                        100

  97.0 - 97.9                             95

  96.0 - 96.9                             90

  95.0 - 95.9                             75

  Less than 95.0                          Reject
  --------------------------------------- -------------------------------

If the average density is below 95 percent, the lot will be rejected and
shall be removed and replaced at the Contractor's expense. In
multi-layer construction, density shall be tested for each lift, and all
lifts within a rejected lot shall be removed and replaced. No payment
shall be made for removed lifts. Replacement lifts shall be paid in
accordance with this section.

*304-6.2.2 Thickness Requirements*. The completed thickness shall be as
shown on the plans. When the average lot thickness is not deficient by
more than ½ in (12.5 mm) from the plan thickness, full payment shall be
made. If the average lot thickness is deficient by more than 1 in (25.4
mm), it shall be removed and replaced at the Contractor's expense. When
such measurement is deficient by more than ½ in (12.5 mm) but less than
1 in (25.4 mm) from the plan thickness, one additional core shall be
taken at random from each sublot within the lot. The thickness of these
additional cores shall be determined as indicated in paragraph
304-6.1.2. A new average lot thickness shall be recomputed based on
these additional cores and the original cores taken from each sublot. If
the recomputed average lot thickness is not deficient by more than ½ in
(12.5 mm) from the plan thickness, full payment shall be made. If the
average lot thickness is deficient by more than ½ in (12.5 mm) from the
plan thickness, the entire lot shall be removed and replaced at the
Contractor\'s expense or shall be permitted to remain in-place at an
adjusted payment of 75 percent of the contract unit price.

When the measured thickness is more than that indicated on the plans, it
will be considered as conforming to the requirements, provided the
surface of the completed CTB layer is within the established grade and
surface tolerance requirements.

*304-6.2.3 Grade Requirements*. When the completed surface is higher
than ½ in (12.5 mm) above the grade shown in the plans, the surface
shall be trimmed, at the Contractor's expense, with an approved grinding
machine to an elevation that falls within a tolerance of ¼ in (6 mm) or
less.

*304-6.2.4 Surface Tolerance Requirements*. The finished surface, as
determined before choke stone is applied, shall not vary more than ⅜ in
(9.5 mm) when tested with a 16-ft (4.9-m) straightedge applied parallel
with, or at right angles to, the centerline of the CTB area. Areas in
the CTB showing high spots greater than ⅜ in (9.5 mm) over 16 ft (4.9 m)
shall be marked and immediately trimmed with an approved grinding
machine. Such trimming shall be at the Contractor's expense.

# METHOD OF MEASUREMENT

304-7.1 CEMENT-TREATED BASE COURSE. The quantity of cement-treated base
course to be paid for will be determined by measurement of the number of
\[yd^2^ (m^2^)\] of CTB actually constructed and accepted by the
Engineer as complying with the plans and specifications.

# BASIS OF PAYMENT

304-8.1 CEMENT-TREATED BASE COURSE. Payment shall be made at the
contract unit price per \[yd^2^ (m^2^)\] for cement-treated base course.
This price shall be full compensation for furnishing all materials,
except cement; for all preparation, manipulation, placing, and curing of
these materials; and for all labor, equipment, tools, and incidentals
necessary to complete the item.

Each lot of CTB material will be accepted for density at the full
contract price adjusted in accordance with Table 3 in paragraph
304-6.2.1.

Payment will be made for cement-treated base course\--per \[yd^2^
(m^2^)\].

# TESTING REQUIREMENTS

ASTM C 88 Soundness of Aggregates by Use of Sodium Sulfate or

Magnesium Sulfate

ASTM C 131 Resistance to Degradation of Small-Size Coarse Aggregate

by Abrasion and Impact in the Los Angeles Machine

ASTM C 136 Sieve or Screen Analysis of Fine and Coarse Aggregate

ASTM C 174 Measuring Thickness of Concrete Elements Using Drilled

Concrete Cores

ASTM C 1260 Potential Alkali Reactivity of Aggregates (Mortar-Bar
Method)

ASTM D 75 Sampling Aggregates

ASTM D 558 Moisture-Density Relations of Soil-Cement Mixtures

ASTM D 559 Test Methods for Wetting & Drying Compacted Soil Cement

Mixtures

ASTM D 560 Freezing-and-Thawing Tests of Compacted Soil-Cement Mixtures

ASTM D 1556 Density of Soil in Place by the Sand-Cone Method

ASTM D 1633 Compressive Strength of Molded Soil-Cement Cylinders

ASTM D 2167 Density of Soil in Place by the Rubber-Balloon Method

ASTM D 2922 Density of Soil and Soil-Aggregate in Place by Nuclear
Methods

ASTM D 3017 Water Content of Soil and Rock in Place by Nuclear Methods

ASTM D 3665 Random Sampling of Paving Materials

ASTM D 3666 Minimum Requirements for Agencies Testing and Inspecting

Road and Paving Materials

ASTM D 4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils

AASHTO T 26 Quality of Water to be Used in Concrete

# MATERIAL REQUIREMENTS

ASTM C 150 Portland Cement

ASTM C 309 Liquid Membrane-Forming Compounds for Curing Concrete

ASTM C 595 Blended Hydraulic Cements

ASTM C 618 Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as
a

Mineral Admixture in Concrete

ASTM C 989 Ground Granulated Blast-Furnace Slag for Use in Concrete

and Mortars

ASTM D 977 Emulsified Asphalt

ASTM D 2397 Cationic Emulsified Asphalt

Appendix B

Final Draft UPDATE of Item P-306

Econocrete Base Course

# DESCRIPTION

306-1.1 This item shall consist of a subbase material, herein termed
econocrete, that is composed of aggregate and cement uniformly blended
together and mixed with water. The mixture may also include approved
cementitious additives, in the form of fly ash or slag, and chemical
admixtures. The mixed material shall be spread, shaped, and consolidated
using concrete paving equipment in accordance with these specifications
and in conformity to the lines, grades, dimensions, and typical
cross-sections shown on the plans.

# MATERIALS

306-2.1 AGGREGATE. The coarse aggregate fraction shall be crushed stone,
crushed or uncrushed gravel, crushed and adequately seasoned,
air-cooled, iron blast furnace slag, crushed recycled concrete pavement,
or a combination thereof. The fine aggregate fraction may be part of the
natural aggregate blend as obtained from the borrow source or it may be
natural sand that is added at the time of mixing.

The aggregate shall consist of hard, durable particles, free from an
excess of flat, elongated, soft, or disintegrated pieces, or
objectionable matter (e.g., roots, sod, weeds, organic impurities,
etc.). A flat particle is one having a ratio of width to thickness
greater than five; an elongated particle is one having a ratio of length
to width greater than five.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer should specify limits for deleterious materials using
> guidance contained in ASTM C 33.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

The design aggregate blend shall conform to one of the gradations shown
in Table 1, when tested in accordance with ASTM C 136.

Table 1. Aggregate gradation for econocrete.

+--------------------+------------------------+------------------------+
| **Sieve Size**     | **Percentage by Weight |                        |
|                    | Passing Sieves**       |                        |
| **(square          |                        |                        |
| openings)**        |                        |                        |
+--------------------+------------------------+------------------------+
|                    | **1½ -in (37.5-mm)     | **1-in (25-mm)         |
|                    | Maximum**              | Maximum**              |
+--------------------+------------------------+------------------------+
| 2 in (51 mm)       | \--                    | \--                    |
|                    |                        |                        |
| 1½ in (37.5 mm)    | 100                    | \--                    |
|                    |                        |                        |
| 1 in (25 mm)       | 70 - 95                | 100                    |
|                    |                        |                        |
| ¾ in (19 mm)       | 55 - 85                | 70 - 100               |
|                    |                        |                        |
| No. 4 (4.75 mm)    | 30 - 60                | 35 - 65                |
|                    |                        |                        |
| No. 40 (425 µm)    | 10 - 30                | 15 - 30                |
|                    |                        |                        |
| No. 200 (75 µm)    | 0 - 15                 | 0 -- 15                |
+--------------------+------------------------+------------------------+

*306-2.1.1 Reactivity.* Both coarse and fine aggregate shall be tested
by the Contractor for

alkali-aggregate reactivity in accordance with ASTM C 1260. The
aggregate used for testing shall be the coarse aggregate (all size
groups) and fine aggregate that will be used for the work. Should the
test data indicate an expansion of greater than 0.10 percent at 16 days,
the Contractor may propose mitigation.

306-2.2 CEMENT. Cement shall conform to the requirements of ASTM \[ \].

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer shall specify ASTM C 150 Type I, II, III, IV, or V or
> ASTM C 595 Type IS, IS-A, IP, IP-A, P, or PA. Type II cement shall be
> specified in areas with a history of sulfate reaction with the
> selected aggregate.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

306-2.3 CEMENTITIOUS ADDITIVES. Pozzolanic and ground granulated blast
furnace (GGBF) slag may be added to the econocrete mix. If used, each
material must meet the following requirements:

a.  Pozzolan. Pozzolanic materials must meet the requirements of ASTM C
    618, Class F Flyash.

b.  GGBF Slag. Slag shall conform to ASTM C 989, Grade 80, 100 or 120.

306-2.4 CHEMICAL ADMIXTURES. The Contractor shall submit certificates
indicating that the material to be furnished meets all the requirements
listed below. In addition, the Engineer may require the Contractor to
submit complete test data showing that the material to be furnished
meets all the requirements of the cited specification.

a.  Air-Entraining Admixtures. Air-entraining admixtures shall meet the
    requirements of ASTM C 260.

b.  Water-Reducing Admixtures. Water-reducing, set-controlling
    admixtures shall meet the requirements of ASTM C 494, Type A,
    water-reducing or Type D, water-reducing and retarding.
    Water-reducing admixtures shall be added at the mixer separately
    from air-entraining admixtures in accordance with the
    manufacturer\'s printed instructions. The air entrainment agent and
    the water-reducing admixture shall be compatible.

306-2.5 WATER. Water used in mixing or curing shall be clean and free of
oil, salt, acid, alkali, sugar, vegetable, or other deleterious
substances injurious to the finished product. Water will be tested in
accordance with the requirements of AASHTO T 26. Water known to be of
potable quality may be used without testing.

306-2.6 CURING MATERIALS. For curing econocrete, use white-pigmented,
liquid membrane-forming compound conforming to ASTM C 309, Type 2, Class
A or Class B (wax-based).

306-2.7 CHOKE STONE. Choke stone shall be used as a bond-breaker between
the econocrete and PCC surface. It shall conform to the requirements of
the new FAA specification for choke stone.

# composition of Mixture

306-3.1 MIX DESIGN. The econocrete mix design shall be based on trial
batch results conducted in the laboratory. The econocrete shall be
designed to meet the criteria in this section.

*306-3.1.1 Compressive Strength.* Compressive strength shall not be less
than 500 psi (3,445 kPa) nor greater than 800 psi (5,516 kPa) at 7 days.
The 7-day strength shall be taken as the average of two compressive
strength test results. All compressive strength specimens shall be
prepared and tested in accordance with ASTM C 192 and ASTM C 39,
respectively.

If the minimum strength value is not achieved within the specified time,
the material is not subject to removal, but further construction and
other traffic will only be allowed on the surface when the compressive
strength is at least 350 psi (2,413 kPa). Laboratory tests can be used
to determine when the strength is obtained.

If the 3-day strength is greater than 500 psi (3,447 kPa), the
Contractor shall notch transverse joints in the econocrete layer in
accordance with paragraph 306-5.10.2.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> In locations subject to freeze-thaw cycles, insert the following "The
> freeze-thaw weight loss shall not exceed 14 percent when tested in
> accordance with ASTM D 560."
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

If there is a change in aggregate sources, type of cement used, or
pozzolanic materials, a new mix design must be submitted.

*306-3.1.2 Air Content.* The percentage of air entrainment shall be 6
percent. Air content shall be determined by testing in accordance with
ASTM C 231 for gravel and stone coarse aggregate and ASTM C 173 for slag
and other highly porous coarse aggregate.

306-3.2 SUBMITTALS. At least \[ \] days prior to the placement of the
econocrete, the Contractor shall submit certified test reports to the
Engineer for those materials proposed for use during construction, as
well as the mix design information for the econocrete material. Tests
older than 6 months shall not be used. The certification shall show the
appropriate ASTM or AASHTO specifications or tests for the material, the
name of the company performing the tests, the date of the tests, the
test results, and a statement that the material did or did not comply
with the applicable specifications. The submittal package shall include
the following:

a.  Sources of materials, including aggregate, cement, admixtures, and
    curing and bond breaking materials.

b.  Physical properties of the aggregates, cement, admixtures, curing
    and bond breaking materials.

c.  Mix design.

-   mix identification number.

-   weight of saturated surface-dry aggregates (fine and coarse).

-   combined aggregate gradation.

-   cement factor.

-   water content.

-   water-cementitious material ratio (by weight).

-   volume of admixtures and yield for one cubic yard (cubic meter) of
    econocrete.

d.  Laboratory test results.

-   slump.

-   air content.

-   compressive strength at 3, 7, and 28 days (average values).

-   wet/dry and/or freeze-thaw weight loss (when applicable).

In addition, where applicable, the Contractor shall submit for approval
by the Engineer a jointing plan for transverse joints in the econocrete
layer.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Insert the appropriate number of days for Contractor submittal of the
> certified test reports and the mix design; 15 to 30 days is typical.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

# 

# EQUIPMENT

306-4.1 All equipment necessary to mix, transport, place, compact, and
finish the econocrete material shall be furnished by the Contractor. The
equipment shall be subject to inspection and approval by the Engineer.

306-4.2 MIXING. Econocrete may be mixed in a stationary mixer, either at
a central batch plant or at the site, or in a truck mixer. The mixer
type and capacity shall be inspected and approved by the Engineer before
production begins. Each mixer shall have attached in a prominent place a
manufacturer\'s nameplate showing the capacity of the drum in terms of
volume of mixed concrete and the speed of rotation of the mixing drum or
blades.

*306-4.2.1 Stationary Plant Mixer*. The batch plant and equipment shall
conform to the requirements of ASTM C 94. Unrestricted access to the
plant must be provided to the Engineer at all times for inspection of
the plant's equipment and operation and for sampling the econocrete
mixture and its components.

The mixers shall be examined daily for changes in condition due to
accumulation of hard concrete or mortar or wear of blades.

*306-4.2.2 Truck Mixers.* Truck mixers used for mixing econocrete shall
conform to the requirements of ASTM C 94. Econocrete may be entirely
mixed in a truck mixer or partially mixed in a stationary mixer with
mixing completed in a truck mixer. Truck mixers shall be equipped with
an accurate continuous registering electronically or mechanically
activated revolution counter, by which the number of drum revolutions
may be verified.

306-4.3 HAULING. Mixed econocrete shall be hauled from the stationary
plant to the job site in a truck agitator, a truck mixer operating at
agitating speed, or a non-agitating truck. All equipment shall conform
to the requirements of ASTM C 94. When truck mixers are used to mix
econocrete, they may be transported to the job site in the same truck
operating at agitating speeds, truck agitators, or a non-agitating
truck. The bodies of non-agitating trucks shall be smooth, metal
containers and shall be capable of discharging the concrete at a
satisfactory controlled rate without segregation.

306-4.4 PLACING AND FINISHING.

*306-4.1 Forms*. Straight side forms shall be made of steel and shall be
furnished in sections not less than 10 ft (3.1 m) in length. Forms shall
have a depth equal to the pavement thickness at the edge. Flexible or
curved forms of proper radius shall be used for curves of 100-ft (31-m)
radius or less. Forms shall be provided with adequate devices for secure
settings so that when in place they will withstand, without visible
spring or settlement, the impact and vibration of the consolidating and
finishing equipment. Forms with battered top surfaces and bent, twisted
or broken forms shall not be used. Built-up forms shall not be used,
except as approved by the Engineer.

The top face of the form shall not vary from a true plane more than ⅛ in
(3 mm) in 10 ft (3.1 m), and the upstanding leg shall not vary more than
¼ in (6 mm). The forms shall contain provisions for locking the ends of
abutting sections together tightly for secure setting. Wood forms may be
used under special conditions, when accepted by the Engineer.

*306-4.4.2 Pavers*. Econocrete can be placed using fixed forms or
slip-form pavers. The paver shall be fully energized, self-propelled and
capable of spreading, consolidating, and finishing the econocrete
material, true to grade, tolerances, and cross sections. The paver shall
be capable of finishing the surface so that hand finishing is not
required. The paver shall be of sufficient weight and power to construct
the maximum specified concrete paving lane width, at adequate forward
speed, without transverse, longitudinal or vertical instability or
without displacement. The slip-form paver shall be equipped with
electronic or hydraulic horizontal and vertical control devises
utilizing guide wires or stringlines on both sides of the machine. Slope
control will not be allowed.

a.  Concrete Pavers. Concrete pavers are approved as paver-finishing
    machines for econocrete, providing they are capable of handling the
    amount of econocrete required for the full-lane width specified, and
    consolidating the econocrete full depth. A concrete paver is a
    power-driven machine with augers, strike-off and tamper bars ahead
    of a pan screed, with at least one trailing oscillating screed or
    belt finisher.

b.  Bridge Deck Pavers. Bridge deck pavers are approved as
    paver-finishing machines for econocrete, providing they are capable
    of handling the amount of econocrete required for the full-lane
    width specified, and consolidating the econocrete full depth. A
    bridge deck paver is an automatic truss paving machine, with paving
    carriage that strikes off, vibrates, paves, and textures the
    econocrete with augers, internal vibration, paving rollers, and drag
    pan.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Econocrete is a weak concrete mix. As such, it should be placed with
> pavers suitable for paving concrete pavements. Rotating pipe and tube
> floats are not suitable for this type of pavement.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

306-4.5 CONSOLIDATION. For side-form construction, vibrators may be
either the surface pan type for pavements less than 8 in (203 mm) thick
or the internal type with either immersed tube or multiple spuds for the
full width of the slab. They may be attached to the spreader or the
finishing machine, or they may be mounted on a separate carriage. They
shall not come in contact with the joint, subgrade, or side forms.

For slip-form construction, the paver shall vibrate the econocrete for
the full width and depth of the strip of pavement being placed.
Vibration shall be accomplished by internal vibrators.

The number, spacing, frequency, and eccentric weights of vibrators shall
be provided as necessary to achieve an acceptable consolidation and
finishing quality. Adequate power to operate all vibrators at the weight
and frequency required for a satisfactory finish shall be available on
the paver. The internal vibrators may be supplemented by vibrating
screeds operating on the surface of the econocrete. The Contractor shall
constantly monitor the frequency of each of the individual vibrators
using electronic means and shall provide constant monitoring of the
consolidation process to avoid honeycombing or over-consolidation. Areas
that are visually determined to be honeycombed or over-consolidated
shall be corrected at the Contractor's expense.

The vibrators and tamping elements shall be automatically controlled so
that they stop operation as forward motion ceases. Any override switch
shall be of the spring-loaded, momentary-contact type.

Hand held vibrators may be used in irregular areas.

306-4.6 JOINTING. The Contractor shall provide sawing equipment adequate
in number of units and power to produce contraction or construction
joints of the required dimensions as shown on the plans. The Contractor
shall provide at least one standby saw in good working order and a
supply of saw blades at the site of the work at all times during sawing
operations.

# CONSTRUCTION METHODs

306-5.1 WEATHER LIMITATIONS.

*306-5.1.1 Cold Weather.* Unless authorized by the Engineer, the
temperature of the mixed econocrete shall not be less than 50°F (10°C)
at the time of placement. In addition, the econocrete shall not be
placed when the ambient temperature is below 40°F (4°C) or when
conditions indicate that the temperature may fall below 35°F (2°C)
within 24 hours. Under no circumstances shall the econocrete be placed
on frozen underlying courses or mixed when the aggregate is frozen.

When mixing and placing is authorized during cold weather, the Engineer
may require the water and/or the aggregates to be heated to not less
than 70°F (20°C) nor more than 150°F (66°C). The aggregates may be
heated by either steam or dry heat prior to being placed in the mixer.
The apparatus used shall heat the mass uniformly and shall be arranged
to preclude the possible occurrence of overheated areas which might be
detrimental to the materials.

*306-5.1.2 Hot Weather.* To prevent rapid drying of newly constructed
econocrete, the econocrete temperature from initial mixing through final
cure shall not exceed 90°F (32°C). The aggregates and/or mixing water
shall be cooled as necessary to maintain the econocrete temperature at
or not more than the specified maximum. Ice or ice water may be
substituted for the mixing water for this purpose.

In addition, during periods of warm weather when the maximum daily air
temperature exceeds 85°F (30°C), the forms and/or the underlying
material shall be sprinkled with water immediately before placing the
econocrete.

*306-5.1.3 Rain.* All mixing and batching operations should be halted
during rain showers and any plastic econocrete placed should be covered
immediately. The econocrete shall be kept covered with plastic sheeting
or other waterproof material until such time that the rain does not make
any surface indentation on the econocrete layer. Areas damaged by rain
shall be refinished or replaced.

306-5.2 FORM SETTING. Forms shall be set sufficiently in advance of the
econocrete placement to ensure continuous paving operation. After the
forms have been set to correct grade, the grade shall be thoroughly
tamped, either mechanically or by hand, at both the inside and outside
edges of the base of the forms. Forms shall be staked into place with
not less than 3 pins for each 10-ft (3.1-m) section. A pin shall be
placed at each side of every joint.

Form sections shall be tightly locked and shall be free from play or
movement in any direction. The forms shall not deviate from true line by
more than ¼ in (6 mm) at any joint. Forms shall be so set that they will
withstand, without visible spring or settlement, the impact and
vibration of the consolidating and finishing equipment. Forms shall be
cleaned and oiled prior to the placing of econocrete.

The alignment and grade elevations of the forms shall be checked and
corrections made by the Contractor immediately before placing the
econocrete. When any form has been disturbed or any grade has become
unstable, the form shall be reset and rechecked.

306-5.3 PREPARATION OF UNDERLYING COURSE. The underlying course shall be
checked by the Engineer before placing and spreading operations are
started, in order to ensure that it is free of any ruts, depressions, or
bumps and is finished to the correct grade. Any ruts or soft yielding
places in the underlying course caused by improper drainage conditions,
hauling, or any other cause, shall be corrected at the Contractor's
expense before the econocrete mixture is placed thereon. The underlying
course should be wetted down in advance of placing the econocrete to
ensure a firm, moist condition at the time of econocrete placement. The
underlying course shall be protected from frost. Usage of chemicals to
eliminate frost is not permissible.

306-5.4 GRADE CONTROL. Grade control between the edges of the pavement
shall be accomplished by grade stakes, steel pins or forms placed in
lanes parallel to the centerline and at intervals of 50 ft (15.3 m) or
less on the longitudinal grade and at 25 ft (7.6 m) or less on the
transverse grade. To protect the underlying course and ensure proper
drainage, the econocrete paving shall begin along the centerline of the
pavement on a crowned section or on the greatest contour elevation of a
pavement with variable cross slope.

306-5.5 HANDLING, MEASURING, AND BATCHING MATERIAL. The batch plant
site, layout, equipment, and provisions for transporting material shall
assure a

continuous supply of material to the work. Stockpiles shall be
constructed in a manner that prevents segregation and intermixing of
deleterious materials.

Aggregates that have become segregated or mixed with earth or foreign
material shall not be used. All aggregates produced or handled by
hydraulic methods, and washed aggregates, shall be stockpiled or binned
for draining at least 12 hours before being batched. Rail shipments
requiring more than 12 hours transit will be accepted as adequate
binning only if the car bodies permit free drainage.

Batching plants shall be equipped to proportion aggregates and bulk
cement, by weight, automatically using interlocked proportioning devised
of an approved type. When bulk cement is used, the Contractor shall use
a suitable method of handling the cement from weighing hopper to
transporting container or into the batch itself for transportation to
the mixer, such as a chute, boot or other device approved by the
Engineer, to prevent loss of cement. The device shall be arranged to
provide positive assurance that the required cement content is present
in each batch.

306-5.6 MIXING. All econocrete shall be mixed and delivered to the site
in accordance with the requirements of ASTM C 94. The mixing time should
be adequate to produce econocrete that is uniform in appearance, with
all ingredients evenly distributed. Mixing time shall be measured from
the time all materials are emptied into the drum (provided all the water
is added before one-fourth the preset mixing time has elapsed) and
continues until the time the discharge chute is opened to deliver the
econocrete.

If mixing in a plant, the mixing time shall not be less than 50 nor
greater than 90 seconds. If mixing in a truck, the mixing time shall not
be less than 70 nor more than 125 truck-drum revolutions at a mixing
speed of not less than 6 nor more than 18 truck-drum revolutions per
minute.

Retempering econocrete by adding water or by other means will not be
permitted, except when econocrete is delivered in truck mixers. With
truck mixers, additional water may be added to the batch materials and
additional mixing performed to allow proper placement of the material,
provided (a) the addition of water is performed within 45 minutes after
the initial mixing operations and (b) the water/cementitious ratio
specified in the mix design is not exceeded.

306-5.7 HAULING. The elapsed time from the addition of cementitious
material to the mix until the econocrete is deposited in place at the
work site shall not exceed 45 minutes when the concrete is hauled in
nonagitating trucks, nor 90 minutes when it is hauled in truck mixers or
truck agitators.

306-5.8 PLACING, CONSOLIDATING, AND FINISHING. Prior to placement of the
econocrete layer, the prepared underlying course shall be well moistened
with water, without saturating, in order to prevent rapid loss of
moisture from the econocrete. In cold weather, the underlying course
shall be protected so that it will be entirely free of frost when
econocrete is placed.

The Contractor has the option of side- (fixed-) form or slip-form
paving. Under both techniques, the hauled econocrete material shall be
discharged onto the prepared underlying course such that segregation of
the mix is minimized and minimum handling of the mix is needed.
Placement of the econocrete material shall be continuous between
construction joints. Workers shall not be allowed to walk in the freshly
mixed econocrete with boots or shoes coated with earth or debris.

Econocrete shall not be mixed, placed, or finished when the natural
light is insufficient, unless an adequate artificial lighting system is
provided.

*306-5.8.1 Side-Form Construction*. For side-form placement, the
Contractor shall verify the elevations of the fixed forms such that the
thickness and finished grade of the econocrete layer will be in
accordance with the requirements of the project plans and
specifications. The econocrete shall be spread uniformly between the
forms, immediately after it is placed using a spreading machine.
Necessary hand spreading shall be done with shovels, not rakes.

The spreading shall be followed immediately by thorough consolidation
using vibrating screeds or spud vibrators. Vibrators may be external or
internal type, depending on the thickness of the econocrete layer. The
surface vibrators may be attached to the spreader or they may be mounted
on a separate carriage. They shall not come in contact with the joint,
subgrade, or side forms. When spud vibrators are used, the econocrete
shall be thoroughly consolidated against and along the faces of all
forms and previously placed econocrete. Vibrators shall not be permitted
to come in contact with a joint assembly, the grade, or a side form. In
no case shall the vibrator be operated longer than 20 seconds in any one
location, nor shall the vibrators be used to move the econocrete.

Hand finishing will not be permitted except in areas where the
mechanical finisher cannot operate.

*306-5.8.2 Slip-Form Construction*. For slip-form construction, the
Contractor shall verify the elevations of the guide wires controlling
slip-form pavers such that the thickness and finished grade of the
econocrete will be in accordance with the requirements of the project
plans and specifications. The slip-form paver should spread,
consolidate, and shape the freshly placed econocrete in one complete
pass of the machine. The machine shall vibrate and finish the econocrete
for the full width and depth of the layer.

FINAL FINISHING. Final finishing shall be accomplished while the
econocrete is still in the plastic state. Limited surface refinishing by
hand is acceptable to meet the grade and surface tolerance established
in paragraphs 306-6.2.3 and 306-6.2.4, after strike off and
consolidation.

If the overlying layer is to be PCC pavement, the surface of the
econocrete shall not be textured. If the overlying layer is to be HMA
pavement, and if the bond between the HMA layer and the econocrete is
considered important for pavement performance, tining or scarifying the
surface to provide a coarse texture may be permitted.

306-5.10 JOINTS. Joints shall be constructed as shown on the plans. If
joints are not shown on the plans, the Contractor may elect to propose a
jointing plan for approval by the Engineer.

*306-5.10.1 Construction Joints[.]{.underline}* Locate all longitudinal
and transverse construction joints as shown on the plans. If
longitudinal joints are not shown, locate longitudinal joints within 6
in (152 mm) from planned joints in the PCC to be placed over the
econocrete.

*306-5.10.2 Contraction Joints*. If elected by the Contractor,
transverse contraction joints can be constructed by sawing the hardened
econocrete to a depth of at least one-third the thickness of the
econocrete base. These joints shall match within 3 in (76 mm) the
planned joints of the overlying concrete surface.

306-5.11 CURING. Immediately after the finishing operations are complete
and within 2 hours of placement of the econocrete, the entire surface
and edges of the newly placed econocrete shall be sprayed uniformly with
white pigmented, liquid membrane forming curing compound. The layer
should be kept moist using a moisture-retaining cover or a light
application of water until the curing material is applied. The curing
compound shall not be applied during rainfall.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Excessive delays in applying the curing compound can result in
> uncontrolled shrinkage cracking, which can reflect into the overlying
> pavement over time.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

The curing material shall be applied using mechanical sprayers under
pressure at the rate of 1 gal (3.8 L) to not more than 200 ft^2^ (18.6
m^2^). The spraying equipment shall be of the fully atomizing type
equipped with a tank agitator. At the time of use, the compound in the
tank shall be in a thoroughly mixed condition with the pigment uniformly
distributed throughout the vehicle. During application the compound
shall be stirred continuously by mechanical means.

Hand spraying of odd widths or shapes and econocrete surfaces exposed by
the removal of forms is permitted.

Should the film of curing material become damaged from any cause,
including sawing operations, within the required 28-day curing period or
until the overlying course is constructed, the damaged portions shall be
repaired immediately with additional compound or other approved means as
quickly as practical.

Edges of the econocrete layer shall be sprayed with curing compound
immediately following placement with slip-form pavers or when fixed
forms are removed.

*306-5.11.1 Curing in Cold Weather*. The econocrete shall be maintained
at a temperature of at least 50°F (10°C) for a period of 72 hours after
placing and at a temperature above freezing for the remainder of the
curing time. The Contractor shall be responsible for the quality and
strength of the econocrete placed during cold weather, and any
econocrete injured by frost action shall be removed and replaced at the
Contractor\'s expense.

*306-5.11.2 Curing in Hot Weather*. When econocrete is being placed and
the air temperature may be expected to rise above 90°F (32°C) shortly
after placement, the econocrete layer should be cured as quickly as
possible to allow curing without the formation of excessive shrinkage
cracks.

306-5.12 PROTECTION. The Contractor shall protect the pavement and its
appurtenances against both public traffic and traffic caused by the
Contractor's employees and agents. The Engineer shall decide when the
pavement shall be opened to traffic. Traffic shall not be allowed on the
pavement until test specimens molded and cured in accordance with ASTM C
31 have attained a compressive strength of 350 psi (2,413 kPa) when
tested by ASTM C 39. The econocrete surface shall be protected from foot
and vehicular traffic and other sources of abrasion until such a time.
During this time, the econocrete layer shall be protected from injurious
action by sun, rain, flowing water, frost, or mechanical injury. After
this period, construction traffic to place the overlying layers may be
allowed.

306-5.13 BOND-BREAKER. When the econocrete is to be placed directly
beneath PCC

pavement, a bond-breaker shall be used. A second application of the
curing compound shall be applied to the econocrete layer to serve as a
bond-breaker when the 7-day compressive strength values satisfy the
minimum and maximum requirements stated in paragraph 306-3.1. This
application shall be made at least 8 hours and not more than 24 hours
prior to beginning the placement of the PCC pavement. The rate of
application shall be the same as that specified for the curing
application. After application of the bond-breaker coat, traffic will be
limited to that required for the placement of the overlying pavement
layer.

[]{.mark}

If the maximum 7-day compressive strength values exceed the maximum
strength requirements when evaluated in accordance with paragraph
306-6-2.1, choke stone shall serve as a bond-breaker. This material
shall be as specified in paragraph 306-2.7 and shall be placed according
to the new FAA specification for choke stone.

# 

# MATERIAL ACCEPTANCE

306-6.1 ACCEPTANCE SAMPLING AND TESTING. All acceptance sampling and

testing, with the exception of coring for thickness determination,
necessary to determine conformance with the requirements specified in
this section will be performed by the Engineer. The Contractor shall
provide the required econocrete samples during construction for
acceptance testing purposes. The samples shall be taken in the presence
of the Engineer.

The econocrete layer shall be tested for air content, strength,
thickness, grade, and surface tolerance. Sampling and testing for air
shall be as specified in paragraph 306-6.1.1. Sampling and testing for
strength, thickness, grade, and surface tolerance shall be on a lot
basis, with a lot consisting of one of the following:

-   One day's production not to exceed 2,000 yd^2^ (1,675 m^2^).

-   A half day's production, where a day's production is expected to
    consist of between 2,000 and 4,000 yd^2^ (1,675 and 3,350 m^2^).

Each lot will be divided into four equal sublots. In the event that only
three (3) sublots are produced, the three sublots shall constitute a
complete lot. If, only one (1) or two (2) sublots are produced, they
shall be incorporated into the next lot, and the total number of sublots
shall be used in the acceptance plan calculation.

End-of-production sublots (i.e., sublots associated with the final
placement of econocrete for the project and are less than a complete
lot) shall be handled as:

-   Three (3) sublots shall constitute a lot.

-   One (1) or (2) sublots shall be incorporated into the previous lot.

*306-6.1.1 Air Content* Testing. Air content tests shall be performed on
the first three truckloads of econocrete produced at the start of
operations each day and the first three truckloads produced after any
scheduled or non-scheduled shutdown. Additional tests shall be performed
each time a sample is taken for a strength test and when requested by
the Engineer.

Air content tests shall be made in accordance with ASTM C 231. Air
content test results shall be between 4 and 8 percent.

If the first test on a truckload of econocrete is not within the
specification limits, a second test on the same truckload shall be made.
If the second test is within the specification limits, the econocrete
will be accepted with respect to entrained air content. If the second
test is not within the specification limits, the truckload shall be
rejected.

*306-6.1.2 Compressive Strength Testing.* One sample of freshly
delivered econocrete shall be taken from each sublot for compressive
strength testing. The econocrete shall be sampled in accordance with
ASTM C 172. Sampling locations shall be determined in accordance with
the random sampling procedures contained in ASTM D 3665.

At least two (2) test cylinders shall be made from each sample in
accordance with ASTM C 31. The 7-day compressive strength of each
cylinder shall be determined in accordance with ASTM C 39.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Since the strength level of econocrete at an early age is considerably
> lower than PCC, special care is required in handling test specimens.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

The Contractor shall provide adequate facilities for the initial curing
of cylinders. During the 24 hours after molding, the temperature
immediately adjacent to the specimens must be maintained in the range of
60 to 80°F (16 to 27°C), and loss of moisture from the specimens must be
prevented. The specimens may be stored in tightly constructed wooden
boxes, damp sand pits, temporary buildings at construction sites, under
wet burlap in favorable weather or in heavyweight closed plastic bags,
or use other suitable methods, provided the temperature and moisture
loss requirements are met.

The compressive strength for each sublot shall be computed by averaging
the 7-day compressive strengths of the two test cylinders representing
that sublot. The compressive strength of the lot shall be the average
compressive strength of the individual sublots comprising the lot.

Specimens that are noticeably defective shall not be considered in the
determination of the strength. If the test specimens fail to conform to
the requirements for strength, the Engineer shall request changes in the
econocrete mixture to increase the strength to meet the requirements.

*306-6.1.3 Thickness Testing*. After the econocrete base has cured for 3
days, one (1) 4-in (102-mm) diameter core per sublot shall be obtained
from a random location, as identified using the procedures contained in
ASTM D 3665. The thickness of each sampled core shall be determined
using the caliper measurement procedures provided by ASTM C 174. The
average thickness for the lot shall be determined using the individual
sublot core thicknesses. Acceptance criteria for econocrete thickness
are provided in paragraph 306-6.2.2.

When such measurement is deficient more than ½ in (12.5 mm) and not more
than 1 in (25.4 mm) from the plan thickness, two additional cores shall
be taken at random and used in determining the average thickness for
that lot. The thickness of the cores shall be determined by average
caliper measurement of cores tested in accordance with ASTM C 174.

At all locations where cores have been drilled, the resulting holes
shall be filled with econocrete or non-shrink grout material, as
approved by the Engineer.

*306-6.1.4 Grade Testing*. The elevations of the finished econocrete
shall be surveyed on both sides of the econocrete lane, every 25 ft (7.6
m).

*306-6.1.5 Surface Tolerance Testing*. After the econocrete has hardened
sufficiently, it shall be tested for surface tolerance with a 16-ft
(4.9-m) straightedge provided by the Contractor.

306-6.2 ACCEPTANCE CRITERIA. Acceptance of econocrete will be based on
compressive strength, thickness, grade, and surface tolerance, as
described in the paragraphs below.

*306-6.2.1 Compressive Strength Requirements*. The econocrete shall meet
all of the following compressive strength requirements on a lot basis:

-   The compressive strength of the lot, tested at 7 days, shall be
    greater than 500 psi (3,445 kPa). When a given lot of econocrete
    fails to meet the minimum compressive strength requirements, the
    entire lot shall be replaced at the Contractor's expense.

-   Not more than 20 percent of the individual cylinders in a given lot,
    tested at 7 days, shall have a compressive strength greater than 800
    psi (5,512 kPa). When greater than 20 percent of the individual
    cylinders in a given lot have 7-day compressive strengths in excess
    of 800 psi (5,512 kPa), and transverse joints have not been notched,
    a choke stone layer shall be used as a bond-breaker.

*306-6.2.2 Thickness Requirements*. The completed thickness shall be as
shown on the plans. When the average lot thickness is not deficient by
more than ½ in (12.5 mm) from the plan thickness, full payment shall be
made. If the lot average thickness is deficient by more than 1 in (25.4
mm), it shall be removed and replaced at the Contractor's expense. When
such measurement is deficient more than ½ in (12.5 mm) and not more than
1 in (25.4 mm) from the plan thickness, one additional core shall be
taken at random from each sublot within the lot. The thickness of these
additional cores shall be determined as indicated in paragraph
304-6.1.2. A new lot average thickness shall be recomputed based on
these additional cores and the original cores taken from each sublot.
When the recomputed average lot thickness is not deficient by more than
½ in (12.5 mm) from the plan thickness, full payment shall be made. If
the average lot thickness is deficient by more than ½ in (12.5 mm) from
the plan thickness, the entire lot shall be removed and replaced at the
Contractor\'s expense or shall be permitted to remain in place at an
adjusted payment of 75 percent of the contract unit price.

When the measured thickness is more than that indicated on the plans, it
will be considered as conforming to the requirements, provided the
surface of the completed econocrete layer is within the established
grade and surface tolerance requirements.

*306-6.2.3 Grade Requirements*. When the completed surface is more than
½ in (12.5 mm) above the grade shown in the plans, the surface shall be
trimmed at the Contractor's expense using an approved grinding machine
to an elevation that falls within a tolerance of ¼ in (6 mm). The ground
surface shall be sprayed with curing compound at double the rate
specified prior to paving.

*306-6.2.4 Surface Tolerance Requirements*. Surface deviations shall not
exceed ⅜ in (9.5 mm) from a 16-ft (4.9-m) straightedge laid in any
location parallel with or at right angles to the longitudinal axis of
the centerline (includes along all edges of the paving lane). Any high
spots of more than ⅜ in (9.5 mm) in 16 ft (4.9 m) shall be marked and
immediately trimmed with an approved grinding machine. If the overlying
layer is PCC pavement, the ground surface shall be sprayed with a double
application of the curing compound at the specified rate prior to
paving.

# METHOD OF MEASUREMENT

306-7.1 The quantity of econocrete to be paid for will be determined by
the number of \[yd^2^ (m^2^)\] of econocrete actually constructed and
accepted by the Engineer as complying with the plans and specifications.

# BASIS OF PAYMENT

306-8.1 The accepted quantities of econocrete will be paid for at the
contract unit price per \[yd^2^ (m^2^)\] for econocrete base. The price
and payment shall be full compensation for furnishing and placing all
materials, provided; however, for any pavement found deficient in
thickness as specified in paragraph 306-6.2.2, the reduced unit price
shall be paid.

Payment will be made for econocrete base course\--per \[yd^2^ (m^2^)\].

# TESTING REQUIREMENTS

ASTM C 31 Making and Curing Concrete Test Specimens in the Field

ASTM C 39 Compressive Strength of Cylindrical Concrete Specimens

ASTM C 136 Sieve or Screen Analysis of Fine and Course Aggregates

ASTM C 172 Sampling Freshly Mixed Concrete

ASTM C 173 Air Content of Freshly Mixed Concrete by the Volumetric
Method

ASTM C 174 Measuring Length of Drilled Concrete Cores

ASTM C 192 Making and Curing Concrete Test Specimens in the Laboratory

ASTM C 231 Air Content of Freshly Mixed Concrete by the Pressure Method

ASTM C 1260 Standard Test Method for Potential Alkali Reactivity of
Aggregates (Mortar Bar Method)

ASTM D 560 Standard Test Methods for Freezing and Thawing Compacted
Soil-Cement Mixtures

ASTM D 3665 Random Sampling of Paving Materials

AASHTO T 26 Quality of Water to be Used in Concrete

# MATERIAL REQUIREMENTS

ASTM C 33 Specification for Concrete Aggregates

ASTM C 94 Specification for Ready-Mixed Concrete

ASTM C 150 Specification for Portland Cement

ASTM C 260 Specification for Air-Entraining Admixtures for Concrete

ASTM C 309 Specification for Liquid Membrane-Forming Compounds for

Curing Concrete

ASTM C 494 Specification for Chemical Admixtures for Concrete

ASTM C 595 Standard Specification for Blended Hydraulic Cements

ASTM C 618 Specification for Fly Ash and Raw and Calcined Natural
Pozzolans

for Use in Portland Cement Concrete

# 

ASTM C 989 Standard Specification for Ground Granulated Blast-Furnace
Slag for Use in Concrete and Mortars

Appendix C

FINAL Draft OF Item P-ATPB

Asphalt-Treated Permeable

Base Course

# DESCRIPTION

ATPB-1.1 This item shall consist of an asphalt-treated permeable base
(ATPB) course drainage layer composed of mineral aggregate and asphalt
cement, mixed in a central mixing plant and placed on a prepared surface
in accordance with these specifications, and conforming to the lines,
grades, dimensions, and typical cross-sections shown on the plans.

# MATERIALS

ATPB-2.1 AGGREGATE. The aggregate shall consist of clean, sound, hard,
durable, angular particles of crushed stone. The aggregate shall be free
from clay balls, organic matter, and other deleterious substances in
accordance with ASTM C 33.

The crushed aggregate portion retained on the ⅜-in (9.5-mm) sieve shall
contain not more than 10 percent by weight of flat or elongated pieces,
as defined in ASTM D 693, and shall have at least 90 percent by weight
of particles with at least two fractured faces. The area of each face
shall be equal to at least 75 percent of the smallest mid-sectional area
of the piece. When two fractured faces are contiguous, the angle between
the planes of fractures shall be at least 30 degrees to count as two
fractured faces.

The percentage of wear of the crushed aggregate retained on the No. 4
(4.75-mm) sieve shall not be greater than 40 percent when tested in
accordance with ASTM C 131. The sodium sulfate soundness loss shall not
exceed 10 percent, or the magnesium sulfate soundness loss shall not
exceed 13 percent, after five cycles, when tested in accordance with
ASTM C 88.

The aggregate gradation for the ATPB mixture shall be one of the
gradations selected from Table 1. Gradation shall be determined in
accordance with ASTM C 117 and C 136. The aggregate shall be
continuously well graded from coarse to fine within the limits
designated in the table and shall not vary from the low limit on one
sieve to the high limit on an adjacent sieve or vice versa.

Table 1. Aggregate gradation for job mix.

+--------------+-----------------+-----------------+-----------------+
| **Sieve      | **Percentage by |                 |                 |
| Size**       | Weight Passing  |                 |                 |
|              | Sieves**        |                 |                 |
+--------------+-----------------+-----------------+-----------------+
|              | **Gradation A** | **Gradation B** | **Gradation C** |
|              |                 |                 |                 |
|              | **(¾ in \[19    | **(1 in \[25    | **(1½ in \[38   |
|              | mm\] max.)**    | mm\] max.)**    | mm\] max.)**    |
+--------------+-----------------+-----------------+-----------------+
| 1½ in (38    |                 |                 | 95 - 100        |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| 1 in (25 mm) |                 | 95 - 100        | 72 - 82         |
+--------------+-----------------+-----------------+-----------------+
| ¾ in (19 mm) | 95 -- 100       | 77 - 87         | 60 - 70         |
+--------------+-----------------+-----------------+-----------------+
| ½ in (13 mm) | 67 -- 77        | 53 - 63         | 40 - 50         |
+--------------+-----------------+-----------------+-----------------+
| ⅜ in (9.5    | 50 -- 60        | 41 - 51         | 30 - 40         |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| No. 4 (4.75  | 19 -- 29        | 15 - 25         | 10 - 20         |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| No. 8 (2.36  | 0 -- 6          | 0 - 6           | 0 - 6           |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+

ATPB-2.2 ASPHALT CEMENT. Asphalt cement binder shall conform to the
following requirements: \[ \].

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer shall specify the grade and appropriate specifications of
> asphalt cement, based on geographical location and climatic
> conditions. The same asphalt grade as is used for P-401 material for
> the project location or a stiffer grade is deemed adequate.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

The asphalt binder content shall be between 2.0 and 3.5 percent, by
weight of the total mixture.

ATPB-2.3 ANTI-STRIPPING AGENT. An anti-stripping agent in the form of
lime shall be used to prevent stripping of the asphalt cement,
particularly if the coarse aggregate is not limestone or dolomite. Lime
shall be added at the rate of 0.5 to 1.0 percent by weight.

ATPB-2.4 SEPARATION LAYER. A separation layer consisting of
\[dense-graded aggregate meeting the gradation in Table 2\] \[geotextile
meeting AASHTO M 288 Survivability Class 2 (woven or non-woven
fabrics)\] shall be placed over the prepared subgrade prior to placing
any ATPB. The separation layer shall be checked and accepted in advance
of spreading the ATPB.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The separation layer is situated directly below the ATPB layer. Its
> main function is to keep underlying layers or subgrade soils from
> infiltrating into the ATPB. Another important function is to not allow
> infiltration of the separation layer into the ATPB or vice versa. It
> also provides a stable platform on which to build the ATPB layer.
>
> Both dense-graded aggregate layers and geotextile layers can be used
> as separation layers. Lime- or cement-treated subgrades,
> cement-treated bases, and asphalt chip seals are not acceptable as
> separation layers. The typical thickness of an aggregate separation
> layer is 4 in (102 mm). A geotextile fabric may be used in lieu of a
> dense-graded aggregate separation layer when the California bearing
> ratio (CBR) of the layer on which it will rest is greater than 6.
>
> In the first sentence of paragraph ATPB-2.4, specify the layer type of
> choice. When an aggregate separation layer is specified, insert the
> following table:
>
> Table 2. Aggregate gradation for separation layer.

  -------------------------------- --------------------------------------
  **Sieve Size**                   **Percentage by Weight Passing Sieve**

  1½ in (38 mm)                    100

  1 in (25 mm)                     95 -- 100

  ¾ in (19 mm)                     70 -- 95

  No. 4 (4.75 mm)                  55 -- 85

  No. 8 (2.36 mm)                  30 -- 60

  No. 30 (600 μm)                  12 -- 30

  No. 200 (75 μm)                  0 -- 8
  -------------------------------- --------------------------------------

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

ATPB-2.5 CHOKE STONE. If used, the choke stone material shall conform to
the requirements of the new FAA specification on choke stone.

# COMPOSITION OF MIXTURE

ATPB-3.1 GENERAL. The ATPB material shall be composed of a mixture of
aggregate, asphalt cement, and anti-stripping agent.

ATPB-3.2 MIX DESIGN. The job mix formula (JMF) shall establish a single
percentage of dry weight of aggregate passing each required sieve size,
a single percentage of asphalt cement to be added to the aggregate based
on the weight of the total mix, and a single temperature for the mixture
as it is discharged into the hauling units. When tested in accordance
with ASTM C 136, the combined aggregate shall be of such size that the
percentage composition by weight, as determined by laboratory sieves,
will conform to the gradation specified in Table 1. The gradation band
shown in Table 1 shall be applied to the JMF and used for job control.

When the component aggregates are blended together, mixed with the
specified amount of asphalt cement at a temperature of 250°F (121°C),
and compacted at 150°F (65°C) with 35 blows of a standard Marshall
hammer, the JMF shall have a permeability of not less than 500 ft/day
(152.5 m/day) nor more than 1,500 ft/day (457.5 m/day) when tested in
accordance with ASTM D 2434/AASHTO T 215 (Constant Head Permeability
Test). The JMF shall have a minimum asphalt binder content of 2.0
percent by weight, which can be adjusted upward to 3.5 percent to
provide stability under rollers during construction and to meet the
desired permeability requirements.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The typical amount of asphalt used in ATPB mixtures is between 2.0 and
> 3.5 percent by weight. Higher mixing temperatures may be required when
> modified asphalts are used.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

The JMF shall be in effect until modifications are reviewed by the
Engineer. When unsatisfactory results for any specified characteristic
of the work make it necessary, the Contractor may establish a new JMF.

ATPB-3.3 SUBMITTALS. At least \[ \] days prior to the placement of the
ATPB, the Contractor shall submit certified test reports to the Engineer
for those materials proposed for use during construction, as well as the
mix design information for the ATPB material. The certification shall
show the appropriate ASTM or AASHTO specifications or tests for the
material, the name of the company performing the tests, the date of the
tests, the test results, and a statement that the material did or did
not comply with the applicable specifications. The submittal package
shall include the following:

a.  Sources of materials, including all aggregates, asphalt cement,
    anti-stripping agent (if required), and geotextile materials (if
    selected for the separation layer).

b.  Physical properties of the aggregates, asphalt cement,
    anti-stripping agent (if required), and geotextile materials (if
    selected for the separation layer).

c.  Mixing temperature.

d.  Temperature of mix at time of discharge from mixer.

e.  JMF.

-   mix identification number.

-   percent passing each sieve size for total combined gradation,
    individual gradation of all aggregate stockpiles, and percent by
    weight of each stockpile used in the JMF.

-   asphalt grade and content.

f.  Laboratory test results.

-   permeability testing procedure.

-   permeability.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Insert the appropriate number of days for Contractor submittal of the
> certified test reports and JMF; 15 to 30 days is typical.

\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

Tests older than 6 months shall not be used. Submittals shall comply
with procedures set forth in the "Shop Drawing and Sample Submittals"
section of the General Conditions. No ATPB material shall be placed
until the submittal is accepted in writing by the Engineer and returned
to the Contractor.

# EQUIPMENT 

All equipment necessary to mix, transport, place, compact, and finish
the ATPB material shall be furnished by the Contractor and approved by
the Engineer. The equipment shall be at the job site prior to the start
of construction operations for examination by the Engineer.

ATPB-4.1 MIXING. Plants used for the preparation of the ATPB material
can be either batch plant or continuous mix type and shall conform to
the requirements of ASTM D 995, with the following changes:

-   Truck Scales---The ATPB material shall be weighed on approved scales
    furnished by the Contractor, or on public scales at the
    Contractor\'s expense. Such scales shall be inspected and sealed as
    often as the Engineer deems necessary to assure their accuracy.
    Scales shall conform to the requirements of Section 90 of the
    General Provisions.

-   Testing Laboratory---All quality control and acceptance testing
    shall be in accordance with Section 100 of the General Provisions.

-   Inspection of Plant---The Engineer shall have access, at all times,
    to all parts of the plant for checking adequacy of equipment;
    inspection operation of the plant; verifying weights, proportions,
    and character of materials; and checking the temperatures maintained
    in the preparation of the mixtures.

-   Storage Bins and Surge Bins---Use of surge bins or storage bins for
    temporary storage of hot asphalt mixtures will not be permitted.

ATPB-4.2 HAULING. Trucks used for hauling the ATPB mixture from the
plant to the job site shall have clean and smooth beds. To prevent the
mixture from adhering to them, the truck beds shall be lightly coated
with a minimum amount of concentrated hydrated lime and water solution.
The truck beds shall be raised to drain any excess solution before
loading the mixture in the trucks. Each truck shall have a suitable
cover to protect the mixture from adverse weather or long hauls.

ATPB-4.3 PLACING. The ATPB material shall be placed using an asphalt
lay-down machine. The lay-down machine shall be self-contained,
power-propelled, and equipped with an activated screed or strike-off
assembly (heated as necessary). The laydown machine shall be capable of
spreading and finishing courses of ATPB material that will meet the
specified thickness, smoothness, and grade. An alternative method for
placement that provides compaction of the ATPB material is with a large
asphalt paving machine with dual tamping bars.

The paver shall have a receiving hopper of sufficient capacity to permit
a uniform spreading operation. The hopper shall be equipped with a
distribution system to place the mixture uniformly in front of the
screed without segregation. The screed shall effectively produce a
finished surface of the required evenness and texture without tearing,
shoving, or gouging the mixture.

If an automatic grade control device is used, the paver shall be
equipped with a control system capable of automatically maintaining the
screed elevation as specified herein. The control system shall be
automatically actuated from either a reference line or a surface through
a system of mechanical sensors or sensor-directed mechanisms or devices
which will maintain the paver screed at a predetermined transverse slope
and at the proper elevation to obtain the required surface. The
transverse slope controller shall be capable of maintaining the screed
at the desired slope within plus or minus 0.1 percent. The controls
shall be capable of working in conjunction with any of the following
attachments:

a.  Ski-type device of not less than 30 ft (9.15 m) in length.

b.  Taut stringline (wire) set to grade.

c.  Short ski or shoe.

d.  Laser control.

If, during construction, it is found that the spreading and finishing
equipment causes unacceptable displacement of the ATPB surface, the use
of such equipment shall be discontinued and satisfactory equipment shall
be provided by the Contractor.

ATPB-4.4 COMPACTION. A minimum of one self-propelled steel-wheel static
roller with weight between 6 and 12 tons (5.4 and 10.9 metric tons)
shall be used to compact the ATPB. The roller shall be in good condition
and shall be capable of reversing without backlash and of compacting the
CTPB without undue displacement or excessive crushing of the aggregate.
The wheels shall be equipped with adjustable scrapers, water tanks, and
sprinkling apparatuses to prevent the ATPB mixture from sticking to the
wheels.

# 

# CONSTRUCTION METHODS

ATPB-5.1 TEST SECTION. Prior to the start of full-scale production, the
Contractor shall construct a test section to demonstrate the
constructability (including mixing, transporting, placing, and
compacting procedures) of the ATPB.

The Contractor shall prepare the ATPB mixture according to the JMF and
place it in a test section to the depth specified on the plans. The test
section shall be a minimum length representing at least 1 hour of
production or 500 ft (152.5 m), whichever is more restrictive, and of
the expected placement width, and shall consist of two side-by-side
lanes parted by a construction joint. The equipment to be used in
construction of the test section shall be the same type and weight to be
used on the remainder of the course represented by the test section.

*ATPB-5.1.1 Compaction*. The Contractor shall statically compact the
material by a minimum of two passes with the selected steel-wheel
roller. Compaction shall continue until the aggregate is properly seated
and the mixture appears stable under construction traffic.

*ATPB-5.1.2 Evaluation of Test Section*. The completed ATPB layer shall
be considered acceptable when:

-   The aggregate particles are completely coated with asphalt.

-   The rolling procedure is deemed adequate when the surface becomes
    firm and unyielding, and there is no evidence of crushing of
    aggregate, such that the ATPB layer is stable under construction
    traffic.

-   The texture of the ATPB layer looks reasonably open and water poured
    from a 1-gal (3.8-L) container flows through the layer within 1
    minute.

-   The density of core samples taken from the test section show 100
    percent of the density of laboratory-compacted specimens. If the
    density is not achieved, additional test sections are required to
    establish the necessary roller weight and rolling pattern.

If the test section should prove to be unsatisfactory to the Engineer,
the necessary adjustments to the mix design, plant operation, and/or
rolling procedures shall be made.

Test sections that do not conform to specification requirement shall be
removed and replaced at the Contractor's expense. Additional sections,
as required, shall be constructed and evaluated for conformance to the
specifications. Full production shall not begin until a successful test
section is completed.

ATPB-5.2 WEATHER LIMITATIONS. The ATPB material shall be constructed
only on a dry surface when the air temperature is 40°F (4°C) and rising
and under calm wind conditions. The ATPB shall not be placed when
rainfall is occurring or when rain is imminent. If a rain event begins
to occur immediately after placement, the layer should be compacted as
quickly as possible.

ATPB-5.3 SEPARATION LAYER. Prior to the placement of the separation
layer, the underlying layer shall be checked and accepted by the
Engineer. The underlying layer should be constructed to the grades and
elevations specified in the plans and should be free of any ruts,
depressions, or bumps.

*ATPB-5.3.1 Aggregate Separation Layer*. If an aggregate-type separation
layer is used, it shall be uniformly spread over the subgrade and
compacted.

*ATPB-5.3.2 Geotextile Separation Layer*. If a geotextile-type
separation layer is used, the geotextile fabric shall be placed in such
a manner as to avoid wrinkles. If the geotextile layer is damaged prior
to the placement of the ATPB layer, that section of the geotextile shall
be patched or replaced immediately. The fabric shall not be stretched so
tight that it will tear as the aggregate is being placed over it.
Whenever more than one section is being used, the fabric must be
overlapped based on the manufacturer's recommendations.

ATPB-5.4 MIXING. The aggregate for the ATPB mixture shall be dried and
heated prior to mixing with asphalt such that the combined aggregate
moisture content (weighted according to the composition of the blend) is
less than 0.25 percent for aggregate blends with water absorption of 2.5
percent or less, and less than 0.50 percent for aggregate blends with
water absorption greater than 2.5 percent. Water absorption of
aggregates shall be determined by ASTM C 127 and C 128. The water
content test will be conducted in accordance with ASTM C 566.

At the time of mixing, the temperature of the aggregate shall be within
the range specified in the JMF. The maximum temperature and rate of
heating shall be such that no damage occurs to the aggregates.

The dried aggregates shall be combined in the mixer to meet the
gradation requirements for the mix design. The asphalt cement shall be
weighed or metered and introduced into the mixer in the amount specified
by the JMF. The combined materials shall be mixed until the aggregate
obtains a uniform coating of asphalt binder and is thoroughly
distributed throughout the mixture.

The temperature at the discharge from the plant or surge and storage
bins shall be maintained between 275 and 325°F (135 and 163°C).

ATPB-5.5 HAULING. The ATPB mixture shall be transported to the job site
and delivered to the asphalt paver for placement. Hauling over freshly
placed material shall not be permitted until the material has been
compacted, as specified, and allowed to cool to atmospheric temperature.
Any truck causing excessive segregation of the ATPB mixture by its
suspension or other contributing factors, or that leaks or causes
delays, shall be removed from the work until such conditions are
corrected.

Loads shall not be sent out so late in the day as to prevent completion
of the spreading and compaction of the mixture during daylight, unless
sufficient artificial light is provided.

Plant production and the number of trucks used for transportation shall
be such as to ensure delivery of the mixture in sufficient quantities
and at such intervals to permit continuous placement of the material
with minimal stopping and starting of the paving operation. Failure to
maintain such delivery shall be cause to suspend the work.

ATPB-5.6 PLACING. The ATPB shall be spread at a temperature between 200
and 250°F (93 and 121°C), as measured in the hopper of the paving
machine.

The ATPB material shall be placed to the full width by the asphalt paver
in a uniform layer of such depth that, when compacted, it is of the
required thickness and conforms to the grade and contour indicated.

The speed of the paver shall be regulated to eliminate pulling and
tearing of the ATPB mat. The Contractor may install the ATPB layer in a
single or multiple compacted lifts; however, each compacted lift must be
at least 4 in (102 mm) thick and no greater than 6 in (152 mm) thick. If
multiple lifts are used, the longitudinal joint in one lift shall offset
the longitudinal joint in the lift immediately below by at least 1 ft
(0.3 m); however, the joint in the surface lift shall be at the
centerline of crowned pavements. Transverse joints in one lift shall be
offset by at least 2 ft (0.6 m) from transverse joints in the previous
lift. Transverse joints in adjacent strips shall be offset a minimum of
10 ft (3.1 m).

In placing adjacent strips of ATPB, the screed of the paving machine
shall overlap the previously placed strip 3 to 4 in (76 to 102 mm) and
shall be sufficiently high so that compaction will produce a smooth,
dense joint. The ATPB material placed on the edge of the previously
placed strip by the paver shall be pushed back to the edge of the strip
being placed. Excess material shall be removed and wasted.

In areas where machine spreading is impractical, the ATPB material shall
be spread using hand tools. The material shall be spread uniformly in a
loose layer to prevent segregation. The material shall conform to the
required grade and thickness after compaction.

ATPB-5.7 COMPACTION. Compaction of the ATPB material should begin when
the temperature of the mix has cooled to 150°F (65°C) and should be
completed before the temperature falls below 100°F (38°C). The ATPB
material shall be compacted using the approved compaction equipment and
roller pattern/sequence as determined in the test section. Sufficient
rollers shall be furnished to handle the output of the plant and each
roller shall operate at a speed no greater than 1.5 mi/hr (2.4 km/hr).

If the designated rolling pattern/sequence deviates from that approved
in the test section, or if crushing of the aggregate is observed, work
shall be stopped until the cause(s) can be determined and corrections
are made. Core samples shall then be taken to determine if adequate
density is being achieved and satisfactory permeability is being
obtained.

In all places not accessible to the rollers, the ATPB material shall be
compacted with approved mechanical hand-operated tampers.

ATPB-5.8 JOINTS. The formation of longitudinal joints shall be made in
such a manner as to ensure a continuous bond between adjacent lanes of
ATPB. All joints shall exhibit the same texture, density, and smoothness
as other portions of the layer.

The roller shall not pass over the unprotected end of the freshly laid
mixture except when necessary to form a transverse joint. When necessary
to form a transverse joint, it shall be made by means of placing a
bulkhead or by tapering the ATPB material, in which case the edge shall
be cut back to its full depth and width on a straight line to expose
vertical face. In both methods, all contact surfaces shall be given a
tack coat of asphalt material before placing any fresh mixture against
the joint. Longitudinal joints which are irregular, damaged, or
otherwise defective shall be cut back to expose a clean, sound surface
for the full depth of the course. All contact surfaces shall be given a
tack coat of asphalt material prior to placing any fresh ATPB mixture
against the joint.

ATPB-5.9 PROTECTION. The ATPB shall be maintained and protected during
their construction and until the Contractor has entirely covered the
material with pavement or the next layer. The Contractor shall maintain
drainage at the job site, such that fine material is not allowed to wash
into and clog the ATPB. In no case shall any construction traffic be
allowed on the completed ATPB until the compacted mixture has reached
ambient temperature. Only equipment necessary for the construction of
the next higher pavement layer shall be allowed on the completed ATPB.

# MATERIAL ACCEPTANCE

ATPB-6.1 ACCEPTANCE SAMPLING AND TESTING. Unless otherwise specified,
all acceptance sampling and testing necessary to determine conformance
with the requirements specified in this section will be performed by the
Engineer at no cost to the Contractor. Testing organizations performing
these tests shall meet the requirements of ASTM D 3666. All equipment in
Contractor-furnished laboratories shall be calibrated by the testing
organization prior to the start of operations.

Aggregate samples shall be furnished by the Contractor in accordance
with ASTM D 75 for laboratory testing prior to the start of production.
Additionally, the Contractor shall furnish aggregate samples at
specified intervals during production. Sampling for gradation shall be
in accordance with ASTM D 75, and testing shall be in accordance with
ASTM C 136 and C 117.

Samples of the ATPB mixture shall be taken at the point of discharge in
hauling units and tested to control uniformity in the asphalt content
and gradation. Samples shall be taken in accordance with ASTM D 979.
Enough mixture shall be taken to prepare duplicate tests on each sample
of mixture in accordance with ASTM D 2172. Samples shall be taken at
least once for any central plant-run of more than 30 minutes and at
least twice for any central plant-run of more than 5 hours. Field
samples will also be extracted and gradation checked for secondary
control.

Should gradation analysis or asphalt binder content fail to meet the
tolerances of the JMF, the Engineer may (a) order another analysis in
addition to the two analyses required each day to confirm the results of
the previous tests, or (b) instruct the Contractor to cease plant
production until such out-of-tolerance conditions have been corrected or
the permeability and density of the compacted ATPB are checked to verify
that they meet or exceed the test section values.

Completed ATPB layers shall be determined as \"unacceptable\" on the
basis of visual inspection. The Engineer shall immediately notify the
Contractor of visual defects such as non-uniform texture, evidence of
material segregation, bleeding of asphalt material, cracking and shoving
of the mixture, surface irregularities, and evidence of aggregate
crushing during the roller operations.

\"Unacceptable\" ATPB shall be removed down to the surface of the
separation layer, leaving a vertical face at the adjacent ATPB. The
separation layer shall be re-worked or cleaned, as necessary, and a tack
coat applied prior to replacing the removed ATPB material. All work
shall be at the Contractor\'s expense. Unacceptable ATPB shall not be
measured for payment.

The ATPB layer shall be tested for thickness, grade, and surface
tolerance on a lot basis, with a lot consisting of one of the following:

-   One day's production not to exceed 2,000 yd^2^ (1,675 m^2^).

-   A half day's production, where a day's production is expected to
    consist of between 2,000 and 4,000 yd^2^ (1,675 and 3,350 m^2^).

Each lot will be divided into four equal sublots. However, in the event
that three (3) sublots are produced due to circumstances significantly
affecting the paving operation, the three sublots shall constitute a
complete lot. If one (1) or two (2) sublots are produced for the same
reason, they shall be incorporated into the next lot, and the total
number of sublots shall be used in the acceptance plan calculation.

End-of-production sublots (i.e., sublots associated with the final
placement of ATPB for the project) shall be structured as follows:

-   Three (3) sublots shall constitute a lot.

-   One (1) or (2) sublots shall be incorporated into the previous lot,
    and the total number of sublots for that lot shall be used in the
    acceptance plan calculation.

*ATPB-6.1.1 Thickness Testing*. Upon completion of the ATPB layer, one
(1) 4-in (102-mm) diameter core per sublot shall be obtained from a
random location, as identified using the procedures contained in ASTM D
3665. The resulting core holes shall be filled by the Contractor with a
cold-mix asphalt or other material as approved by the Engineer.

The thickness of each core sample shall be determined using the caliper
measurement procedures provided by ASTM C 174. The average thickness for
the lot shall be determined using the individual sublot core
thicknesses. Acceptance criteria for ATPB thickness are provided in
paragraph ATPB-6.2.1.

*ATPB-6.1.2 Grade Testing*. The elevations of the finished ATPB layer
shall be surveyed on both sides of the ATPB lane, every 25 ft (7.6 m).
Acceptance criteria for ATPB grade are provided in paragraph ATPB-6.2.2.

*ATPB-6.1.3 Surface Tolerance Testing*. After completion of the final
rolling, the finished surface shall be tested with a 16-ft (4.9-m)
straightedge. The straightedge shall be applied parallel with and at
right angles to the centerline of the ATPB area, and shall be advanced
approximately one-half its length in the line of measurement. Acceptance
criteria for ATPB surface tolerance are provided in paragraph 306-6.2.3.

ATPB-6.2 ACCEPTANCE CRITERIA. Acceptance of ATPB will be based on
thickness, grade, and surface evenness, as described in the paragraphs
below.

*ATPB-6.2.1 Thickness Requirements*.

When the average measured thickness from a lot is not deficient by more
than 1 in (25 mm) from the plan thickness, full payment shall be made.
When such measurement is deficient by more than 1 in (25.4 mm) from the
plan thickness, the entire lot shall be removed by excavating to the
required depth and replacing with new material to obtain a compacted
lift thickness, at the Contractor's expense. When the measured thickness
is more than indicated, it shall be considered as conforming to the
requirements, provided the surface of the ATPB drainage layer is within
the established grade and surface tolerance requirements.

*ATPB-6.2.2 Grade Requirements*. Areas in the ATPB more than ⅝ in (16
mm) below grade shown on the plans shall be corrected at the
Contractor\'s expense by removing the defective work and replacing it
with new material; areas higher that ⅝ in (16 mm) may be cut to grade by
grinding.

*ATPB-6.2.3 Surface Tolerance Requirements*. The finished ATPB surface
shall not vary more than ½ in (12.5 mm) when tested with a 16-ft (4.9-m)
straightedge applied parallel with, or at right angles to, the
centerline of the ATPB area. Areas of the ATPB exceeding the specified
tolerances shall be corrected at the Contractor\'s expense by grinding
or by removing the defective work and replacing it with new material.

# METHOD OF MEASUREMENT

ATPB-7.1 ASPHALT-TREATED PERMEABLE BASE COURSE. Payment for ATPB course
will be based the number of \[tons (metric tons)\] of ATPB actually
constructed and accepted by the Engineer as complying with the plans and
specifications.

# BASIS OF PAYMENT

ATPB-8.1 ASPHALT-TREATED PERMEABLE BASE COURSE. Payment shall be made at
the contract unit price per \[tons (metric tons)\] for ATPB at the
specified thickness. This price shall be full compensation for
furnishing all materials; for all preparation and storage of materials;
for mixing, hauling, placing, and compacting the mixture (including the
test section); and for all labor, equipment, tools, and incidentals
necessary to complete the item.

Payment will be made for asphalt-treated permeable base course---per
\[ton (metric ton)\].

# TESTING REQUIREMENTS

ASTM C 88 Soundness of Aggregates by Use of Sodium Sulfate or Magnesium

Sulfate

ASTM C 117 Materials Finer than 75-µm (No. 200) Sieve in Mineral
Aggregates

> by Washing

ASTM C 127 Density, Relative Density (Specific Gravity), and Absorption

of Coarse Aggregate

ASTM C 128 Density, Relative Density (Specific Gravity), and Absorption

of Fine Aggregate

ASTM C 131 Resistance to Degradation of Small-Size Coarse Aggregate by
Abrasion

> and Impact in the Los Angeles Machine

ASTM C 136 Sieve or Screen Analysis of Fine and Course Aggregates

ASTM C 174 Measuring Length of Drilled Concrete Cores

ASTM C 566 Total Evaporable Moisture Content of Aggregate by Drying

ASTM D 75 Sampling Aggregates

ASTM D 693 Crushed Stone, Crushed Slag, and Crushed Gravel for Dry or

> Water-Bound Macadam Base Courses and Bituminous Macadam Base
>
> and Surface Courses of Pavements

ASTM D 979 Sampling Bituminous Paving Mixtures

ASTM D 2172 Quantitative Extraction of Bitumen From Bituminous Paving

Mixtures

ASTM D 2434/ Constant Head Permeability

AASHTO T 215

ASTM D 3665 Random Sampling of Paving Materials

ASTM D 3666 Minimum Minimum Requirements for Agencies Testing and
Inspecting

Road and Paving Materials

**MATERIAL REQUIREMENTS**

ASTM C 33 Specification for Concrete Aggregates

ASTM D 995 Mixing Plants for Hot-Mixed, Hot-Laid Bituminous Paving

Mixtures

AASHTO M 288 Geotextile Specification for Highway Applications

Appendix D

FINAL Draft OF Item P-CTPB

Cement-Treated Permeable

Base Course

# DESCRIPTION

CTPB-1.1 This item shall consist of a cement-treated permeable base
(CTPB) course composed of mineral aggregate and cement, uniformly
blended and mixed with water. The mixed material shall be spread,
shaped, and compacted in accordance with these specifications and in
conformity to the lines, grades, dimensions, and typical cross sections
shown on the plans.

# MATERIALS

CTPB-2.1 AGGREGATE. The method used in producing the aggregate shall be
such that the finished product is as consistent as practicable. The
aggregate shall consist of clean, sound, hard, durable, angular
particles of crushed stone that meets the specification requirements.
The aggregate shall be free from clay balls, organic matter, and other
deleterious substances in accordance with ASTM C 33.

The aggregate shall contain not more than 15 percent, by weight, of flat
or elongated pieces, as defined in ASTM D 693. The percentage of wear of
the crushed aggregate retained on the No. 4 (4.75-mm) sieve shall not be
greater than 50 percent when tested in accordance with ASTM C 131. The
sodium sulfate soundness loss shall not exceed 10 percent, or the
magnesium sulfate soundness loss shall not exceed 13 percent, after five
cycles, when tested in accordance with ASTM C 88.

When tested in accordance with ASTM C 136, the aggregate shall conform
to the gradation shown in Table 1. The aggregate shall be continuously
well graded from coarse to fine within the limits designated in the
table and the gradation shall not vary from the low limit on one sieve
to the high limit on an adjacent sieve or vice versa.

Table 1. Aggregate gradation for CTPB material.

+--------------+-----------------+-----------------+-----------------+
| **Sieve      | **Percentage by |                 |                 |
| Size**       | Weight Passing  |                 |                 |
|              | Sieves**        |                 |                 |
+--------------+-----------------+-----------------+-----------------+
|              | **Gradation A** | **Gradation B** | **Gradation C** |
|              |                 |                 |                 |
|              | **(¾ in \[19    | **(1 in \[25    | **(1½ in \[38   |
|              | mm\] max.)**    | mm\] max.)**    | mm\] max.)**    |
+--------------+-----------------+-----------------+-----------------+
| 1½ in (38    |                 |                 | 95 - 100        |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| 1 in (25 mm) |                 | 95 - 100        | 72 - 82         |
+--------------+-----------------+-----------------+-----------------+
| ¾ in (19 mm) | 95 - 100        | 77 - 87         | 60 - 70         |
+--------------+-----------------+-----------------+-----------------+
| ½ in (13 mm) | 67 - 77         | 53 - 63         | 40 - 50         |
+--------------+-----------------+-----------------+-----------------+
| ⅜ in (9.5    | 50 - 60         | 41 - 51         | 30 - 40         |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| No. 4 (4.75  | 19 - 29         | 15 - 25         | 10 - 20         |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+
| No. 8 (2.36  | 0 - 6           | 0 - 2           | 0 - 6           |
| mm)          |                 |                 |                 |
+--------------+-----------------+-----------------+-----------------+

CTPB-2.2 CEMENT. Cement shall conform to the requirements of ASTM \[ \].

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The Engineer shall specify ASTM C 150 Type I, II, III, IV, or V or
> ASTM C 595 Type IS, IS-A, IP, IP-A, P, or PA.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

CTPB-2.3 WATER. Water used in mixing or curing shall be clean and free
of oil, salt, acid, alkali, sugar, vegetable, or other substances
injurious to the finished product. In addition, water shall conform to
requirements of AASHTO T 26. Water known to be of potable quality may be
used without testing.

CTPB-2.4 SEPARATION LAYER. A separation layer consisting of
\[dense-graded aggregate meeting the gradation in Table 2\] \[geotextile
meeting AASHTO M 288 Survivability Class 2 (woven or non-woven
fabrics)\] shall be placed over the prepared subgrade prior to placement
of any CTPB material. The separation layer shall be checked and accepted
in advance of spreading the CTPB.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> The separation layer is situated directly below the CTPB layer. Its
> main function is to keep underlying layers or subgrade soils from
> infiltrating into the CTPB. Another important function is to not allow
> infiltration of the separation layer into the CTPB or vice versa. It
> also provides a stable platform on which to build the CTPB layer.
>
> Both dense-graded aggregate layers and geotextile layers can be used
> as separation layers. Lime- or cement-treated subgrades,
> cement-treated bases, and asphalt chip seals are not acceptable as
> separation layers. The typical thickness of an aggregate separation
> layer is 4 in (102 mm). A geotextile fabric may be used in lieu of a
> dense-graded aggregate separation layer when the California bearing
> ratio (CBR) of the layer on which it will rest is greater than 6.
>
> In the first sentence of paragraph CTPB-2.4, specify the layer type of
> choice. When an aggregate separation layer is specified, insert the
> following table:

Table 2. Aggregate gradation for separation layer.

  -------------------------------- --------------------------------------
  **Sieve Size**                   **Percentage by Weight Passing Sieve**

  1½ in (38 mm)                    100

  1 in (25 mm)                     95 - 100

  ¾ in (19 mm)                     70 - 95

  No. 4 (4.75 mm)                  55 - 85

  No. 8 (2.36 mm)                  30 - 60

  No. 30 (600 μm)                  12 - 30

  No. 200 (75 μm)                  0 - 8
  -------------------------------- --------------------------------------

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

CTPB-2.5 CHOKE STONE. Choke stone is only required when a CTPB is placed
directly beneath a portland cement concrete (PCC) surface layer. It
shall conform to the requirements of the new FAA specification for choke
stone.

# COMPOSITION OF MIXTURE

CTPB-3.1 GENERAL. The CTPB material shall be composed of a mixture of
aggregate, cement, and water.

CTPB-3.2 MIX DESIGN. The mix design shall establish the percentage of
dry weight of aggregate passing each required sieve size and the
percentage of cement based upon the weight of the total mix. The
combined aggregate shall be of such size that the percentage composition
by weight, as determined by laboratory sieves, will conform to the
gradation specified in Table 1, when tested in accordance with ASTM C
136. The gradation band shown in Table 1 shall be applied to the mix
design and should be used for job control.

The mix design shall contain at least 250 lbs (113 kg) of cement per
cubic yard and the cement paste volume shall be adequate for uniformly
coating the aggregate as determined by visual examination. The mix
design shall also have a permeability of not less than 500 ft/day (152.5
m/day) nor more than 1,500 ft/day (457.5 m/day) when tested in the
laboratory in accordance with ASTM D 2434/AASHTO T 215 (Constant Head
Permeability Test).

Should a change in aggregate sources or type of cement used be made, a
new mix design shall be submitted to the Engineer for approval.

CTPB-3.3 SUBMITTALS. At least \[ \] days prior to the placement of the
CTPB, the Contractor shall submit certified test reports to the Engineer
for those materials proposed for use during construction, as well as the
mix design information for the CTPB material. The certification shall
show the appropriate ASTM specifications or tests for the material, the
name of the company performing the tests, the date of the tests, the
test results, and a statement that the material did or did not comply
with the applicable specifications. The submittal package shall include
the following:

a.  Sources of materials, including all aggregates, cement, curing
    materials, and geotextile or aggregate separator materials (if
    used).

b.  Physical properties of the aggregates, cement, curing materials, and
    geotextile materials (if used).

c.  Mix design

-   mix identification number.

-   aggregate gradation.

-   cement type and content.

-   water content.

d.  Laboratory test results.

-   compaction procedure.

-   permeability testing procedure.

-   permeability.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Insert the appropriate number of days for Contractor submittal of the
> certified test reports and mix design; 15 to 30 days is typical.

\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

Tests older than 6 months shall not be used. Submittals shall comply
with procedures set forth in the "Shop Drawing and Sample Submittals"
section of the General Conditions. No CTPB material shall be placed
until the submittal is approved by the Engineer.

# EQUIPMENT 

All equipment necessary to mix, transport, place, compact, and finish
the CTPB material shall be furnished by the Contractor and approved by
the Engineer. The equipment will be inspected by the Engineer prior to
the start of construction operations.

CTPB-4.1 MIXING. The CTPB material may be mixed in a stationary mixer,
either at a central batch plant or at the site. Each mixer shall have
attached in a prominent place a manufacturer\'s nameplate showing the
capacity of the drum in terms of volume of mix and the speed of rotation
of the mixing drum or blades.

The batch plant and equipment shall conform to the requirements of ASTM
C 94. Free access to the plant must be provided to the Engineer at all
times for inspection of the plant's equipment and operation and for
sampling the CTPB mixture and its components.

The mixers shall be examined daily by the Contractor and periodically by
the Engineer for changes in condition due to accumulation of hard
concrete or mortar or wear of blades. The pick-up and throw-over blades
shall be replaced as necessary to provide adequate mixing.

CTPB-4.2 HAULING. The mixed CTPB material shall be transported from the
plant to the job site in trucks or other hauling equipment having beds
that are smooth and clean. Truck bed covers shall be provided to protect
the CTPB during transport from rain. CTPB material that becomes wet
during transport will be rejected.

CTPB-4.3 PLACING. The CTPB material shall be placed using a mechanical
spreader or an asphalt paver. The spreading equipment shall be capable
of placing the material, without segregation, into a uniform layer or
lift meeting the required grade and cross-section. The equipment shall
be equipped with a strike-off plate capable of being adjusted to the
specified layer thickness. It shall also be equipped with two end gates
or cut-off plates such that the CTPB may be spread in variable widths.
An alternative method for placement that provides compaction of the CTPB
material is with a large asphalt paving machine with dual tamping bars.

CTPB-4.4 COMPACTION. Compaction of the CTPB layer shall be accomplished
using a minimum of one self-propelled, steel-wheel static roller with
weight between 6 and 12 tons (5.4 to 10.9 metric tons). The roller shall
be in good condition and shall be capable of reversing without backlash
and of compacting the CTPB without undue displacement or excessive
crushing of the aggregate.

# CONSTRUCTION METHODS

CTPB-5.1 TEST SECTION. Prior to the start of full-scale production, the
Contractor shall construct a test section to demonstrate the
constructability (including mixing, transporting, placing, and
compacting procedures) of the CTPB.

The Contractor shall prepare the CTPB mixture according to the mix
design and place it in a test section to the depth specified on the
plans. The test section shall be a minimum length representing at least
1 hour of production or 500 ft (152.5 m), whichever is more restrictive
and of the expected placement width, and shall consist of two
side-by-side lanes parted by a construction joint. The equipment to be
used in construction of the test section shall be the same type and
weight to be used on the remainder of the course represented by the test
section.

*CTPB-5.1.1 Compaction*. The Contractor shall statically compact the
material by a minimum of two passes of the selected steel wheel roller.
Compaction shall continue until the aggregate is properly seated and the
mixture appears stable under construction traffic.

*CTPB-5.1.2 Evaluation of Test Section*. The completed CTPB layer shall
be considered acceptable when:

-   The aggregate particles are completely coated with cement paste.

-   The rolling procedure is deemed adequate when the surface becomes
    firm and unyielding, and there is no evidence of crushing of
    aggregate, and the compacted CTPB layer is stable under construction
    traffic.

-   The texture of the CTPB layer looks reasonably open and water poured
    from a 1-gal (3.8-L) container flows readily through the layer
    within 1 minute.

If the test section should prove to be unsatisfactory, adjustments will
be made to the mix design, plant operation, and/or rolling procedures as
necessary.

Test sections that do not conform to specification requirement shall be
removed and replaced at the Contractor's expense. Additional test
sections shall be constructed and evaluated for conformance to the
specifications. Full production shall not begin until a successful test
section is completed.

CTPB-5.2 WEATHER LIMITATIONS.

*CTPB-5.2.1 Cold Weather*. The CTPB material shall not be mixed or
placed while the air temperature is below 40°F (4°C) or when conditions
indicate that the temperature may fall below 35°F (2°C) within 24 hours.
The CTPB shall not be placed on frozen underlying courses or mixed when
aggregate is frozen.

*CTPB-5.2.2 Rain*. The CTPB may not be placed when rainfall is occurring
or where rain is imminent. Any CTPB material that has become excessively
wet by rain during transport and/or placement will be rejected.

CTPB-5.3 SEPARATION LAYER. Prior to the placement of the separation
layer, the underlying layer shall be checked and accepted by the
Engineer. The underlying layer should be constructed to the grades and
elevations specified in the plans and should be free of any ruts,
depressions, or bumps. Any ruts or soft yielding places caused by
improper drainage conditions, hauling, or any other cause, shall be
corrected before the separation layer is placed thereon.

[]{.mark}

*CTPB-5.3.1 Aggregate Separation Layer*. If an aggregate-type separation
layer is used, it shall be uniformly spread over the subgrade and
compacted.

*CTPB-5.3.2 Geotextile Separation Layer*. If a geotextile-type
separation layer is used, the geotextile fabric shall be placed in such
a manner as to avoid excessive wrinkles. If the geotextile layer gets
damaged prior to the placement of the CTPB layer, that section of the
geotextile should be patched or replaced immediately at the Contractor's
expense. The fabric shall not be stretched so tight that it will tear as
the aggregate is being placed over it. Whenever more than one section is
being used, the fabric must be overlapped based on the manufacturer's
recommendations.

CTPB-5.4 GRADE CONTROL. Grade control between the edges of the CTPB
shall be accomplished by grade stakes, steel pins, or forms placed in
lanes parallel to the centerline and at intervals of 50 ft (15.2 m) or
less on the longitudinal grade and at 25 ft (7.6 m) or less on the
transverse grade.

CTPB-5.5 MIXING. Aggregate and cement may be proportioned either by
weight or volume, and shall be mixed sufficiently to prevent the forming
of cement balls when water is added. Batching weights shall be within a
tolerance of 1 percent for cement and 2 percent for aggregates. The
mixing time shall be that which is required to secure an intimate,
uniform mixture of aggregate, cement, and water.

CTPB-5.6 HAULING. The CTPB mixture shall be transported to the job site
and delivered to the spreader for placement. The elapsed time between
the start of moist mixing and the time the CTPB is deposited in-place at
the work site shall not exceed (a) 30 minutes when the CTPB is hauled in
non-agitating trucks, or (b) 45 minutes when the CTPB is hauled in
transit mixers. Retempering the CTPB material by adding water or by
other means shall not be permitted.

[]{.mark}

CTPB-5.7 PLACING. The CTPB mixture shall be spread into a uniform layer
of such width and thickness that, following compaction, it conforms to
the required grade and cross-section. The Contractor may install the
CTPB layer in a single or multiple compacted lifts; however, each
compacted lift must be at least 4 in (102 mm) thick and no greater than
6 in (152 mm) thick. Successive lifts shall be placed and compacted so
that each successive layer is placed on the previous layer within 1
hour.

A single spreader may be used, provided it is capable of placing a
uniform, full-depth layer of material across the full width of the base
in one pass. Otherwise, two or more spreaders will be required, and
shall be operated so that spreading progresses along the full width of
the base in a uniform manner, and the placement by each of the spreaders
is no more than 1 hour apart.

CTPB-5.8 COMPACTION. Immediately upon completion of the spreading
operations, the CTPB material shall be compacted using the approved
compaction equipment and roller pattern/sequence, as determined in the
approved test section. Sufficient rollers shall be furnished to handle
the output of the plant. If the rolling pattern/sequence results in
undue displacement of the surface, or causes crushing of the aggregate,
work shall be stopped until the cause(s) can be determined and
corrections are made.

Alternative compaction using a large asphalt paving machine with dual
tamping bars may be used in lieu of the rolling.

In all places not accessible to the rollers (or the alternative paving
machine), the CTPB material shall be compacted with approved mechanical
hand-operated tampers.

Not more than 30 minutes shall elapse between the start of moist mixing
of the CTPB material and the start of field compaction. In addition,
field compaction shall be completed within 60 minutes.

CTPB-5.9 CHOKE STONE. The choke stone shall be prepared and placed in
accordance with the new FAA specification for choke stone.

CTPB-5.10 PROTECTION. Completed portions of the CTPB layer, following
placement of the choke stone, can be opened immediately to low-speed
traffic and to construction equipment, provided the CTPB is sufficiently
stable and does not ravel or loosen under such traffic. The CTPB shall
also be protected from freezing until the layer above it is placed.

# MATERIAL ACCEPTANCE

CTPB-6.1 ACCEPTANCE SAMPLING AND TESTING. Unless otherwise specified,
all acceptance sampling and testing necessary to determine conformance
with the requirements specified in this section will be performed by the
Engineer at no cost to the Contractor. Testing organizations performing
these tests shall meet the requirements of ASTM D 3666. All equipment in
Contractor-furnished laboratories shall be calibrated by the testing
organization prior to the start of operations.

Aggregate samples shall be furnished by the Contractor in accordance
with ASTM D 75 for laboratory testing prior to the start of production.
Additionally, the Contractor shall furnish aggregate samples at
specified intervals during production. Sampling for gradation shall be
in accordance with ASTM D 75 and testing shall be in accordance with
ASTM C 136 and C 117.

Completed CTPB layers shall be determined as \"unacceptable\" on the
basis of visual inspection. The Engineer shall immediately notify the
Contractor of visual defects, such as non-uniform texture, evidence of
material segregation, cracking and shoving of the mixture, surface
irregularities, and evidence of aggregate crushing during the roller
operations.

\"Unacceptable\" CTPB shall be removed down to the surface of the
separation layer, leaving a vertical face at the adjacent CTPB. The
separation layer shall be re-worked or cleaned, as necessary, prior to
replacing the removed CTPB material. All work shall be at the
Contractor\'s expense. Unacceptable CTPB shall not be measured for
payment.

The CTPB layer shall be tested for thickness, grade, and surface
tolerance on a lot basis, with a lot consisting of one of the following:

-   One day's production not to exceed 2,000 yd^2^ (1,675 m^2^).

-   A half day's production, where a day's production is expected to
    consist of between 2,000 and 4,000 yd^2^ (1,675 and 3,350 m^2^).

Each lot will be divided into four equal sublots. However, in the event
that three (3) sublots are produced due to circumstances significantly
affecting the paving operation, the three sublots shall constitute a
complete lot. If one (1) or two (2) sublots are produced for the same
reason, they shall be incorporated into the next lot, and the total
number of sublots shall be used in the acceptance plan calculation.

End-of-production sublots (i.e., sublots associated with the final
placement of CTPB for the project) shall be structured as follows:

-   Three (3) sublots shall constitute a lot.

-   One (1) or (2) sublots shall be incorporated into the previous lot,
    and the total number of sublots for that lot shall be used in the
    acceptance plan calculation.

Within each sublot, one (1) thickness measurement and continuous surface
straightedge test (for surface tolerance testing) shall be performed, as
described below.

*CTPB-6.1.1 Thickness Testing*. Thickness testing shall commence no
earlier than 3 days after placement. CTPB thickness shall be determined
by measuring the depth of core holes obtained by taking one (1) 4-in
(102-mm) diameter core per sublot. The core holes shall be obtained from
a random location, as identified using the procedures contained in ASTM
D 3665. The core holes shall be filled by the Contractor with CTPB
material or Portland cement concrete (PCC), as approved by the Engineer.
Acceptance criteria for CTPB thickness is provided in paragraph
CTPB-6.2.1.

*CTPB-6.1.2 Grade Testing*. The elevations of the finished CTPB shall be
surveyed on both sides of the CTPB lane, every 25 ft (7.6 m). Acceptance
criteria for CTPB grade are provided in paragraph CTPB-6.2.2.

*CTPB-6.1.3 Surface Tolerance Testing*. As soon as the CTPB has hardened
sufficiently, it shall be tested for surface tolerance with a 16-ft
(4.9-m) straightedge or other specified device provided by the
Contractor. The straightedge shall be applied parallel with and at right
angles to the centerline of the CTPB area, and shall be advanced
approximately one-half its length in the line of measurement. Acceptance
criteria for CTPB surface tolerance are provided in paragraph
CTPB-6.2.3.

CTPB-6.2 ACCEPTANCE CRITERIA. Acceptance of CTPB will be based on
thickness, grade, and surface tolerance, as described in the paragraphs
below.

*CTPB-6.2.1 Thickness Requirements*. When the average measured thickness
from a lot is not deficient by more than 1 in (25 mm) from the plan
thickness, full payment will be made. When such measurement is deficient
by more than 1 in (25 mm) from the plan thickness, the entire lot shall
be removed by excavating to the required depth and replaced with new
material to obtain a compacted lift thickness, at the Contractor's
expense. When the measured thickness is more than indicated, it will be
considered as conforming to the requirements provided the surface of the
CTPB drainage layer is within the established grade and surface
tolerance requirements.

*CTPB-6.2.2 Grade Requirements*. Areas in the CTPB more than ⅝ in (16
mm) below the grade shown on the plans shall be corrected at the
Contractor\'s expense by removing the defective work and replacing it
with new material. Areas more than ⅝ in (16 mm) above the grade shown on
the plans shall be removed and replaced at the Contractor's expense.

*CTPB-6.2.3 Surface Tolerance Requirements*. The finished CTPB surface
shall not vary more than ½ in (12.5 mm) when tested with a 16-ft (4.9-m)
straightedge applied parallel with, or at right angles to, the
centerline of the CTPB area. Areas of the CTPB exceeding the specified
tolerance shall be corrected at the Contractor\'s expense by removing
the defective work and replacing it with new material.

# METHOD OF MEASUREMENT

CTPB-7.1 CEMENT-TREATED PERMEABLE BASE COURSE. Payment for CTPB course
will be based on the number of \[yd^2^ (m^2^)\] of CTPB actually
constructed and accepted by the Engineer as complying with the plans and
specifications.

# BASIS OF PAYMENT

CTPB-8.1 CEMENT-TREATED PERMEABLE BASE COURSE. Payment shall be made at
the contract unit price per \[yd^2^ (m^2^)\] for CTPB at the specified
thickness. This price shall be full compensation for furnishing all
materials; for all preparation and storage of materials; for mixing,
hauling, placing, compacting, and curing the mixture (including the test
section); and for all labor, equipment, tools, and incidentals necessary
to complete the item.

Each lot of CTPB material will be accepted for thickness at the full
contract unit price when the results of core hole depth measurements
indicate that the average thickness for the lot is no more than 1 in
(25.4 mm) more or less than the plan layer thickness.

Payment will be made for cement-treated permeable base course---per
\[yd^2^ (m^2^)\].

# TESTING REQUIREMENTS

ASTM C 88 Soundness of Aggregates by Use of Sodium Sulfate or Magnesium

Sulfate

ASTM C 117 Materials Finer than 75-µm (No. 200) Sieve in Mineral
Aggregates

> by Washing

ASTM C 131 Resistance to Degradation of Small-Size Coarse Aggregate by
Abrasion

> and Impact in the Los Angeles Machine

ASTM C 136 Sieve or Screen Analysis of Fine and Course Aggregates

ASTM D 75 Sampling Aggregates

ASTM D 693 Crushed Stone, Crushed Slag, and Crushed Gravel for Dry or

> Water-Bound Macadam Base Courses and Bituminous Macadam Base
>
> and Surface Courses of Pavements

ASTM D 2434/ Constant Head Permeability

AASHTO T 215

ASTM D 3665 Random Sampling of Paving Materials

ASTM D 3666 Minimum Minimum Requirements for Agencies Testing and
Inspecting

Road and Paving Materials

AASHTO T 26 Quality of Water to be used in Concrete

**MATERIAL REQUIREMENTS**

ASTM C 33 Specification for Concrete Aggregates

ASTM C 94 Specification for Ready-Mixed Concrete

ASTM C 150 Specification for Portland Cement

ASTM C 595 Blended Hydraulic Cements

AASHTO M 288 Geotextile Specification for Highway Applications

Appendix E

Draft OF Item P-CS

CHoke Stone Interlayer

# DESCRIPTION

CS-1.1 This item shall consist of a choke stone interlayer comprised of
crushed mineral aggregate applied to the surface of a stabilized and/or
permeable base layer placed beneath Portland cement concrete (PCC)
pavement. The material shall be applied to the surface of the subject
layer in accordance with these specifications and in conformity to the
lines, grades, dimensions, and typical cross sections shown on the
plans.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> A choke stone is a small-size stone layer (generally ½ to 1 in \[12.5
> to 25 mm\] thick) used to stabilize the surface of a permeable base
> layer placed directly beneath PCC pavement and to guard against yield
> loss of the overlying PCC. Additionally, the choke stone prevents
> bonding of the PCC layer to the underlying stabilized and/or permeable
> base layer.
>
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

# MATERIALS

CS-2.1 AGGREGATE. The method used in producing the aggregate shall be
such that the finished product is as consistent as practicable. The
aggregate shall consist of clean, sound, hard, durable, angular
particles of crushed stone that meets the specification requirements.
The aggregate shall be free from clay balls, organic matter, and other
deleterious substances in accordance with ASTM C 33.

Choke stone shall be made of hard, durable, crushed aggregate having at
least 90 percent fractured faces. The aggregate shall contain not more
than 15 percent, by weight, of flat or elongated pieces, as defined in
ASTM D 693. The percentage of wear of the crushed aggregate retained on
the No. 4 (2.36-mm) sieve shall not be greater than 50 percent when
tested in accordance with ASTM C 131. The sodium sulfate soundness loss
shall not exceed 10 percent, or the magnesium sulfate soundness loss
shall not exceed 13 percent, after five cycles, when tested in
accordance with ASTM C 88.

The aggregate shall conform to the gradation shown in Table 1 or the
gradation requirements for ASTM No. 89 stone, when tested in accordance
with ASTM C 136. The aggregate shall be continuously well graded from
coarse to fine and the gradation shall not vary from the low limit on
one sieve to the high limit on an adjacent sieve or vice versa.

Table 1. Aggregate gradation for CHOKE STONE material.

  ------------------------------- ---------------------------------------
  **Sieve Size**                  **Percentage by Weight Passing Sieves**

                                  **Choke Stone**

  ½ in (13 mm)                    100

  ⅜ in (9.5 mm)                   80 - 100

  No. 4 (4.75 mm)                 10 - 100

  No. 8 (2.36 mm)                 5 - 50

  No. 16 (1.18 mm)                0 - 10
  ------------------------------- ---------------------------------------

When used on permeable base layers, the ratio of the D~15~ of the
permeable base layer to the D~15~ of the choke stone shall be less than
5. Also, the ratio of the D~50~ of the permeable base layer to the D~50~
of the choke stone shall be greater than 2.

CS-2.2 SUBMITTALS. At least \[ \] days prior to the placement of the
choke stone, the Contractor shall submit certified test reports to the
Engineer for the material proposed for use during construction. The
certification shall show the appropriate ASTM specifications or tests
for the material, the name of the company performing the tests, the date
of the tests, the test results, and a statement that the material did or
did not comply with the applicable specifications.

> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
> \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
>
> Insert the appropriate number of days for contractor submittal of the
> certified test reports, 15 to 30 days is typical.

\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*

Tests older than 6 months shall not be used. Submittals shall comply
with procedures set forth in the "Shop Drawing and Sample Submittals"
section of the General Conditions. No choke stone shall be placed until
the submittal is approved by the Engineer.

# CONSTRUCTION METHODS

CS-3.1 WEATHER LIMITATIONS. The choke stone may not be placed when
rainfall is occurring or where rain is imminent.

[]{.mark}

CS-3.2 PLACEMENT. The choke stone aggregate shall be spread into a
single uniform layer of such width and thickness that, following
compaction, it conforms to the required grade and cross-section. The
choke stone shall be placed immediately after final compaction of the
underlying stabilized and/or permeable base layer. The choke stone shall
be spread in a thin layer no thicker than ½ in (13 mm) using spreading
equipment approved by the Engineer.

CS-3.3 COMPACTION. Immediately upon completion of the spreading
operations, the choke stone material shall be compacted using two passes
of a steel-wheel roller. If the rolling pattern/sequence results in
undue displacement of the surface, or causes crushing of the aggregate,
work shall be stopped until the cause(s) can be determined and
corrections are made. Sieve testing is not required after the compaction
of the choke stone.

# MATERIAL ACCEPTANCE

CS-3.4 ACCEPTANCE SAMPLING AND TESTING. Unless otherwise specified, all
acceptance sampling and testing necessary to determine conformance with
the requirements specified in this section will be performed by the
Engineer at no cost to the Contractor. Testing organizations performing
these tests shall meet the requirements of ASTM D 3666. All equipment in
Contractor-furnished laboratories shall be calibrated by the testing
organization prior to the start of operations.

Aggregate samples shall be furnished by the Contractor in accordance
with ASTM D 75 for laboratory testing prior to the start of production.
Additionally, the Contractor shall furnish aggregate samples at
specified intervals during production. Sampling for gradation shall be
in accordance with ASTM D 75, and testing shall be in accordance with
ASTM C 136 and C 117.

CS-3.5 ACCEPTANCE CRITERIA. Completed choke stone layers shall be
determined as "acceptable" or \"unacceptable\" on the basis of visual
inspection. The Engineer shall immediately notify the Contractor of
visual defects, such as improper thickness, non-uniform texture,
evidence of material segregation, surface irregularities, and evidence
of aggregate crushing during the roller operations.

# METHOD OF MEASUREMENT

CS-4.1 Payment for choke stone course will be based on the number of
\[yd^2^ (m^2^)\] of choke stone actually constructed and accepted by the
Engineer as complying with the plans and specifications.

# BASIS OF PAYMENT

CS-5.1 Payment shall be made at the contract unit price per \[yd^2^
(m^2^)\] for choke stone at the specified thickness. This price shall be
full compensation for furnishing all materials for all preparation and
storage of materials; for blending, hauling, placing, and compacting the
mixture; and for all labor, equipment, tools, and incidentals necessary
to complete the item.

# TESTING REQUIREMENTS

ASTM C 88 Soundness of Aggregates by Use of Sodium Sulfate or Magnesium

Sulfate

ASTM C 117 Materials Finer than 75-µm (No. 200) Sieve in Mineral
Aggregates

> by Washing

ASTM C 131 Resistance to Degradation of Small-Size Coarse Aggregate by
Abrasion

> and Impact in the Los Angeles Machine

ASTM C 136 Sieve or Screen Analysis of Fine and Course Aggregates

ASTM D 75 Sampling Aggregates

ASTM D 693 Crushed Stone, Crushed Slag, and Crushed Gravel for Dry or

> Water-Bound Macadam Base Courses and Bituminous Macadam Base and
> Surface Courses of Pavements

ASTM D 3665 Random Sampling of Paving Materials

ASTM D 3666 Minimum Requirements for Agencies Testing and Inspecting

Road and Paving Materials

ASTM D 5821 Determining the Percentage of Fractured Particles in Coarse

Aggregate