# PART II -- EARTHWORK

### **ITEM P-101 SURFACE PREPARATION**

Description

**101-1.1.** This item shall consist of preparation of existing pavement
surfaces for overlay, removal of existing pavement, and other
miscellaneous items. The work shall be accomplished in accordance with
these specifica­tions and the applicable drawings.

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> **For projects that involve preparing and repairing the existing
> pavement to accommodate an overlay, add the following ITEM P-101:
> SURFACE PREPARATION.**

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Equipment

**101-2.1.** All equipment shall be specified hereinafter or as approved
by the Engineer. The equipment shall not cause damage to the pavement to
remain in place.

Construction

**101-3.1. REMOVAL OF EXISTING PAVEMENT**

**a. Concrete:** The existing concrete to be removed shall be freed from
the pavement to remain unless jackhammers are used for the complete
removal. This shall be accomplished by line drilling or sawing through
the complete depth of the slab one foot inside the perimeter of the
final removal limits or outside the load transfer devices, whichever is
greater. In this case, the limits of removal would be located on joints.
If line drilling is used, the distance between holes shall not exceed
the diameter of the hole. The pavement between the perimeter of the
pavement removal and the saw cut or line-drilled holes shall be removed
with a jackhammer. Where the perimeter of the removal limits is not
located on the joint, the perimeter shall be saw cut 2 inches in depth
or 1/4 the slab thickness, whichever is less. Again, the concrete shall
be line drilled or saw cut the full depth of the pavement 6 inches
inside the removal limits. The pavement inside the saw cut or line shall
be broken by methods suitable to the Contractor; however, if the
material is to be wasted on the airport site, it shall be reduced to a
maximum size designated by the airport owner. The Contractor\'s removal
operation shall not cause damage to cables, utility ducts, pipelines, or
drainage structures under the pavement. Any damage shall be repaired by
the Contractor at no expense to the airport owner.

**b. Asphaltic Concrete**: Asphaltic concrete pavement to be removed
shall be cut to the full depth of the bituminous material around the
perimeter of the area to be removed. The pavement shall be removed in
such a manner that the joint for each layer of pavement replacement is
offset one foot from the joint in the preceding layer. This does not
apply if the removed pavement is to be replaced with concrete or soil.
If the material is to be wasted on the airport site, it shall be broken
to a maximum size as designated by the airport owner.

**101-3.2. PREPARATION OF JOINTS AND CRACKS**. All joints and cracks in
bituminous and concrete pavements to be overlaid with asphaltic concrete
shall be cleaned of joint and crack sealer, debris, and vegetation. Any
excess joint or crack sealer on the surface of the pavement shall also
be removed from the pavement surface. If vegetation is a problem a soil
sterilant shall be applied. Cracks and joints wider than 3/8 inch shall
be filled with a mixture of emulsified asphalt and aggregate. The
aggregate shall consist of limestone, volcanic ash, sand, or other
material that will cure to form a hard substance. The combined gradation
shall be as shown in Table 1.

[TABLE 1]{.underline}

Sieve Size Percent Passing

No. 4 100

No. 8 90-100

No. 16 65-90

No. 30 40-60

No. 50 25-42

No. 100 15-30

No. 200 10-20

Up to 3% cement can be added to accelerate the set time. The mixture
shall not contain more than 20% natural sand without approval in writing
from the Engineer.

The proportions of asphalt emulsion and aggregate shall be determined in
the field and may be varied to facilitate construction requirements.
Normally, these proportions will be approxi­mately one part asphalt
emulsion to five parts aggregate by volume. The material shall be poured
into the joints or cracks or shall be placed in the joint or crack and
compacted to form a voidless mass. The joint or crack shall be filled
within 0 to 1/8 inch of the surface. Any material spilled outside the
width of the joint shall be removed from the surface prior to
constructing the overlay. Where concrete overlays are to be constructed,
only the excess joint material on the surface and vegetation in the
joints need to be removed.

**101-3.3. REMOVAL OF PAINT AND RUBBER.** All paint and rubber over one
foot wide that will affect the bond of the new overlay shall be removed
from the surface of the existing pavement. Chemicals, high-pressure
water, heater scarifier (asphaltic concrete only), cold milling, or
sandblasting may be used. Any methods used shall not cause major damage
to the pavement. Major damage is defined as changing the properties of
the pavement or removing pavement over 1/8 inch deep. If chemicals are
used, they shall comply with the state\'s environmental protection
regulations. No material shall be deposited on the runway shoulders. All
wastes shall be disposed of in areas indicated in this specification or
shown on the plans. This specification shall not be used for removal of
rubber deposits to improve skid resistance or obliterate traffic
markings where a new overlay is not to be constructed.

**101-3.4. CONCRETE SPALL OR FAILED ASPHALTIC CONCRETE PAVEMENT
REPAIR.**

**a. Repair of Concrete Spalls in Areas to be overlaid with Asphalt:**
The Contractors shall repair all spalled concrete as shown on the plans
or as directed by the Resident Engineer. The perimeter of the repair
shall be sawed a minimum of 1 inch deep or shall be cut with approved
tools to this depth. The deteriorated material shall be removed to a
depth where the existing material is firm or cannot be easily removed
with a geologist pick. The removed area shall be filled with asphaltic
concrete with a minimum Marshal stability of 1,200 lbs. and maximum flow
of 20. The material shall be compacted with equipment approved by the
Resident Engineer until the material is dense and no movement or marks
can be noted. The material shall not be placed in lifts over 4 inches in
depth. This method of repair applies only to pavement to be overlaid.

**b. Asphaltic Concrete Pavement Repair:** The failed areas shall be
removed as specified in paragraph 101-3.1b. All failed material
including surface, base course, subbase course, and subgrade shall be
removed. The base course and subbase shall be replaced if it has been
infiltrated with clay, silt, or other material affecting the
load-bearing capacity. Materials and methods of construction shall
comply with the other applicable sections of this specification.

**101-3.5: COLD PLANING.**

**a. Patching:** The machine shall be capable of cutting a vertical edge
without chipping or spalling the edges of the pavement to remain. The
machine shall have a positive method of controlling the depth of cut.
The Engineer shall layout the area to be milled. The area shall be laid
out with straightedges in increments of 1-foot widths. The area to be
milled shall cover only the failed area. Any excessive area that is
milled because the Contractor doesn\'t have the appropriate machine, or
areas that are damaged because of his negligence, shall not be included
in the measurement for payment.

**b. Profiling, Grade Correction, or Surface Correction:** The machine
shall have a minimum width of 10 feet. It shall be equipped with
electronic grade control devices on both sides that will cut the surface
to the grade and tolerances specified. The machine shall cut vertical
edges. A positive method of dust control shall be provided. The machine
shall be capable of discharging the millings in a truck or leaving them
in a defined windrow.

Method of Measurement

**101-4.1. MEASUREMENT.**

**a. General:** If there is no quantity shown in the bidding schedule,
the work covered by this section shall be considered as a subsidiary
obligation of the Contractor covered under the other contract items.
Only accepted work will be measured.

**b. Pavement Removal:** The unit of measurement for pavement removal
shall be the number of square yards removed by the Contractor. Any
pavement removed outside the limits of removal because the pavement was
damaged by negligence on the part of the Contractor shall not be
included in the measurement for payment.

**c. Joint and Crack Repair:** The unit of measurement for joint and
crack repair shall be the linear foot of joint.

**d. Paint and Rubber Removal:** The unit of measurement for paint and
rubber removal shall be the square foot.

**e. Spall and Failed Asphaltic Concrete Pavement Repair**:

> **(1)** The unit of measure for concrete spall repair shall be the
> number of square feet. The average depth of the patch shall be agreed
> upon by the Contractor and the Resident Engineer. The quantity shall
> be divided in the following categories:

\(a\) 0 to 4 inches in average depth.

\(b\) 4 to 8 inches in average depth.

\(c\) Greater than 8 inches in average depth.

> **(2)** The unit of measure for failed asphaltic concrete pavement
> shall be as follow:

\(a\) Asphaltic Concrete Square Yards.

\(b\) Base Course Square Yards.

\(c\) Subbase Course Square Yards.

\(d\) Subgrade Square Yards.

f\. Cold Planing: The unit of measure for cold planing shall be the
number square yards. The average depth of the cold planing shall be
determined by the Engineer and the Contractor prior to accomplish­ment of
the work. When surface correction is required, if the initial cut
doesn\'t correct the condition, the Contractor shall re-plane the area
and will be paid only once for the total depth of planning. The quantity
shall be divided into the following categories:

\(a\) 0 to 2 inches (d) 0 to 5 inches

\(b\) 0 to 3 inches (e) 0 to 6 inches

\(c\) 0 to 4 inches

BASIS OF PAYMENT

**101-5.1 Payment.** Payment shall be made at contract unit price for
the unit of measurement as specified hereinbefore. This price shall be
full compensation for furnishing all materials and for all preparation,
hauling, and placing of the material and for all labor, equipment,
tools, and incidentals necessary to complete this item.

**END OF ITEM P-101**

### **ITEM P-151 CLEARING AND GRUBBING**

DESCRIPTION

**151-1.1** This item shall consist of clearing or clearing and
grubbing, including the disposal of materials, for all areas within the
limits designated on the plans or as required by the Engineer.

Clearing shall consist of the cutting and removal of all trees, stumps,
brush, logs, hedges, the removal of fences and other loose or projecting
material from the designated areas.  The grubbing of stumps and roots
will not be required.

Clearing, when so designated, shall consist of the cutting and removal
of isolated single trees or isolated groups of trees.  The cutting of
all the trees of this classification shall be in accordance with the
requirements for the particular area being cleared, or as shown on the
plans, or as directed by the Engineer.  The trees shall be considered
isolated when they are 40 feet (12 m) or more apart, with the exception
of a small clump of approximately five trees or less.

Clearing and grubbing shall consist of clearing the surface of the
ground of the designated areas of all trees, stumps, down timber, logs,
snags, brush, undergrowth, hedges, heavy growth of grass or weeds,
fences, structures, debris, and rubbish of any nature, natural
obstructions or such material which in the opinion of the Engineer is
unsuitable for the foundation of strips, pavements, or other required
structures, including the grubbing of stumps, roots, matted roots,
foundations, and the disposal from the project of all spoil materials
resulting from clearing and grubbing by burning or otherwise.

CONSTRUCTION METHODS

**151-2.1**  **GENERAL.**  The areas denoted on the plans to be cleared
or cleared and grubbed shall be staked on the ground by the Engineer. 
The clearing and grubbing shall be done at a satisfactory distance in
advance of the grading operations.

All spoil materials removed by clearing or by clearing and grubbing
shall be disposed of by burning, when permitted by local laws, or by
removal to approved disposal areas.  When burning of material is
permitted, it shall be burned under the constant care of competent
watchmen so that the surrounding vegetation and other adjacent property
will not be jeopardized.  Burning shall be done in accordance with all
applicable laws, ordinances, and regulations.  Before starting any
burning operations, the Contractor shall notify the agency having
jurisdiction.

As far as practicable, waste concrete and masonry shall be placed on
slopes of embankments or channels.  When embankments are constructed of
such material, this material shall be placed in accordance with
requirements for formation of embankments.  Any broken concrete or
masonry that cannot be used in construction, and all other materials not
considered suitable for use elsewhere, shall be disposed of by the
Contractor.  In no case shall any discarded materials be left in
windrows or piles adjacent to or within the airport limits.  The manner
and location of disposal of materials shall be subject to the approval
of the Engineer and shall not create an unsightly or objectionable
view.  When the Contractor is required to locate a disposal area outside
the airport property limits at his/her own expense, he shall obtain and
file with the Engineer, permission in writing from the property owner
for the use of private property for this purpose.

If the plans or the specifications require the saving of merchantable
timber, the Contractor shall trim the limbs and tops from designated
trees, saw them into suitable lengths, and make the material available
for removal by other agencies.

Any blasting necessary shall be done at the Contractor\'s
responsibility, and the utmost care shall be taken not to endanger life
or property.

The removal of existing structure and utilities required to permit
orderly progress of work shall be accomplished by local agencies, unless
otherwise shown on the plans.  Whenever a telephone or telegraph pole,
pipeline, conduit, sewer, roadway, or other utility is encountered and
must be removed or relocated, the Contractor shall advise the Engineer
who will notify the proper local authority or owner and attempt to
secure prompt action.

**151-2.2 CLEARING.**  The Contractor shall clear the staked or
indicated area of all objectionable materials.  Trees unavoidably
falling outside the specified limits must be cut up, removed, and
disposed of in a satisfactory manner.  In order to minimize damage to
trees that are to be left standing, trees shall be felled toward the
center of area being cleared.  The Contractor shall preserve and protect
from injury all trees not to be removed.  The trees, stumps, and brush
shall be cut to a height of not more than 12 inches (300 mm) above the
ground.  The grubbing of stumps and roots will not be required.

When isolated trees are designated for clearing, the trees shall be
classed in accordance with the butt diameter size as measured at a point
18 inches (45 cm) above the ground level or at a designated height
specified in the proposal.

Fences shall be removed and disposed of when directed by the Engineer. 
Fence wire shall be neatly rolled and the wire and posts stored on the
airport if they are to be used again, or stored at a designated location
if the fence is to remain the property of a local owner or of a civic
authority.

**151-2.3 CLEARING AND GRUBBING.**  In areas designated to be cleared
and grubbed, all stumps, roots, buried logs, brush, grass, and other
unsatisfactory materials shall be removed, except where embankments
exceeding 3‑1/2 feet (105 cm) in depth are to be made outside of paved
areas.  In cases where such depth of embankments is to be made, all
unsatisfactory materials shall be removed, but sound trees, stumps, and
brush can be cut off within 6 inches (150 mm) above the ground and
allowed to remain.  Tap roots and other projections over 1‑1/2 inches
(37 mm) in diameter shall be grubbed out to a depth of at least 18
inches (45 cm) below the finished subgrade or slope elevation.

Any buildings and miscellaneous structures that are shown on the plans
to be removed shall be demolished or removed, and all materials there
from shall be disposed of either by burning or otherwise removed from
the site.  The remaining or existing foundations, wells, cesspools, and
all like structures shall be destroyed by breaking out or breaking down
the materials of which the foundations, wells, cesspools, etc., are
built to a depth at least 2 feet (60 cm) below the existing surrounding
ground.  Any broken concrete, blocks, or other objectionable material
that cannot be used in backfill shall be removed and disposed of.  The
holes or openings shall be backfilled with acceptable material and
properly compacted.

All holes remaining after the grubbing operation in embankment areas
shall have the sides broken down to flatten out the slopes, and shall be
filled with acceptable material, moistened and properly compacted in
layers to the density required in Item P‑152.  The same construction
procedure shall be applied to all holes remaining after grubbing in
excavation areas where the depth of holes exceeds the depth of the
proposed excavation.

METHOD OF MEASUREMENT

**151-3.1**  The quantities of clearing or clearing and grubbing as
shown by the limits on the plans or as ordered by the Engineer shall be
the number of acres (square meters) or fractions thereof, of land
specifically cleared or cleared and grubbed.

When isolated trees are designated for clearing, the quantities of
trees, as determined in accordance with ranges of butt diameter size,
measured at a point 18 inches (45 cm) above the ground level at the
tree, shall be paid for according to the schedule of sizes as follows:

The number of trees:

From 0 to 2‑1/2 feet (75 cm), butt diameter

From 2‑1/2 to 5 feet (75 to 150 cm), butt diameter

For 5 feet (150 cm) or more, butt diameter

BASIS OF PAYMENT

**151-4.1**  Payment shall be made at the contract unit price per acre
(square meter) for clearing.  This price shall be full compensation for
furnishing all materials and for all labor, equipment, tools, and
incidentals necessary to complete the item.

**151-4.2**  Payment shall be made at the contract unit price for
clearing isolated trees.  This price shall be full compensation for
furnishing all materials and for all labor, equipment, tools, and
incidentals necessary to complete the item.

**151-4.3**  Payment shall be made at the contract unit price per acre
(square meter) for clearing and grubbing.  This price shall be full
compensation for furnishing all materials and for all labor, equipment,
tools, and incidentals necessary to complete the item.

Payment will be made under:

Item P‑151‑4.1  Clearing---per acre (square meter)

Item P‑151‑4.2  Clearing for isolated trees:

From 0 to 2‑1/2 feet (75 cm) butt diameter, per tree

From 2‑1/2 to 5 feet (75 to 150 cm) butt diameter, per tree

For 5 feet (150 cm) or more butt diameter, per tree

Item P‑151‑4.3  Clearing and grubbing---per acre (square meter)

**END OF ITEM P-151**

**Intentionally Left Blank**

### **ITEM P-152 EXCAVATION AND EMBANKMENT**

DESCRIPTION

**152-1.1**  This item covers excavation, disposal, placement, and
compaction of all materials within the limits of the work required to
construct safety areas, runways, taxiways, aprons, and intermediate as
well as other areas for drainage, building construction, parking, or
other purposes in accordance with these specifications and in conformity
to the dimensions and typical section(s) shown on the plans.

**152-1.2 CLASSIFICATION.**  All material excavated shall be classified
as defined below:

**a. Unclassified Excavation.**  Unclassified excavation shall consist
of the excavation and disposal of all material, regardless of its
nature, which is not otherwise classified and paid for under the
following items.

**b. Rock Excavation.**  Rock excavation shall include all solid rock in
ledges, in bedded deposits, in unstratified masses, and conglomerate
deposits which are so firmly cemented they cannot be removed without
blasting or using rippers.  All boulders containing a volume of more
than 1/2 cubic yard (0.4 cubic meter) will be classified as \`\`rock
excavation.\'\'

**c. Muck Excavation.**  Muck excavation shall consist of the removal
and disposal of deposits or mixtures of soils and organic matter not
suitable for foundation material.  Muck shall include materials that
will decay or produce subsidence in the embankment.  It may be made up
of decaying stumps, roots, logs, humus, or other material not
satisfactory for incorporation in the embankment.

**d. Drainage Excavation.**  Drainage excavation shall consist of all
excavation made for the primary purpose of drainage and includes
drainage ditches, such as intercepting, inlet or outlet; temporary levee
construction; or any other type as shown on the plans.

**e. Borrow Excavation.**  Borrow excavation shall consist of approved
material required for the construction of embankment or for other
portions of the work in excess of the quantity of usable material
available from required excavations.  Borrow material shall be obtained
from areas within the limits of the airport property but outside the
normal limits of necessary grading, or from areas outside the airport.

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> **All material excavated shall be considered \`\`unclassified\'\'
> unless the Engineer specifies other classifications in the project
> specifications.**
>
> **Delete the classifications not applicable to a project.**

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**152-1.3 Unsuitable Excavation.**  Any material containing vegetable or
organic matter, such as muck, peat, organic silt, or sod shall be
considered unsuitable for use in embankment construction.  Material,
when approved by the Engineer as suitable to support vegetation, may be
used on the embankment slope.

CONSTRUCTION METHODS

**152-2.1 General.**  Before beginning excavation, grading, and
embankment operations in any area, the area shall be completely cleared
and grubbed in accordance with Item P‑151.

The suitability of material to be placed in embankments shall be subject
to approval by the Engineer.  All unsuitable material shall be disposed
of in waste areas shown on the plans.  All waste areas shall be graded
to allow positive drainage of the area and of adjacent areas.  The
surface elevation of waste areas shall not extend above the surface
elevation of adjacent usable areas of the airport, unless specified on
the plans or approved by the Engineer.

When the Contractor\'s excavating operations encounter artifacts of
historical or archaeological significance, the operations shall be
temporarily discontinued.  At the direction of the Engineer, the
Contractor shall excavate the site in such a manner as to preserve the
artifacts encountered and allow for their removal.  Such excavation will
be paid for as extra work.

Those areas outside of the pavement areas in which the top layer of soil
material has become compacted, by hauling or other activities of the
Contractor shall be scarified and disked to a depth of 4 inches (100
mm), in order to loosen and pulverize the soil.

If it is necessary to interrupt existing surface drainage, sewers or
under‑drainage, conduits, utilities, or similar underground structures,
the Contractor shall be responsible for and shall take all necessary
precautions to preserve them or provide temporary services.  When such
facilities are encountered, the Contractor shall notify the Engineer,
who shall arrange for their removal if necessary.  The Contractor shall,
at his/her own expense, satisfactorily repair or pay the cost of all
damage to such facilities or structures that may result from any of the
Contractor\'s operations during the period of the contract.

**152-2.2 EXCAVATION.**  No excavation shall be started until the work
has been staked out by the Contractor and the Engineer has obtained
elevations and measurements of the ground surface.  All suitable
excavated material shall be used in the formation of embankment,
subgrade, or for other purposes shown on the plans.  All unsuitable
material shall be disposed of as shown on the plans.

When the volume of the excavation exceeds that required to construct the
embankments to the grades indicated, the excess shall be used to grade
the areas of ultimate development or disposed of as directed.  When the
volume of excavation is not sufficient for constructing the fill to the
grades indicated, the deficiency shall be obtained from borrow areas.

The grade shall be maintained so that the surface is well drained at all
times.  When necessary, temporary drains and drainage ditches shall be
installed to intercept or divert surface water that may affect the work.

**a. Selective Grading.**  When selective grading is indicated on the
plans, the more suitable material as designated by the Engineer shall be
used in constructing the embankment or in capping the pavement
subgrade.  If, at the time of excavation, it is not possible to place
this material in its final location, it shall be stockpiled in approved
areas so that it can be measured for payment for rehandling as specified
in paragraph 3.3.

**b. Undercutting.**  Rock, shale, hardpan, loose rock, boulders, or
other material unsatisfactory for safety areas, subgrades, roads,
shoulders, or any areas intended for turfing shall be excavated to a
minimum depth of 12 inches (300 mm), or to the depth specified by the
Engineer, below the subgrade.  Muck, peat, matted roots, or other
yielding material, unsatisfactory for subgrade foundation, shall be
removed to the depth specified.  Unsuitable materials shall be disposed
of at locations shown on the plans.  This excavated material shall be
paid for at the contract unit price per cubic yard (per cubic meter) for
**\[ \]**.  The excavated area shall be refilled with suitable material
obtained from the grading operations or borrow areas and compacted to
specified densities.  The necessary refilling will constitute a part of
the embankment.  Where rock cuts are made and refilled with selected
material, any pockets created in the rock surface shall be drained in
accordance with the details shown on the plans.

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> **The Engineer shall specify the appropriate class of excavation. If
> rock or muck excavation is not included under paragraph 1.2,
> unclassified excavation should be specified.**
>
> **The plans shall show details for draining pockets created in rock
> cuts.**

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**c. Overbreak.**  Overbreak, including slides, is that portion of any
material displaced or loosened beyond the finished work as planned or
authorized by the Engineer.  The Engineer shall determine if the
displacement of such material was unavoidable and his/her decision shall
be final.  All overbreak shall be graded or removed by the Contractor
and disposed of as directed; however, payment will not be made for the
removal and disposal of overbreak that the Engineer determines as
avoidable.  Unavoidable overbreak will be classified as \`\`Unclassified
Excavation.\'\'

**d. Removal of Utilities.**  The removal of existing structures and
utilities required to permit the orderly progress of work will be
accomplished by someone other than the Contractor, e.g., the utility
unless otherwise shown on the plans.  All existing foundations shall be
excavated for at least 2 feet (60 cm) below the top of subgrade or as
indicated on the plans, and the material disposed of as directed.  All
foundations thus excavated shall be backfilled with suitable material
and compacted as specified herein.

**e. Compaction Requirements.**  The subgrade under areas to be paved
shall be compacted to a depth of **\[ \]** and to a density of not less
than **\[ \]** percent of the maximum density as determined by ASTM **\[
\].** The material to be compacted shall be within +/- 2 percent of
optimum moisture content before rolled to obtain the prescribed
compaction (except for expansive soils).

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> **Subgrades Under Flexible Pavements. The Engineer shall specify
> compaction to a depth of 6 inches (150 mm) and to a density of not
> less than 95 percent for cohesive soils or 100 percent for noncohesive
> soils for areas serving single gear aircraft.  For areas serving dual
> gear or dual tandem gear aircraft the Engineer shall specify the
> required compaction depths and densities as determined from AC
> 150/5320‑6C, Chapter 3, Section 2.**
>
> **Subgrades Under Rigid Pavements.  The Engineer shall specify the
> compaction depth and densities as determined from AC 150/5320‑6C,
> Chapter 3, Section 3.**
>
> **The Engineer shall specify ASTM D 698 for areas designated for
> aircraft with gross weights of 60,000 pounds (27 200 Kg) or less, and
> ASTM D 1557 for areas designated for aircraft with gross weights
> greater than 60,000 pounds (27 200 Kg).**
>
> **If nuclear density machines are to be used for density
> determination, the machines shall be calibrated in accordance with
> ASTM D 2922. The nuclear equipment shall be calibrated using blocks of
> materials with densities that extend through a range representative of
> the density of the proposed embankment material. (See attached Section
> 120 of the General Provisions for additional guidance with nuclear
> density testing)**
>
> **Include testing frequencies per square yard for density & moisture
> acceptance tests.**
>
> **AASHTO T99 or T-180 (Moisture-Density) should be specified for soils
> that are expected to have more than 30% retained on the 3/4-inch
> sieve. The moisture-density relationship test procedures ASTM D 698
> and D1557 are not applicable for materials with greater than 30
> retained on the 3/4-inch sieve. A replacement procedure (ASTM D 4718)
> for the coarse material (greater than 3/4-inch) is used with ASTM
> methods but only until up to 30 percent is retained. Maximum density
> testing (ASTM D 4253) may be used but it also limits the material
> retained on the 1-1/2-inch sieve to 30 percent. The AASHTO T-99 and
> T-180 are similar to ASTM D 698 and D 1557, except they do not limit
> the replacement of the coarse material.**

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The in‑place field density shall be determined in accordance with ASTM D
1556 or ASTM D 2167.  Stones or rock fragments larger than 4 inches (100
mm) in their greatest dimension will not be permitted in the top 6
inches (150 mm) of the subgrade.  The finished grading operations,
conforming to the typical cross section, shall be completed and
maintained at least 1,000 feet (300 m) ahead of the paving operations or
as directed by the Engineer.

In cuts, all loose or protruding rocks on the back slopes shall be
barred loose or otherwise removed to line of finished grade of slope. 
All cut‑and‑fill slopes shall be uniformly dressed to the slope, cross
section, and alignment shown on the plans or as directed by the
Engineer.

Blasting will be permitted only when proper precautions are taken for
the safety of all persons, the work, and the property.  All damage done
to the work or property shall be repaired at the Contractor\'s expense. 
All operations of the Contractor in connection with the transportation,
storage, and use of explosives shall conform to all state and local
regulations and explosive manufacturers\' instructions, with applicable
approved permits reviewed by the Engineer.  Any approval given, however,
will not relieve the Contractor of his/her responsibility in blasting
operations.

Where blasting is approved, the Contractor shall employ a vibration
consultant, approved by the Engineer, to advise on explosive charge
weights per delay and to analyze records from seismograph recordings.
The seismograph shall be capable of producing a permanent record of the
three components of the motion in terms of particle velocity, and in
addition shall be capable of internal dynamic calibration.

In each distinct blasting area, where pertinent factors affecting blast
vibrations and their effects in the area remain the same, the Contractor
shall submit a blasting plan of the initial blasts to the Engineer for
approval.  This plan must consist of hole size, depth, spacing, burden,
type of explosives, type of delay sequence, maximum amount of explosive
on any one delay period, depth of rock, and depth of overburden if any. 
The maximum explosive charge weights per delay included in the plan
shall not be increased without the approval of the engineering.

The Contractor shall keep a record of each blast fired---its date, time
and location; the amount of explosives used, maximum explosive charge
weight per delay period, and, where necessary, seismograph records
identified by instrument number and location.

These records shall be made available to the Engineer on a monthly basis
or in tabulated form at other times as required.

**152-2.3 BORROW EXCAVATION.** Borrow area(s) within the airport
property are indicated on the plans.  Borrow excavation shall be made
only at these designated locations and within the horizontal and
vertical limits as staked or as directed.

When borrow sources are outside the boundaries of the airport property,
it shall be the Contractor\'s responsibility to locate and obtain the
supply, subject to the approval of the Engineer.  The Contractor shall
notify the Engineer, at least 15 days prior to beginning the excavation,
so necessary measurements and tests can be made.  All unsuitable
material shall be disposed of by the Contractor.  All borrow pits shall
be opened up to expose the vertical face of various strata of acceptable
material to enable obtaining a uniform product.  Borrow pits shall be
excavated to regular lines to permit accurate measurements, and they
shall be drained and left in a neat, presentable condition with all
slopes dressed uniformly.

**152-2.4 DRAINAGE EXCAVATION.**  Drainage excavation shall consist of
excavating for drainage ditches such as intercepting; inlet or outlet,
for temporary levee construction; or for any other type as designed or
as shown on the plans.  The work shall be performed in the proper
sequence with the other construction.  All satisfactory material shall
be placed in fills; unsuitable material shall be placed in waste areas
or as directed.  Intercepting ditches shall be constructed prior to
starting adjacent excavation operations.  All necessary work shall be
performed to secure a finish true to line, elevation, and cross section.

The Contractor shall maintain ditches constructed on the project to the
required cross section and shall keep them free of debris or
obstructions until the project is accepted.

**152-2.5 PREPARATION OF EMBANKMENT AREA.**  Where an embankment is to
be constructed to a height of 4 feet (120 cm) or less, all sod and
vegetable matter shall be removed from the surface upon which the
embankment is to be placed, and the cleared surface shall be completely
broken up by plowing or scarifying to a minimum depth of 6 inches (150
mm).  This area shall then be compacted as indicated in paragraph 2.6. 
When the height of fill is greater than 4 feet (120 cm), sod not
required to be removed shall be thoroughly disked and recompacted to the
density of the surrounding ground before construction of embankment.

Where embankments are to be placed on natural slopes steeper than 3 to
1, horizontal benches shall be constructed as shown on the plans.

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> **The Engineer shall include benching details on the plans based on
> the type of material, degree of consolidation of the material, and the
> degree of homogeneity of the material.  The minimum width of the bench
> shall be sufficient to accommodate construction equipment.**

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No direct payment shall be made for the work performed under this
section.  The necessary clearing and grubbing and the quantity of
excavation removed will be paid for under the respective items of work.

**152-2.6 FORMATION OF EMBANKMENTS.**  Embankments shall be formed in
successive horizontal layers of not more than 8 inches (200 mm) in loose
depth for the full width of the cross section, unless otherwise approved
by the Engineer.

The grading operations shall be conducted, and the various soil strata
shall be placed, to produce a soil structure as shown on the typical
cross section or as directed.  Materials such as brush, hedge, roots,
stumps, grass and other organic matter, shall not be incorporated or
buried in the embankment.

Operations on earthwork shall be suspended at any time when satisfactory
results cannot be obtained because of rain, freezing, or other
unsatisfactory conditions of the field.  The Contractor shall drag,
blade, or slope the embankment to provide proper surface drainage.

The material in the layer shall be within +/-2 percent of optimum
moisture content before rolling to obtain the prescribed compaction.  In
order to achieve a uniform moisture content throughout the layer,
wetting or drying of the material and manipulation shall be required
when necessary.  Should the material be too wet to permit proper
compaction or rolling, all work on all of the affected portions of the
embankment shall be delayed until the material has dried to the required
moisture content.  Sprinkling of dry material to obtain the proper
moisture content shall be done with approved equipment that will
sufficiently distribute the water.  Sufficient equipment to furnish the
required water shall be available at all times.  Samples of all
embankment materials for testing, both before and after placement and
compaction, will be taken for each **\[ \]**.  Based on these tests, the
Contractor shall make the necessary corrections and adjustments in
methods, materials or moisture content in order to achieve the correct
embankment density.

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> **It is recommended that density tests be made for each 1000 cubic
> yards (760 cubic meters) of material placed per layer.  The Engineer
> may specify other frequencies as appropriate to the job size.  If it
> is necessary (because of the presence of expansive soils or other
> unusually sensitive soils) to apply special controls to the moisture
> content of the soil during or after compaction to ensure strength, the
> Engineer shall specify the appropriate moisture content.  The moisture
> limitations shall be specified using acceptable moisture ranges as
> determined by ASTM D 698 or ASTM D 1557.**
>
> **If nuclear density machines are to be used for density
> determination, the machines shall be calibrated in accordance with
> ASTM D 2922. The nuclear equipment shall be calibrated using blocks of
> materials with densities that extend through a range representative of
> the density of the proposed embankment material. (See attached Section
> 120 of the General Provisions for additional guidance with nuclear
> density testing)**
>
> **Include testing frequencies per square yard for density & moisture
> acceptance tests.**
>
> **AASHTO T99 or T-180 (Moisture-Density) should be specified for soils
> that are expected to have more than 30% retained on the 3/4-inch
> sieve. The moisture-density relationship test procedures ASTM D 698
> and D1557 are not applicable for materials with greater than 30
> retained on the 3/4-inch sieve. A replacement procedure (ASTM D 4718)
> for the coarse material (greater than 3/4-inch) is used with ASTM
> methods but only until up to 30 percent is retained. Maximum density
> testing (ASTM D 4253) may be used but it also limits the material
> retained on the 1-1/2-inch sieve to 30 percent. The AASHTO T-99 and
> T-180 are similar to ASTM D 698 and D 1557, except they do not limit
> the replacement of the coarse material.**

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Rolling operations shall be continued until the embankment is compacted
to not less than 95 percent of maximum density for noncohesive soils,
and 90 percent of maximum density for cohesive soils as determined by
ASTM **\[ \]**.  Under all areas to be paved, the embankments shall be
compacted to a depth of **\[ \]** and to a density of not less than **\[
\]** percent of the maximum density as determined by ASTM **\[ \]**.

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> **Subgrade Under Flexible Pavements.  The Engineer shall specify the
> required compaction depths and densities as determined from AC
> 150/5320‑6C, Chapter 3, Section 2.**
>
> **Subgrade Under Rigid Pavements.  The Engineer shall specify the
> required compaction depths and densities as determined from AC
> 150/5320‑6, Chapter 3, Section 3.**
>
> **The Engineer shall specify ASTM D 698 for areas designated for
> aircraft with gross weights of 60,000 pounds (27 200 kg) or less and
> ASTM D 1557 for areas designated for aircraft with gross weights
> greater than 60,000 pounds (27 200 kg).**
>
> **For soils with expansive characteristics, the maximum density should
> be determined in accordance with ASTM D 698 regardless of aircraft
> weight.**

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On all areas outside of the pavement areas, no compaction will be
required on the top 4 inches (100 mm).

The in‑place field density shall be determined in accordance with ASTM D
1556 or ASTM D 2167.

Compaction areas shall be kept separate, and no layer shall be covered
by another until the proper density is obtained.

During construction of the embankment, the Contractor shall route
his/her equipment at all times, both when loaded and when empty, over
the layers as they are placed and shall distribute the travel evenly
over the entire width of the embankment.  The equipment shall be
operated in such a manner that hardpan, cemented gravel, clay, or other
chunky soil material will be broken up into small particles and become
incorporated with the other material in the layer.

In the construction of embankments, layer placement shall begin in the
deepest portion of the fill; as placement progresses, layers shall be
constructed approximately parallel to the finished pavement grade line.

When rock and other embankment material are excavated at approximately
the same time, the rock shall be incorporated into the outer portion of
the embankment and the other material shall be incorporated under the
future paved areas.  Stones or fragmentary rock larger than 4 inches
(100 mm) in their greatest dimensions will not be allowed in the top 6
inches (150 mm) of the subgrade.  Rockfill shall be brought up in layers
as specified or as directed and every effort shall be exerted to fill
the voids with the finer material forming a dense, compact mass.  Rock
or boulders shall not be disposed of outside the excavation or
embankment areas, except at places and in the manner designated by the
Engineer.

When the excavated material consists predominantly of rock fragments of
such size that the material cannot be placed in layers of the prescribed
thickness without crushing, pulverizing or further breaking down the
pieces, such material may be placed in the embankment as directed in
layers not exceeding 2 feet (60 cm) in thickness.  Each layer shall be
leveled and smoothed with suitable leveling equipment and by
distribution of spalls and finer fragments of rock.  These type lifts
shall not be constructed above an elevation 4 feet (120 cm) below the
finished subgrade. 

Frozen material shall not be placed in the embankment nor shall
embankment be placed upon frozen material.

There will be no separate measurement of payment for compacted
embankment, and all costs incidental to placing in layers, compacting,
disking, watering, mixing, sloping, and other necessary operations for
construction of embankments will be included in the contract price for
excavation, borrow, or other items.

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> **The Engineer may specify payment for compacted \`\`Embankment in
> Place.\'\'  In this case, delete the preceding paragraph and indicate
> that payment will be made under embankment and that no payment will be
> made for excavation, borrow, or other items.**

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**152-2.7 FINISHING AND PROTECTION OF SUBGRADE.**  After the subgrade
has been substantially completed the full width shall be conditioned by
removing any soft or other unstable material that will not compact
properly.  The resulting areas and all other low areas, holes or
depressions shall be brought to grade with suitable select material. 
Scarifying, blading, rolling and other methods shall be performed to
provide a thoroughly compacted subgrade shaped to the lines and grades
shown on the plans.

Grading of the subgrade shall be performed so that it will drain
readily.  The Contractor shall take all precautions necessary to protect
the subgrade from damage.  He/she shall limit hauling over the finished
subgrade to that which is essential for construction purposes.

All ruts or rough places that develop in a completed subgrade shall be
smoothed and recompacted.

No subbase, base, or surface course shall be placed on the subgrade
until the subgrade has been approved by the Engineer.

**152-2.8 HAUL.**  All hauling will be considered a necessary and
incidental part of the work.  Its cost shall be considered by the
Contractor and included in the contract unit price for the pay of items
of work involved.  No payment will be made separately or directly for
hauling on any part of the work.

**152-2.9 TOLERANCES.**  In those areas upon which a subbase or base
course is to be placed, the top of the subgrade shall be of such
smoothness that, when tested with a 16‑foot (4.8 m) straightedge applied
parallel and at right angles to the centerline, it shall not show any
deviation in excess of 1/2‑inch (12 mm), or shall not be more than
0.05‑foot (.015 m) from true grade as established by grade hubs or
pins.  Any deviation in excess of these amounts shall be corrected by
loosening, adding, or removing materials; reshaping; and recompacting by
sprinkling and rolling.

On safety areas, intermediate and other designated areas, the surface
shall be of such smoothness that it will not vary more than 0.10 foot
(0.03 m) from true grade as established by grade hubs.  Any deviation in
excess of this amount shall be corrected by loosening, adding or
removing materials, and reshaping.

**152-2.10 TOPSOIL.**  When topsoil is specified or required as shown on
the plans or under Item T‑905, it shall be salvaged from stripping or
other grading operations.  The topsoil shall meet the requirements of
Item T‑905.  If, at the time of excavation or stripping, the topsoil
cannot be placed in its proper and final section of finished
construction, the material shall be stockpiled at approved locations. 
Stockpiles shall not be placed within **\[ \]** feet of runway pavement
or **\[ \]** feet of taxiway pavement and shall not be placed on areas
that subsequently will require any excavation or embankment.  If, in the
judgment of the Engineer, it is practical to place the salvaged topsoil
at the time of excavation or stripping, the material shall be placed in
its final position without stockpiling or further rehandling.

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> **The Engineer shall specify the appropriate clearances in accordance
> with AC 150/5370‑2C, Operational Safety on Airports During
> Construction, Appendix 1.**

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Upon completion of grading operations, stockpiled topsoil shall be
handled and placed as directed, or as required in Item T‑905.

No direct payment will be made for topsoil as such under Item P‑152. 
The quantity removed and placed directly or stockpiled shall be paid for
at the contract unit price per cubic yard (cubic meter) for
\`\`Unclassified Excavation.\'\'

When stockpiling of topsoil and later rehandling of such material is
directed by the Engineer, the material so rehandled shall be paid for at
the contract unit price per cubic yard (cubic meter) for
\`\`Topsoiling,\'\' as provided in Item T‑905.

METHOD OF MEASUREMENT

**152-3.1**  The quantity of excavation to be paid for shall be the
number of cubic yards (cubic meters) measured in its original position.

Measurement shall not include the quantity of materials excavated
without authorization beyond normal slope lines, or the quantity of
material used for purposes other than those directed.

**152-3.2**  Borrow material shall be paid for on the basis of the
number of cubic yards (cubic meters) measured in its original position
at the borrow pit.

**152-3.3**  Stockpiled material shall be paid for on the basis of the
number of cubic yards (cubic meters) measured in the stockpiled position
as soon as the material has been stockpiled.

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> **If the Engineer wishes to specify payment for the quantity of
> embankment in place in lieu of paying for excavation, delete paragraph
> 3.1 and substitute the following:  The quantity of embankment to be
> paid for shall be the number of cubic yards (cubic meters) measured in
> its final position.**

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**152-3.4**  For payment specified by the cubic yard (cubic meter),
measurement for all **\[excavation\] \[embankment\]** shall be computed
by the average end area method.  The end area is that bound by the
original ground line established by field cross sections and the final
theoretical pay line established by **\[excavation\] \[embankment\]**
cross sections shown on the plans, subject to verification by the
Engineer.  After completion of all **\[excavation\] \[embankment\]**
operations and prior to the placing of base or subbase material, the
final **\[excavation\] \[embankment\]** shall be verified by the
Engineer by means of field cross sections taken randomly at intervals
not exceeding 500 linear feet (150 meters).

Final field cross sections shall be employed if the following changes
have been made:

**a.**  Plan width of embankments or excavations are changed by more
than plus or minus 1.0 foot (0.3 meter); or

**b.**  Plan elevations of embankments or excavations are changed by
more than plus or minus 0.5 foot (0.15 meter).

BASIS OF PAYMENT

**152-4.1**  For \`\`Unclassified excavation\'\' payment shall be made
at the contract unit price per cubic yard (cubic meter).  This price
shall be full compensation for furnishing all materials, labor,
equipment, tools, and incidentals necessary to complete the item.

**152-4.2**  For \`\`Rock Excavation\'\' payment shall be made at the
contract unit price per cubic yard (cubic meter).  This price shall be
full compensation for furnishing all materials, labor, equipment, tools,
and incidentals necessary to complete the item.

**152-4.3**  For \`\`Muck Excavation\'\' payment shall be made at the
contract unit price per cubic yard (cubic meter).  This price shall be
full compensation for furnishing all materials, labor, equipment, tools,
and incidentals necessary to complete the item.

**152-4.4**  For \`\`Drainage Excavation\'\' payment shall be made at
the contract unit price per cubic yard (cubic meter).  This price shall
be full compensation for furnishing all materials, labor, equipment,
tools, and incidentals necessary to complete the item.

**152-4.5**  For \`\`Borrow Excavation\'\' payment shall be made at the
contract unit price per cubic yard (cubic meter).  This price shall be
full compensation for furnishing all materials, labor, equipment, tools,
and incidentals necessary to complete the item.

**152-4.6**  For \`\`Stockpiled Material\'\' payment shall be made at
the contract unit price per cubic yard (cubic meter).  This price shall
be full compensation for furnishing all materials, labor, equipment,
tools, and incidentals necessary to complete the item.

**152-4.7**  For \`\`Embankment in Place\'\' payment shall be made at
the contract unit price per cubic yard (cubic meter).  This price shall
be full compensation for furnishing all materials, labor, equipment,
tools, and incidentals necessary to complete the item.

Payment will be made under:

Item P‑152‑4.1 Unclassified Excavation---per cubic yard (cubic meter)

Item P‑152‑4.2 Rock Excavation---per cubic yard (cubic meter)

Item P‑152‑4.3 Muck Excavation---per cubic yard (cubic meter)

Item P‑152‑4.4 Drainage Excavation---per cubic yard (cubic meter)

Item P‑152‑4.5 Borrow Excavation---per cubic yard (cubic meter)

Item P‑152‑4.6 Stockpiled material---per cubic yard (cubic meter)

Item P‑152‑4.7 Embankment in Place---per cubic yard (cubic meter)

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> **The Engineer shall include only those classifications shown in the
> bid schedule.**

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TESTING REQUIREMENTS

ASTM D 698 Test for Moisture‑Density Relations of Soils and
Soil‑Aggregate Mixtures, Using 5.5‑pound (2.49 kg) Rammer and 12‑inch
(305 mm) Drop

ASTM D 1556 Test for Density of Soil In Place by the Sand-Cone Method

ASTM D 1557 Test for Laboratory Compaction Characteristics of Soil Using
Modified Effort

ASTM D 2167 Test for Density and Unit Weight of Soil In Place by the
Rubber Ballon Method.

**END OF ITEM P-152**

### **ITEM P-153 CONTROLLED LOW-STRENGTH MATERIAL (CLSM)**

DESCRIPTION

**153.1.1** This item shall consist of furnishing, transporting, and
placing a controlled low-strength material (CLSM) as flowable backfill
in trenches or at other locations shown on the plans or as directed by
the Engineer.

MATERIALS

**153-2.1 MATERIALS**

**a. Portland Cement.** Portland cement shall conform to the
requirements of ASTM **\[ \]** Type **\[ \]**. If for any reason, cement
becomes partially set or contains lumps of caked cement, it shall be
rejected. Cement salvaged from discarded or used bags shall not be used.

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> **The Engineer shall specify one of the following : ASTM C 150 - Type
> I, II.**
>
> **ASTM C 595 - Type IP, IS, S, I(PM).**

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**b. Fly Ash.** Fly Ash shall conform to ASTM C 618, Class C or F.

**c. Fine Aggregate (Sand).** Fine aggregate shall conform to the
requirements of ASTM C 33 except for aggregate gradation. Any aggregate
gradation which produces performance characteristics of the CLSM
specified herein will be accepted, except as follows.

**[Sieve Size Percent Passing by weight]{.underline}**

3/4 inch (19.0 mm) 100

No. 200 (0.075 mm) 0 - 12

**d. Water.** Water used in mixing shall be free of oil, salt, acid,
alkali, sugar, vegetable matter, or other substances injurious to the
finished product.

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> **Dyes and other methods of coloring the backfill material may be
> incorporated if desired.**

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MIX DESIGN

**153-3.1 PROPORTIONS.** The contractor shall submit, to the Engineer, a
mix design including the proportions and source of materials,
admixtures, and dry cubic yard (cubic meter) batch weights. The mix
shall contain a minimum of 50 pounds of cement and 250 pounds fly ash
per cubic yard (30 kg of cement and 148 kg of fly ash per cubic meter),
with the remainder of the volume composed of sand, water, and any
approved admixtures.

**a. Compressive Strength.** CLSM shall be designed to achieve a 28-day
compressive strength of 100 to 200 psi (690 to 3 680 kPa)when tested in
accordance with ASTM C 39. There should be no significant strength gain
after 28 days. Test specimens shall be made in accordance with ASTM C 31
except that the samples will not be rodded or vibrated and shall be air
cured in their molds for the duration of the cure period.

**b. Consistency.** Consistency of the fresh mixture shall be such that
the mixture may be placed without segregation. A desired consistency may
be approximated by filling an open-ended three-inch (75 mm) diameter
cylinder, six inches (150 mm) high to the top, with the mixture and the
cylinder immediately pulled straight up. The correct consistency of the
mixture will produce an approximate eight-inch (205 mm) diameter
circular-type spread without segregation. Adjustments of the proportions
of materials should be made to achieve proper solid suspension and
flowable characteristics, however the theoretical yield shall be
maintained at one cubic yard (cubic meter) for the given batch weights.

CONSTRUCTION METHODS

**153-4.1 PLACEMENT**.

**a. Placement**. CLSM may be placed by any reasonable means from a
mixing unit into the space to be filled. Agitation is required during
transportation and waiting time. Placement shall be performed in such a
manner that structures or pipes are not displaced from their desired
final position and intrusion of CLSM into undesirable areas is avoided.
The material shall be brought up uniformly to the fill line shown on the
plans or as directed to the Engineer. Each placement of CLSM shall be as
continuous an operation as possible. If CLSM is placed in more than one
layer, the base layer shall be free of surface water and loose of
foreign material prior to placement of the next layer.

**b. Limitations of Placement.** CLSM shall not be placed on frozen
ground. Mixing and placing may begin when the air or ground temperature
is at least 35 degrees F (2 degrees C) and rising. At the time of
placement, CLSM shall have a temperature of at least 40 degrees F (4
degrees C). Mixing and placement shall stop when the air temperature is
40 degrees F (4 degrees C) and falling or when the anticipated air or
ground temperature will be 35 degrees F (2 degrees C) or less in the 24
hour period following proposed placement.

**153-4.2 CURING AND PROTECTION**

**a. Curing.** The air in contact with the CLSM should be maintained at
temperatures above freezing for a minimum of 72 hours. If the CLSM is
subjected to temperatures below 32 degrees F (0 degrees C), the material
may be rejected by the Engineer if damage to the material is observed.

**b. Protection.** The CLSM shall not be subject to loads and shall
remain undisturbed by construction activities for a period of 48 hours
or until a compressive strength of 15 psi (105 kPa) is obtained. The
Contractor shall be responsible for providing evidence to the Engineer
that the material has reached the desired strength. Acceptable evidence
shall be based upon compressive tests made in accordance with paragraph
153-3.1a.

MATERIAL ACCEPTANCE

**153-5.1 Acceptance.** Acceptance of CLSM delivered and placed as shown
on the plans or as directed by the Engineer shall be based upon mix
design approval and batch tickets provided by the Contractor to confirm
that the delivered material conforms to the mix design. The Contractor
shall verify by additional testing, each 5,000 cubic yards (3,825 cubic
meters) of material used. Verification shall include confirmation of
material proportions and tests of compressive strength to confirm that
the material meets the original mix design and the requirements of CLSM
as defined in this specification. Adjustments shall be made as necessary
to the proportions and materials prior to further production.

METHOD OF MEASUREMENT

**153-6.1 Measurement.** Controlled low strength material shall be
measured by the number of **\[cubic yards (cubic meters)\]** as computed
from the neatline plan and section, adjusted for the quantities for any
embedments, and as specified, completed, and accepted..

BASIS OF PAYMENT

**153-7.1 Payment.** Accepted quantities of controlled low strength
material shall be paid for at the contract unit price per **\[cubic yard
(cubic meter)\]**. Payment shall be full compensation for all materials,
equipment, labor, and incidentals required to complete the work as
specified.

TESTING REQUIREMENTS

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

ASTM C 39 Compressive Strength of Cylindrical Concrete

MATERIAL REQUIREMENTS

ASTM C 33 Specification for Concrete Aggregates

ASTM C 150 Specification for Portland Cement

ASTM C 618 Specification for Coal Fly Ash and Raw or Calcined Natural
Pozzolan for Use as a Mineral Admixture in Concrete

ASTM C 595 Specification for Blended Hydraulic Cements

**END OF ITEM P-153**

**Intentionally Left Blank**

### **ITEM P-154 SUBBASE COURSE**

DESCRIPTION

**154-1.1**  This item shall consist of a subbase course composed of
granular materials constructed on a prepared subgrade or underlying
course in accordance with these specifications, and in conformity with
the dimensions and typical cross section shown on the plans.

MATERIALS

**154-2.1 MATERIALS.**  The subbase material shall consist of hard
durable particles or fragments of granular aggregates.  This material
will be mixed or blended with fine sand, clay, stone dust, or other
similar binding or filler materials produced from approved sources. 
This mixture must be uniform and shall comply with the requirements of
these specifications as to gradation, soil constants, and shall be
capable of being compacted into a dense and stable subbase.  The
material shall be free from vegetable matter, lumps or excessive amounts
of clay, and other objectionable or foreign substances.  Pit‑run
material may be used, provided the material meets the requirements
specified.

**TABLE 1. GRADATION REQUIREMENTS**

+-------------------------------+--------------------------------------+
| **Sieve designation (square   | **Percentage by weight passing       |
| openings)**                   | sieves**                             |
+-------------------------------+--------------------------------------+
| **as per ASTM C 136 and ASTM  |                                      |
| D 422**                       |                                      |
+-------------------------------+--------------------------------------+
|                               |                                      |
+-------------------------------+--------------------------------------+
| > 3 inch (75.0 mm)            | 100                                  |
+-------------------------------+--------------------------------------+
| > No. 10 (2.0 mm)             | 20‑100                               |
+-------------------------------+--------------------------------------+
| > No. 40 (0.450 mm)           | 5‑60                                 |
+-------------------------------+--------------------------------------+
| > No. 200 (0.075 mm)          | 0‑8                                  |
+-------------------------------+--------------------------------------+

The portion of the material passing the No. 40 (0.450 mm) 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.

The maximum amount of material finer than 0.02 mm in diameter shall be
less than 3%.

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

> **Include testing frequencies for the particle size distribution for
> preliminary and minimum of one per day during construction.**

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

CONSTRUCTION METHODS

**154-3.1 GENERAL.**  The subbase course shall be placed where
designated on the plans or as directed by the Engineer.  The material
shall be shaped and thoroughly compacted within the tolerances
specified.

Granular subbases which, due to grain sizes or shapes, are not
sufficiently stable to support without movement the construction
equipment, shall be mechanically stabilized to the depth necessary to
provide such stability as directed by the Engineer.  The mechanical
stabilization shall principally include the addition of a fine‑grained
medium to bind the particles of the subbase material sufficiently to
furnish a bearing strength, so that the course will not deform under the
traffic of the construction equipment.  The addition of the binding
medium to the subbase material shall not increase the soil constants of
that material above the limits specified.

**154-3.2 OPERATION IN PITS.**  All work involved in clearing and
stripping pits and handling unsuitable material encountered shall be
performed by the Contractor at his/her own expense.  The subbase
material shall be obtained from pits or sources that have been
approved.  The material in the pits shall be excavated and handled in
such manner that a uniform and satisfactory product can be secured.

**154-3.3 PREPARING UNDERLYING COURSE.**  Before any subbase material is
placed, the underlying course shall be prepared and conditioned as
specified.  The course shall be checked and accepted by the Engineer
before placing and spreading operations are started.

To protect the subgrade and to ensure proper drainage, the spreading of
the subbase shall begin along the centerline of the pavement on a
crowned section or on the high side of pavements with a one‑way slope.

**154-3.4 MATERIALS ACCEPTANCE IN EXISTING CONDITION.**  When the entire
subbase material is secured in a uniform and satisfactory condition and
contains approximately the required moisture, such approved material may
be moved directly to the spreading equipment for placing.  The material
may be obtained from gravel pits, stockpiles, or may be produced from a
crushing and screening plant with the proper blending.  The materials
from these sources shall meet the requirements for gradation, quality,
and consistency.  It is the intent of this section of the specifications
to secure materials that will not require further mixing.  The moisture
content of the material shall be approximately that required to obtain
maximum density.  Any minor deficiency or excess of moisture may be
corrected by surface sprinkling or by aeration.  In such instances, some
mixing or manipulation may be required, immediately preceding the
rolling, to obtain the required moisture content.  The final operation
shall be blading or dragging, if necessary, to obtain a smooth uniform
surface true to line and grade.

**154-3.5 PLANT MIXING.**  When materials from several sources are to be
blended and mixed, the subbase material shall be processed in a central
or travel mixing plant.  The subbase material, together with any blended
material, shall be thoroughly mixed with the required amount of water. 
After the mixing is complete, the material shall be transported to and
spread on the underlying course without undue loss of the moisture
content.

**154-3.5.1 MIXED IN PLACE.**  When materials from different sources are
to be proportioned and mixed or blended in place, the relative
proportions of the components of the mixture shall be as designated by
the Engineer.

The subbase material shall be deposited and spread evenly to a uniform
thickness and width.  Then the binder, filler or other material shall be
deposited and spread evenly over the first layer.  There shall be as
many layers of materials added as the Engineer may direct to obtain the
required subbase mixture.

When the required amount of materials have been placed, they shall be
thoroughly mixed and blended by means of graders, discs, harrows, rotary
tillers, supplemented by other suitable equipment if necessary.  The
mixing shall continue until the mixture is uniform throughout.  Areas of
segregated material shall be corrected by the addition of binder or
filler material and by thorough remixing.  Water in the amount and as
directed by the Engineer shall be uniformly applied prior to and during
the mixing operations, if necessary, to maintain the material at its
required moisture content.  When the mixing and blending has been
completed, the material shall be spread in a uniform layer which, when
compacted, will meet the requirements of thickness and typical cross
section.

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

> **If mixing in place will not provide a consistent subbase material,
> delete paragraph 154-3.5.1.**

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

**154-3.6 GENERAL METHODS FOR PLACING.**  The subbase course shall be
constructed in layers.  Any layer shall be not less than 3 inches (75
mm) nor more than 8 inches (200 mm) of compacted thickness.  The subbase
material shall be deposited and spread evenly to a uniform thickness and
width. The material, as spread, shall be of uniform gradation with no
pockets of fine or coarse materials.  The subbase, unless otherwise
permitted by the Engineer, shall not be spread more than 2,000 square
yards (1700 square meters) in advance of the rolling.  Any necessary
sprinkling shall be kept within this limit.  No material shall be placed
in snow or on a soft, muddy, or frozen course.

When more than one layer is required, the construction procedure
described herein shall apply similarly to each layer.

During the placing and spreading, sufficient caution shall be exercised
to prevent the incorporation of subgrade, shoulder, or foreign material
in the subbase course mixture.

**154-3.7 FINISHING AND COMPACTING.**  After spreading or mixing, the
subbase material shall be thoroughly compacted by rolling and
sprinkling, when necessary.  Sufficient rollers shall be furnished to
adequately handle the rate of placing and spreading of the subbase
course.

The field density of the compacted material shall be at least 100
percent of the maximum density of laboratory specimens prepared from
samples of the subbase material delivered to the jobsite.  The
laboratory specimens shall be compacted and tested in accordance with
**\[ \]**.  The in‑place field density shall be determined in accordance
with ASTM D 1556 or ASTM D 2922.  The moisture content of the material
at the start of compaction shall not be below nor more than 2 percentage
points above the optimum moisture content.

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

> **The Engineer shall specify ASTM D 698 for areas designated for
> aircraft with gross weights of 60,000 pounds (27 200 kg) or less and
> ASTM D 1557 for areas designated for aircraft with gross weights
> greater than 60,000 pounds (27 200 kg).**
>
> **Include testing frequencies per square yard or cubic yard for
> density and moisture acceptance tests.**
>
> **AASHTO T99 or T-180 (Moisture-Density) should be specified for soils
> that are expected to have more than 30% retained on the 3/4-inch
> sieve. The moisture-density relationship test procedures ASTM D 698
> and D1557 are not applicable for materials with greater than 30
> retained on the 3/4-inch sieve. A replacement procedure (ASTM D 4718)
> for the coarse material (greater than 3/4-inch) is used with ASTM
> methods but only until up to 30 percent is retained. Maximum density
> testing (ASTM D 4253) may be used but it also limits the material
> retained on the 1-1/2-inch sieve to 30 percent. The AASHTO T-99 and
> T-180 are similar to ASTM D 698 and D 1557, except they do not limit
> the replacement of the coarse material.**
>
> **Material meeting the requirements of Item P-154 may be free-draining
> which may prevent the material from retaining sufficient moisture to
> meet the moisture at compaction requirements of this paragraph. If
> this situation occurs during field operations, minimum moisture
> content should be established for placement of the material.**

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

When nuclear density gages are to be used for density determination,
testing shall be in accordance with Section 120.

The course shall not be rolled when the underlying course is soft or
yielding or when the rolling causes undulation in the subbase.  When the
rolling develops irregularities that exceed 1/2 inch (12 mm) when tested
with a 16‑foot (4.8 m) straightedge, the irregular surface shall be
loosened and then refilled with the same kind of material as that used
in constructing the course and again rolled as required above.

Along places inaccessible to rollers, the subbase material shall be
tamped thoroughly with mechanical or hand tampers.

Sprinkling during rolling, if necessary, shall be in the amount and by
equipment approved by the Engineer.  Water shall not be added in such a
manner or quantity that free water will reach the underlying layer and
cause it to become soft.

**154-3.8 SURFACE TEST.**  After the course is completely compacted, the
surface shall be tested for smoothness and accuracy of grade and crown;
any portion found to lack the required smoothness or to fail in accuracy
of grade or crown shall be scarified, reshaped, recompacted, and
otherwise manipulated as the Engineer may direct until the required
smoothness and accuracy re obtained.  The finished surface shall not
vary more than 1/2 inch (12 mm) when tested with a 16‑foot (4.8 m)
straightedge applied parallel with, and at right angles to, the
centerline.

**154-3.9 THICKNESS.**  The thickness of the completed subbase course
shall be determined by depth tests or sample holes taken at intervals so
each test shall represent no more than 500 square yards (420 square
meters).  When the deficiency in thickness is more than 1/2 inch (12
mm), the Contractor shall correct such areas by scarifying, adding
satisfactory mixture, rolling, sprinkling, reshaping, and finishing in
accordance with these specifications.  The Contractor shall replace at
his/her expense the subbase material where borings are taken for test
purposes.

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

> **The use of survey for thickness determination is permitted.**

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

**154-3.10 PROTECTION.**  Work on subbase course shall not be conducted
during freezing temperature nor when the subgrade is wet.  When the
subbase material contains frozen material or when the underlying course
is frozen, the construction shall be stopped.

**154-3.11 MAINTENANCE.**  Following the final shaping of the material,
the subbase shall be maintained throughout its entire length by the use
of standard motor graders and rollers until, in the judgment of the
Engineer, the subbase meets all requirements and is acceptable for the
construction of the next course.

METHOD OF MEASUREMENT

**154-4.1** The yardage of subbase course to be paid for shall be the
number of cubic yards (cubic meters) of subbase course material placed,
compacted, and accepted in the completed course.  The quantity of
subbase course material shall be measured in final position based upon
depth tests or cores taken as directed by the Engineer, or at the rate
of 1 depth test for each 500 square yards (420 square meters) of subbase
course, or by means of average end areas on the complete work computed
from elevations to the nearest 0.01 foot (3 mm).  On individual depth
measurements, thicknesses more than 1/2 inch (12 mm) in excess of that
shown on the plans shall be considered as the specified thickness plus
1/2 inch (12 mm) in computing the yardage for payment.  Subbase
materials shall not be included in any other excavation quantities.

BASIS OF PAYMENT

**154-5.1**  Payment shall be made at the contract unit price per cubic
yard (cubic meter) for subbase course.  This price shall be full
compensation for furnishing all materials; for all preparation, hauling,
and placing of these materials; and for all labor, equipment, tools, and
incidentals necessary to complete the item.

Payment will be made under:

Item P‑154‑5.1 Subbase Course---per cubic yard (cubic meter)

TESTING REQUIREMENTS

ASTM C 136 Sieve Analysis of Fine and Coarse Aggregates

ASTM D 422 Particle Size Analysis of Soils

ASTM D 698 Moisture‑Density Relations of Soils and Soil‑Aggregate
Mixtures Using 5.5 lb (2.49 kg) Rammer and 12‑in (305 mm) Drop

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

ASTM D 1557 Test for Laboratory Compaction Characteristics of Soil Using
Modified Effort

> ASTM D 2922 Density of Soil in Place by the Nuclear Density Method

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

**END OF ITEM P-154**

**Intentionally Left Blank**

### **ITEM P-155 LIME-TREATED SUBGRADE**

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

> **The soluble sulfate contents of the soils should be checked during
> design to determine if stabilization with lime, cement, and/or fly ash
> can react and induce heave. Contents as low as 0.5% soluble sulfates
> have resulted in the formation of ettringnite and thaumasite, which
> expands when available water is present.**

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

DESCRIPTION

**155-1.1**  This item shall consist of constructing one or more courses
of a mixture of soil, lime, and water in accordance with this
specification, and in conformity with the lines, grades, thicknesses,
and typical cross sections shown on the plans.

MATERIALS

**155-2.1 HYDRATED LIME.**  All lime shall be manufactured high-calcium
quicklime, low-calcium quicklime, or hydrated lime, as defined by ASTM C
51, and conform to the requirements of ASTM C 977. By product lime or
any form of calcium oxide (CaO), calcium hydroxide (Ca(OH)2), magnesium
oxide (MgO) or magnesium hydroxide (Mg(OH)2), alone or in combination,
that are not directly produced from quicklime produced from calcining
limestone, shall not be permitted.

**155-2.2 COMMERCIAL LIME SLURRY.**  Commercial lime slurry shall be a
pumpable suspension of solids in water.  The water or liquid portion of
the slurry shall not contain dissolved material in sufficient quantity
naturally injurious or objectionable for the purpose intended.  The
solids portion of the mixture, when considered on the basis of
\`\`solids content,\'\' shall consist principally of hydrated lime of a
quality and fineness sufficient to meet the following requirements as to
chemical composition and residue.

**a. Chemical Composition.**  The \`\`solids content\'\' of the lime
slurry shall consist of a minimum of 70%, by weight, of calcium and
magnesium oxides.

**b. Residue.**  The percent by weight of residue retained in the
\`\`solids content\'\' of lime slurry shall conform to the following
requirements:

Residue retained on a No. 6 (3360 micron) sieve ‑‑‑‑‑‑ Max. 0.0%

Residue retained on a No. 10 (2000 micron) sieve ‑‑‑‑‑ Max. 1.0%

Residue retained on a No. 30 (590 micron) sieve ‑‑‑‑‑‑ Max. 2.5%

**c. Grade.**  Commercial lime slurry shall conform to one of the
following two grades:

Grade 1.  The \`\`dry solids content\'\' shall be at least 31%

by weight, of the slurry.

Grade 2.  The \`\`dry solids content\'\' shall be at least 35%,

by weight, of the slurry.

**155-2.3 WATER.**  Water used for mixing or curing shall be reasonably
clean and free of oil, salt, acid, alkali, sugar, vegetable, or other
substances injurious to the finished product.  Water shall be tested in
accordance with and shall meet the suggested requirements of AASHTO T
26.  Water known to be of potable quality may be used without test.

**155-2.4 SOIL.**  The soil for this work shall consist of materials on
the site or selected materials from other sources and shall be uniform
in quality and gradation, and shall be approved by the Engineer.  The
soil shall be free of roots, sod, weeds, and stones larger than 2‑1/2
inches (60 mm).

COMPOSITION

**155-3.1 LIME.**  Lime shall be applied at the rate specified on the
plans for the depth of subgrade treatment shown.

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

> **This paragraph should specify the amount of lime to be incorporated
> either by percent of dry weight or by the desired performance
> criteria. Samples for determination of lime content should be from
> material, which will represent the final placement of material to be
> treated. The Lime content should be sufficient to lower the Liquid
> Limit to less than 30 and the Plasticity Index to less than 10.**
>
> **The project specifications should address the percent of lime to be
> used in the project. If the exact percent is not specified, the
> contractor should be provided with some means to estimate (for bidding
> purposes) the quantity of lime to be used in the project.**

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

**155-3.2 TOLERANCES.**  At final compaction, the lime and water content
for each course of subgrade treatment shall conform to the following
tolerances:

  ------------------------------------ ----------------------------------
  **Material**                         **Tolerance**

                                       

  Lime                                 \+ 0.5%

  Water                                \+ 2%, ‑0%
  ------------------------------------ ----------------------------------

WEATHER LIMITATIONS

**155-4.1 WEATHER LIMITATION.**  The lime‑treated subgrade shall not be
mixed while the atmospheric temperature is below 40 F (4 C) or when
conditions indicate that temperatures may fall below 40 F (4 C) within
24 hours, when it is foggy or rainy, or when soil or subgrade is frozen.

EQUIPMENT

**155-5.1 EQUIPMENT.**  The equipment required shall include all
equipment necessary to complete this item such as: grading and
scarifying equipment, a spreader for the lime or lime slurry, mixing or
pulverizing equipment, sheepsfoot and pneumatic or vibrating rollers,
sprinkling equipment, and trucks.

CONSTRUCTION METHODS

**155-6.1 GENERAL.**  It is the primary requirement of this
specification to secure a completed subgrade containing a uniform lime
mixture, free from loose or segregated areas, of uniform density and
moisture content, well bound for its full depth, and with a smooth
surface suitable for placing subsequent courses.  It shall be the
responsibility of the Contractor to regulate the sequence of his/her
work, to use the proper amount of lime, maintain the work, and rework
the courses as necessary to meet the above requirements.

Prior to beginning any lime treatment, the subgrade shall be constructed
and brought to grade as specified in Item P‑152 \`\`Excavation and
Embankment\'\' and shall be shaped to conform to the typical sections,
lines, and grades as shown on the plans.  The material to be treated
shall then be excavated to the secondary grade (proposed bottom of lime
treatment) and removed or windrowed to expose the secondary grade.  Any
wet or unstable materials below the secondary grade shall be corrected,
as directed by the Engineer, by scarifying, adding lime, and compacting
until it is of uniform stability.  The excavated material shall then be
spread to the desired cross section.

If the Contractor elects to use a cutting and pulverizing machine that
will remove the subgrade material accurately to the secondary grade and
pulverize the material at the same time, he will not be required to
expose the secondary grade nor windrow the material.  However, the
Contractor shall be required to roll the subgrade, as directed by the
Engineer, and correct any soft areas that this rolling may reveal before
using the pulverizing machine.  This method will be permitted only where
a machine is provided which will ensure that the material is cut
uniformly to the proper depth and which has cutters that will plane the
secondary grade to a smooth surface over the  entire width of the cut. 
The machine must give visible indication at all times that it is cutting
to the proper depth.

**155-6.2 APPLICATION.**  Lime shall be spread only on that area where
the first mixing operations can be completed during the same working
day.  The application and mixing of lime with the soil shall be
accomplished by the methods hereinafter described as \`\`Dry Placing\'\'
or \`\`Slurry Placing.\'\'  When hydrated lime is specified, the
Contractor may use either method.

**a. Dry Placing.**  The lime shall be spread uniformly over the top of
the subgrade by an approved screw‑type spreader box or other approved
spreading equipment.  The amount of lime spread shall be the amount
required for mixing to the specified depth that will result in the
percentage determined in the job mix formula.

The lime shall be distributed in such manner that scattering by wind
will be minimal.  Lime shall not be applied when wind conditions, in the
opinion of the Engineer, are detrimental to a proper application.  A
motor grader shall not be used to spread the lime.  The material shall
be sprinkled, as directed by the Engineer, until the proper moisture
content has been reached.

**b. Slurry Placing.**  The lime shall be mixed with water in trucks
with approved distributors and applied as a thin water suspension or
slurry.  Commercial lime slurry shall be applied with a lime percentage
not less than that applicable for the grade used.  The distribution of
lime shall be attained by successive passes over a measured section of
subgrade until the proper amount of lime has been spread.  The amount of
lime spread shall be the amount required for mixing to the specified
depth that will result in the percentage determined in the job mix
formula.  The distributor truck shall continually agitate the slurry to
keep the mixture uniform.

**155-6.3 MIXING.**  The mixing procedure shall be the same for \`\`Dry
Placing\'\' or \`\`Slurry Placing\'\' as hereinafter described:

**a. First Mixing.**  The full depth of the treated subgrade shall be
mixed with an approved mixing machine.  Lime shall not be left exposed
for more than 6 hours.  The mixing machine shall make two coverages. 
Water shall be added to the subgrade during mixing to provide a moisture
content above the optimum moisture of the material and to ensure
chemical action of the lime and subgrade.  After mixing, the subgrade
shall be lightly rolled to seal the surface and help prevent evaporation
of moisture.  The water content of the subgrade mixture shall be
maintained at a moisture content above the optimum moisture content for
a minimum of 48 hours or until the material becomes friable.  During the
curing period, the material shall be sprinkled as directed.  During the
interval of time between application and mixing, lime that has been
exposed to the open air for 6 hours or more, or to excessive loss due to
washing or blowing will not be accepted for payment.

**b. Final Mixing.**  After the required curing time, the material shall
be uniformly mixed by approved methods.  If the mixture contains clods,
they shall be reduced in size by blading, discing, harrowing,
scarifying, or the use of other approved pulverization methods so that
the remainder of the clods shall meet the following requirements when
tested dry by laboratory sieves:

  ---------------------------------------------------- ------------------
                                                       **Percent**

  Minimum of clods passing 1-1/2\\ inch sieve          100

  Minimum of clods passing No. 4 sieve                 60
  ---------------------------------------------------- ------------------

**155-6.4 COMPACTION.**  Compaction of the mixture shall begin
immediately after final mixing.  The material shall be aerated or
sprinkled as necessary to provide optimum moisture.  The field density
of the compacted mixture shall be at least 93 percent of the maximum
density of laboratory specimens prepared from samples taken from the
material in place.  The specimens shall be compacted and tested in
accordance with ASTM D 698.  The in‑place field density shall be
determined in accordance with ASTM D 1556 or ASTM D 2922.  Any mixture
that has not been compacted shall not be left undisturbed for more than
30 minutes.  The moisture content of the mixture at the start of
compaction shall not be below nor more than 2 percentage points above
the optimum moisture content.  The optimum moisture content shall be
determined in accordance with ASTM D 698 and shall be less than that
amount which will cause the mixture to become unstable during compaction
and finishing.

The material shall be sprinkled and rolled as directed by the Engineer. 
All irregularities, depressions, or weak spots that develop shall be
corrected immediately by scarifying the areas affected, adding or
removing material as required, and reshaping and recompacting by
sprinkling and rolling.  The surface of the course shall be maintained
in a smooth condition, free from undulations and ruts, until other work
is placed thereon or the work is accepted.

In addition to the requirements specified for density, the full depth of
the material shown on the plans shall be compacted to the extent
necessary to remain firm and stable under construction equipment.  After
each section is completed, tests will be made by the Engineer.  If the
material fails to meet the density requirements, it shall be reworked to
meet these requirements.  Throughout this entire operation, the shape of
the course shall be maintained by blading, and the surface upon
completion shall be smooth and shall conform with the typical section
shown on the plans and to the established lines and grades.  Should the
material, due to any reason or cause, lose the required stability,
density, and finish before the next course is placed or the work is
accepted, it shall be recompacted and refinished at the sole expense of
the Contractor.

When nuclear gages are to be used for density determination, testing
shall be done in accordance with Section 120.

**155-6.5 FINISHING AND CURING.**  After the final layer or course of
lime‑treated subgrade has been compacted, it shall be brought to the
required lines and grades in accordance with the typical sections.  The
completed section shall then be finished by rolling, as directed, with a
pneumatic or other suitable roller sufficiently light to prevent hair
cracking.  The finished surface shall not vary more than 3/8 inch (9 mm)
when tested with a 16‑foot (4.8 meter) straightedge applied parallel
with and at right angles to the pavement centerline.  Any variations in
excess of this tolerance shall be corrected by the Contractor, at
his/her own expense, in a manner satisfactory to the Engineer.

The completed section shall be moist‑cured for a minimum of 7 days
before further courses are added or any traffic is permitted, unless
otherwise directed by the Engineer.  Subsequent courses shall be applied
within 14 days after the lime‑treated subgrade is cured.

**155-6.6 THICKNESS.**  The thickness of the lime‑treated subgrade shall
be determined by depth tests or cores taken at intervals so that each
test shall represent no more than 300 square yards (250 square meters). 
When the base deficiency is more than 1/2 inch (12 mm), the Contractor
shall correct such areas in a manner satisfactory to the Engineer.  The
Contractor shall replace, at his/her expense, the base material where
borings are taken for test purposes.

**155-6.7 MAINTENANCE.**  The Contractor shall maintain, at his/her own
expense, the entire lime‑treated subgrade in good condition from the
start of work until all the work has been completed, cured, and accepted
by the Engineer.

METHOD OF MEASUREMENT

**155-7.1** The yardage of lime-treated subgrade to be paid for shall be
the number of square yards (square meters) completed and accepted.

**155-7.2** The amount of lime to be paid for shall be the number of
tons (kg) of Hydrated Lime, or the calculated equivalent thereof, used
as authorized. \"Calculated Equivalent\" will be determined by the
Engineer as follows:

**a.** Hydrated lime delivered to the project in dry form will be
measured according to the actual tonnage either spread on the subgrade
or batched on site into a slurry, whichever is applicable.

**b.** Lime delivered to the project in slurry form will be paid for on
the basis of certified chemical composition tickets and batch weight
tickets. The owner shall reserve the right to have the dry lime content
verified by an independent testing laboratory. If the chemical
composition is reported on the basis of Pebble Quicklime, the equivalent
hydrated lime will be determined in accordance with paragraph c. below.

**c.** If Pebble Quicklime is delivered to the project in dry form it
will be measured for payment on the basis of the following formula:

Total Quicklime (CaO)(Tons) x %Purity x 1.32 Factor + Total Quicklime
(CaO)(Tons) x % Impurities x 1.00 Factor = Equivalent Hydrated Lime
Ca(OH)~2~(Tons).

The foregoing will apply whether the quicklime is spread dry (if
allowed) or batched into a slurry.

BASIS OF PAYMENT

**155-8.1**  Payment shall be made at the contract unit price per square
yard (square meter) for the lime‑treated subgrade of the thickness
specified.  The price shall be full compensation for furnishing all
material, except the lime, and for all preparation, delivering, placing
and mixing these materials, and all labor, equipment, tools and
incidentals necessary to complete this item.

**155-8.2**  Payment shall be made at the contract unit price per pound
(kg) of lime.  This price shall be full compensation for furnishing this
material; for all delivery, placing and incorporation of this material;
and for all labor, equipment, tools, and incidentals necessary to
complete this item.

Payment will be made under:

Item P‑155‑8.1 Lime‑treated subgrade---per square yard (square meter)

Item P‑155‑8.2 Lime---per pound (kg)

TESTING REQUIREMENTS

ASTM D 698 Moisture‑Density Relations of Soils and Soil‑Aggregate
Mixtures Using 5.5 lb (2.49 kg) Rammer and 12‑in. (305 mm) Drop

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

> ASTM D 2922 Density of Soil in Place by the Nuclear Density Method

AASHTO T 26 Quality of Water to be Used in Concrete

MATERIAL REQUIREMENTS

ASTM C 977 Quicklime and Hydrated Lime for Soil Stabilization

**END OF ITEM P-155**

**Intentionally Left Blank**

### **ITEM P-156 TEMPORARY AIR AND WATER POLLUTION, SOIL EROSION, AND SILTATION CONTROL**

DESCRIPTION

**156-1.1**  This item shall consist of temporary control measures as
shown on the plans or as ordered by the Engineer during the life of a
contract to control water pollution, soil erosion, and siltation through
the use of berms, dikes, dams, sediment basins, fiber mats, gravel,
mulches, grasses, slope drains, and other erosion control devices or
methods.

The temporary erosion control measures contained herein shall be
coordinated with the permanent erosion control measures specified as
part of this contract to the extent practical to assure economical,
effective, and continuous erosion control throughout the construction
period.

Temporary control may include work outside the construction limits such
as borrow pit operations, equipment and material storage sites, waste
areas, and temporary plant sites.

MATERIALS

**156-2.1 GRASS.**  Grass that will not compete with the grasses sown
later for permanent cover shall be a quick‑growing species (such as
ryegrass, Italian ryegrass, or cereal grasses) suitable to the area
providing a temporary cover.

**156-2.2 MULCHES.** Mulches may be hay, straw, fiber mats, netting,
bark, wood chips, or other suitable material reasonably clean and free
of noxious weeds and deleterious materials.

**156-2.3 FERTILIZER.**  Fertilizer shall be a standard commercial grade
and shall conform to all Federal and state regulations and to the
standards of the Association of Official Agricultural Chemists.

**156-2.4 SLOPE DRAINS.**  Slope drains may be constructed of pipe,
fiber mats, rubble, portland cement concrete, bituminous concrete, or
other materials that will adequately control erosion.

**156-2.5 OTHER.**  All other materials shall meet commercial grade
standards and shall be approved by the Engineer before being
incorporated into the project.

CONSTRUCTION REQUIREMENTS

**156-3.1 GENERAL.**  In the event of conflict between these
requirements and pollution control laws, rules, or regulations of other
Federal, state, or local agencies, the more restrictive laws, rules, or
regulations shall apply.

The Engineer shall be responsible for assuring compliance to the extent
that construction practices, construction operations, and construction
work are involved.

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

> **Some states, municipalities, and pollution control authorities have
> very specific regulations for air and water pollution controls.  These
> may include requirements for:**
>
> **Use of smoke density charts.**
>
> **Measurement of weight and density (micrograms per cubic meter of
> air) of suspended particulate.**
>
> **Permissible weights of emission in pounds per hour (kilograms per
> hour) versus pounds per hour (kilograms per hour) of material
> processed.**
>
> **Open burning.**
>
> **Erosion control measures.**

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

**156-3.2 SCHEDULE.**  Prior to the start of construction, the
Contractor shall submit schedules for accomplishment of temporary and
permanent erosion control work, as are applicable for clearing and
grubbing; grading; construction; paving; and structures at
watercourses.  The Contractor shall also submit a proposed method of
erosion and dust control on haul roads and borrow pits and a plan for
disposal of waste materials.  Work shall not be started until the
erosion control schedules and methods of operation for the applicable
construction have been accepted by the Engineer.

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

> **Several methods of controlling dust and other air pollutants
> include:**
>
> **Exposing the minimum area of erodible earth.**
>
> **Applying temporary mulch with or without seeding.**
>
> **Using water sprinkler trucks.**
>
> **Using covered haul trucks.**
>
> **Using dust palliatives or penetration asphalt on haul roads.**
>
> **Using plastic sheet coverings.**

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

**156-3.3 AUTHORITY OF ENGINEER.**  The Engineer has the authority to
limit the surface area of erodible earth material exposed by clearing
and grubbing, to limit the surface area of erodible earth material
exposed by excavation, borrow and fill operations, and to direct the
Contractor to provide immediate permanent or temporary pollution control
measures to minimize contamination of adjacent streams or other
watercourses, lakes, ponds, or other areas of water impoundment.

**156-3.4 CONSTRUCTION DETAILS.**  The Contractor will be required to
incorporate all permanent erosion control features into the project at
the earliest practicable time as outlined in the accepted schedule. 
Except where future construction operations will damage slopes, the
Contractor shall perform the permanent seeding and mulching and other
specified slope protection work in stages, as soon as substantial areas
of exposed slopes can be made available.  Temporary erosion and
pollution control measures will be used to correct conditions that
develop during construction that were not foreseen during the design
stage; that are needed prior to installation of permanent control
features; or that are needed temporarily to control erosion that
develops during normal construction practices, but are not associated
with permanent control features on the project.

Where erosion is likely to be a problem, clearing and grubbing
operations should be scheduled and performed so that grading operations
and permanent erosion control features can follow immediately thereafter
if the project conditions permit; otherwise, temporary erosion control
measures may be required between successive construction stages.

The Engineer will limit the area of clearing and grubbing, excavation,
borrow, and embankment operations in progress, commensurate with the
Contractor\'s capability and progress in keeping the finish grading,
mulching, seeding, and other such permanent control measures current in
accordance with the accepted schedule.  Should seasonal limitations make
such coordination unrealistic, temporary erosion control measures shall
be taken immediately to the extent feasible and justified.

In the event that temporary erosion and pollution control measures are
required due to the Contractor\'s negligence, carelessness, or failure
to install permanent controls as a part of the work as scheduled or are
ordered by the Engineer, such work shall be performed by the Contractor
at his/her own expense.

The Engineer may increase or decrease the area of erodible earth
material to be exposed at one time as determined by analysis of project
conditions.

The erosion control features installed by the Contractor shall be
acceptably maintained by the Contractor during the construction period.

Whenever construction equipment must cross watercourses at frequent
intervals, and such crossings will adversely affect the sediment levels,
temporary structures should be provided.

Pollutants such as fuels, lubricants, bitumen, raw sewage, wash water
from concrete mixing operations, and other harmful materials shall not
be discharged into or near rivers, streams, and impoundments or into
natural or manmade channels leading thereto.

METHOD OF MEASUREMENT

**156-4.1**  Temporary erosion and pollution control work required which
is not attributed to the Contractor\'s negligence, carelessness, or
failure to install permanent controls will be performed as scheduled or
ordered by the Engineer.  Completed and accepted work will be measured
as follows:

**a.**  Temporary seeding and mulching will be measured by the square
yard (square meter).

**b.**  Temporary slope drains will be measured by the linear foot
(meter).

**c.**  Temporary benches, dikes, dams, and sediment basins will be
measured by the cubic yard (cubic meter) of excavation performed,
including necessary cleaning of sediment basins, and the cubic yard
(cubic meter) of embankment placed at the direction of the Engineer, in
excess of plan lines and elevations.

**d.**  All fertilizing will be measured by the ton (kilogram).

**156-4.2**  Control work performed for protection of construction areas
outside the construction limits, such as borrow and waste areas, haul
roads, equipment and material storage sites, and temporary plant sites,
will not be measured and paid for directly but shall be considered as a
subsidiary obligation of the Contractor with costs included in the
contract prices bid for the items to which they apply.

BASIS OF PAYMENT

**156-5.1**  Accepted quantities of temporary water pollution, soil
erosion, and siltation control work ordered by the Engineer and measured
as provided in paragraph 156‑4.1 will be paid for under:

Item P‑156‑5.1 Temporary seeding and mulching---per square yard (square

meter)

Item P‑156‑5.2 Temporary slope drains---per linear foot (meter)

Item P‑156‑5.3 Temporary benches, dikes, dams and sediment basins---per

cubic yard (cubic meter)

Item P‑156‑5.4 Fertilizing---per ton (kilogram)

Where other directed work falls within the specifications for a work
item that has a contract price, the units of work shall be measured and
paid for at the contract unit price bid for the various items.

Temporary control features not covered by contract items that are
ordered by the Engineer will be paid for in accordance with Section
90‑05.

**END OF ITEM P-156**

### **ITEM P-157 CEMENT KILN DUST (CKD) TREATED SUBGRADE**

DESCRIPTION

**157-1.1** This item shall consist of constructing one or more courses
of a mixture of soil, cement kiln dust, and water in accordance with
this specification, and in conformity with the lines, grades, thickness,
and typical cross sections shown on the plans.

MATERIALS

**157-2.1 CEMENT KILN DUST**. Cement kiln dust shall contain a minimum
of 40% CaO and be capable of providing the soil modification specified
for this project. Cement Kiln Dust from the
(\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_) Cement Plant(s) is(are) a
pre-approved source for cement kiln dust for this project. All other
sources shall be identified and approved in advance of stabilization
operations in order that laboratory tests can be completed prior to
commencing work.

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

> **NOTE TO ENGINEER: Enter the known acceptable sources of cement kiln
> dust. If no sources have been pre-identified, delete the 2nd
> sentence.**

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

Cement kiln dust shall be stored and handled in closed waterproof
containers until immediately before distribution. Temporary storage
(less than 12 hours) of cement kiln dust in open pits may be allowed
provided that wetting of the cement kiln dust by rain or subgrade
moisture is not allowed. Cement kiln dust exposed to moisture prior to
mixing with soils shall be discarded.

**157-2.3 WATER.** Water used for mixing or curing shall be reasonably
clean and free of oil, salt, acid, alkali, sugar, vegetable, or other
substances injurious to the finished product. Water shall be tested in
accordance with and shall meet the suggested requirements of AASHTO T
26. Water known to be of potable quality may be used without testing.

**157-2.4 SOIL.** The soil for this work shall consist of on site
materials or selected materials from other sources and shall be uniform
in quality and gradation, and shall be approved by the Engineer. The
soil shall be free of roots, sod, weeds, and stones larger than 2 1/2
inches and have a sulfate content of less than 1.0%.

COMPOSITION

**157-3.1 CEMENT KILN DUST**. Samples for evaluation of cement kiln dust
effectiveness shall be taken from each layer of CKD treated subgrade
after it has been properly mixed and moisture conditioned. Cement kiln
dust shall be added until a Plasticity Index of less than (\_\_\_\_) is
reached. When the cement kiln dust treated material is used as a base
material, it shall be added until minimum CBR of (\_\_\_\_) and/or a
7-day accelerated (100°F) compressive strength (Section 8.5 of ASTM
C-593) of (\_\_\_\_\_\_) psi is achieved. Payment will be based on the
amount of cement kiln dust required to obtain the minimum soil
properties specified.

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

> **NOTE TO ENGINEER: Enter the desired properties for the treated
> material.**

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

**157-3.2 TOLERANCES.** At final compaction, the CKD and water content
for each course of subgrade treatment shall conform to the following
tolerances:

> [Material/Properties Target Tolerance Specifications]{.underline}
>
> Cement Kiln Dust (\_\_\_\_)% 0 to +2% % Total Dry Materials
>
> Moisture Content Optimum 0% to 6% ASTM D-1557
>
> Plastic Index \< (\_\_\_\_) None ASTM D-4318

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

> **NOTE TO ENGINEER: Enter the appropriate values as identified in
> paragraph 3.1**

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

WEATHER LIMITATIONS

**157-4.1 WEATHER LIMITATION.** The cement kiln dust-treated subgrade
shall not be mixed while the atmospheric temperature is below 40 F or
when conditions indicate that temperatures may fall below 40 F within 24
hours, or when soil or subgrade is frozen.

EQUIPMENT

**157-5.1 EQUIPMENT**. The equipment required shall include all
equipment necessary to complete this item such as: grading and
scarifying equipment, a spreader for the cement kiln dust, mixing or
pulverizing equipment, sheepsfoot and pneumatic or vibrating rollers,
sprinkling equipment, and trucks.

CONSTRUCTION METHODS

**157-6.1 GENERAL.** It is the primary requirement of this specification
to secure a completed subgrade containing a uniform cement kiln
dust/soil mixture, free from loose or segregated areas, of uniform
density and moisture content, well mixed for its full depth, and with a
smooth surface suitable for placing subsequent courses. It shall be the
responsibility of the Contractor to regulate the sequence of his/her
work, to use the proper amount of cement kiln dust, maintain the work,
and rework the courses as necessary to meet the above requirements.

Prior to beginning any cement kiln dust treatment the subgrade shall be
constructed and brought to grade as specified in Item P 152
\`\`Excavation and Embankment\'\' and shall be shaped to conform to the
typical sections, lines, and grades as shown on the plans. Any wet or
unstable areas shall be corrected, as directed by the Engineer, by
over-excavating, scarifying, adding cement kiln dust, and/or compacting
until it is of uniform stability. The Contractor shall be required to
roll the subgrade, as directed by the Engineer, and correct any soft
areas that this rolling may reveal.

**157-6.2 APPLICATION.** Cement kiln dust shall be spread only on that
area where the first mixing operations can be completed during the same
working day. The application and mixing of cement kiln dust with the
soil shall be accomplished by the methods hereinafter described as \"Dry
Placing\".

**a. Dry Placing.** The cement kiln dust shall be spread uniformly over
the top of the subgrade by an approved screw type spreader box or other
approved spreading equipment. The amount of cement kiln dust spread
shall be the amount required for mixing to the specified depth which
will result in the percentage determined in the job mix formula.

The cement kiln dust shall be distributed in such a manner that
scattering by wind will be minimal. Cement kiln dust shall not be
applied when wind conditions, in the opinion of the Engineer, are
detrimental to a proper application. The CKD/soil mixture shall be
moisture conditioned, as directed by the Engineer, until the proper
moisture content has been reached.

**157-6.3 MIXING.** The mixing procedure shall be the same for \"Dry
Placing\" as hereinafter described:

The full depth of the treated subgrade shall be mixed with a rotary
pulvamixer, disc and field cultivator or, other suitable methods as
approved by the Engineer. Cement kiln dust shall not be left exposed for
more than 1 hour after distribution.

Required moisture contents shall be established by the Engineer based on
laboratory tests with the site soils at the specified cement kiln dust
percent to be used for soil modification. Final moisture content of the
mix, immediately prior to compaction shall be determined in accordance
with ASTM C-593 (Modified Proctor) and shall not be less than the
optimum moisture content or more than 6 percent over optimum.

If the soil cement kiln dust mixture contains clods greater than 1-1/2
inch in size, they shall be reduced in size by additional pulverization.

As a minimum, one soil sample will be obtained and tested for each 25
tons of CKD incorporated. Testing shall include Plastic Index
Determination (ASTM D-4318) and 7-day accelerated compressive strengths
(Section 8 ASTM C-593).

Areas that fall below specified values will need to be reworked, as
directed by the Engineer.

**157-6.4 COMPACTION.** Compaction of the soil/cement kiln dust mixture
shall be delayed for a minimum of 24 hours after mixing the cement kiln
dust into the subgrade. The field density of the compacted mixture shall
be at least 90 percent of the maximum density as determined by ASTM
D-1557. The in-place field density shall be determined in accordance
with ASTM D-1556 or ASTM D 2167. Testing frequency shall be a minimum of
1 compaction test per 5000 square feet of stabilized base or as directed
by the Engineer.

All irregularities, depressions, or weak spots that develop shall be
corrected immediately by scarifying the areas affected, adding or
removing material as required, and reshaping and recompacting. The
surface of the course shall be maintained in a smooth condition, free
from undulations and ruts, until other work is placed thereon or the
work is accepted.

In addition to the requirements specified for density, the full depth of
the material shown on the plans shall be compacted to the extent
necessary to remain firm and stable under construction equipment. After
each section is completed, tests will be made by the Engineer. If the
material fails to meet the density requirements, it shall be reworked to
meet these requirements. Throughout this entire operation, the shape of
the course shall be maintained by blading, and the surface upon
completion shall be smooth and shall conform with the typical section
shown on the plans to the established lines and grades specified. Should
the material, due to any reason or cause, lose the required stability,
density, and finish before the next course is placed or the work is
accepted, it shall be recompacted and refinished at the sole expense of
the Contractor.

**157-6.5 FINISHING AND CURING.** After the final layer or course of
cement kiln dust treated subgrade has been compacted, it shall be
brought to the required lines and grades in accordance with the typical
sections. The finished surface shall not vary more than 3/8 inch when
tested with a 16-foot straightedge applied parallel with and at right
angles to the pavement centerline. Any variations in excess of this
tolerance shall be corrected by the Contractor, at his/her own expense,
in a manner satisfactory to the Engineer.

After the cement kiln dust treated course has been finished as specified
herein, the surface shall be protected against rapid drying by either of
the following methods for a period of not less than three days or until
the pavement section is placed.

**a.** Maintain in a thorough and continuously moist condition by
sprinkling.

**b.** Apply a 2-inch layer of earth on the compacted course and
maintain in a moist condition.

**157-6.6 THICKNESS.** The thickness of the cement kiln dust treated
subgrade shall be determined by depth tests or cores taken at intervals
so that each test shall represent no more than 300 square yards. When
the base deficiency is more than 1/2 inch, the Contractor shall correct
such areas in a manner satisfactory to the Engineer. The Contractor
shall replace, at his/her expense, the base material where borings are
taken for test purposes.

**157-6.7 MAINTENANCE.** The Contractor shall maintain, at his/her own
expense, the entire cement kiln dust treated subgrade in good condition
from the start of work until all the work has been completed, cured, and
accepted by the Engineer.

**157-6.8 HANDLING AND SAFETY.** The Contractor shall obtain from the
Supplier of the cement kiln dust the instructions for, proper safety and
handling of the cement kiln dust.

METHOD OF MEASUREMENT

**157-7.1** The amount of cement kiln dust treated subgrade to be paid
for shall be based on the number of square yards completed and accepted.

The amount of cement kiln dust utilized is based upon an application
rate of (\_\_\_) percent (by dry weight of soil).

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

> **NOTE TO ENGINEER: Enter the estimated percentage of kiln dust for
> the project.**

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

BASIS OF PAYMENT

**157-8.1** Payment shall be made at the contract unit price per square
yard for the cement kiln dust treated subgrade for the thickness
specified. The price shall be full compensation for furnishing all
material, and for all preparation, delivering, placing and mixing these
materials, and all labor, equipment, tools and incidentals necessary to
complete this item.

Payment will be made under:

Item P 157 8.1 Cement kiln dust treated subgrade per square yard

TESTING REQUIREMENTS

> ASTM D-1557 Moisture-Density Relations of Soils and Soil-Aggregate
> Mixtures Using 10 lb (7.1 kg) Rammer and 18-in. Drop

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

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

ASTM D-2922 Density of soil in place by the Nuclear Density Method.

AASHTO T 26 Quality of Water to be Used in Concrete

ASTM C-593 Fly Ash and other Pozzolans for use with Lime

> ASTM D-4318 Liquid Limit, Plastic Limit and Plastic Index of Soils

**END OF ITEM P-157**

### **ITEM P-158 FLY ASH TREATED SUBGRADE**

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

> **The soluble sulfate contents of the soils should be checked during
> design to determine if stabilization with lime, cement, and/or fly ash
> can react and induce heave. Contents as low as 0.5% soluble sulfates
> have resulted in the formation of ettringnite and thaumasite, which
> expands when available water is present.**
>
> **Soils should be tested by the Engineer prior to preparing the
> specification in order to assure that the fly ash can perform with the
> soils used in the project.**
>
> **At target design, the fly ash content should be such that the Liquid
> limit of the soils is reduced, the PH is increased, and an increase in
> bearing capacity is achieved.**

**\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
\* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \* \*
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DESCRIPTION

**158-1.1**  This item shall consist of constructing one or more courses
of a mixture of soil, fly ash, and water in accordance with this
specification, and in conformity with the lines, grades, thicknesses,
and typical cross sections shown on the plans.

MATERIALS

**158-2.1 FLY ASH.** Fly ash shall meet ASTM Specifications C-618,
Section 3.3 when sampled and tested in accordance with Sections 5,6, and
8, unless otherwise shown on the plans. Fly ash shall be of the Class
\"C\" designation containing a minimum of 25% CaO. The source of the ash
shall be identified and approved in advance of stabilization operations
in order that laboratory tests can be completed prior to commencing
work.

Fly Ash shall be stored and handled in closed weatherproof containers
until immediately before distribution. Temporary storage (less than 12
hours) of fly ash in open pits may be allowed provided that wetting of
the fly ash by rain or ground water is not allowed. Fly ash exposed to
moisture prior to mixing with soils shall be discarded.

**158-2.2 WATER.**  Water used for mixing or curing shall be reasonably
clean and free of oil, salt, acid, alkali, sugar, vegetable, or other
substances injurious to the finished product.  Water shall be tested in
accordance with and shall meet the suggested requirements of AASHTO T
26.  Water known to be of potable quality may be used without test.

**158-2.3 SOIL.**  The soil for this work shall consist of materials on
the site or selected materials from other sources and shall be uniform
in quality and gradation, and shall be approved by the Engineer.  The
soil shall be free of roots, sod, weeds, and stones larger than 2‑1/2
inches (60 mm).

COMPOSITION

**158-3.1 FLY ASH.**  Fly ash shall be applied at the rate specified on
the plans for the depth of subgrade treatment shown.

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> **This paragraph should specify the amount of fly ash to be
> incorporated either by percent of dry weight or by the desired
> performance criteria. Samples for determination of fly ash content
> should be from material, which will represent the final placement of
> material to be treated. The fly ash content should be sufficient at
> target design, such that the liquid limit of the soils is reduced, the
> PH is increased, and an increase in bearing capacity is achieved.**
>
> **The project specifications should address the percent of fly ash to
> be used in the project. If the exact percent is not specified, the
> contractor should be provided with some means to estimate (for bidding
> purposes) the quantity of fly ash to be used in the project.
> Experience has shown that 15% of dry weight has been sufficient.**

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**158-3.2 TOLERANCES.**  At final compaction, the fly ash and water
content for each course of subgrade treatment shall conform to the
following tolerances:

**Material Tolerance**

Fly Ash + 0.5%

Water + 2%, ‑0%

WEATHER LIMITATIONS

**158-4.1 WEATHER LIMITATION.** The fly ash treated subgrade shall not
be mixed while the atmospheric temperature is below 40 F (4 C) or when
conditions indicate that temperatures may fall below 40 F (4 C) within
24 hours, when it is foggy or rainy, or when soil or subgrade is frozen.

EQUIPMENT

**158-5.1 EQUIPMENT.**  The equipment required shall include all
equipment necessary to complete this item such as: grading and
scarifying equipment, a spreader for the fly ash, mixing or pulverizing
equipment, sheepsfoot and pneumatic or vibrating rollers, sprinkling
equipment, and trucks.

CONSTRUCTION METHODS

**158-6.1 GENERAL.**  It is the primary requirement of this
specification to secure a completed subgrade containing a uniform fly
ash mixture, free from loose or segregated areas, of uniform density and
moisture content, well bound for its full depth, and with a smooth
surface suitable for placing subsequent courses.  It shall be the
responsibility of the Contractor to regulate the sequence of his/her
work, to use the proper amount of fly ash, maintain the work, and rework
the courses as necessary to meet the above requirements.

Prior to beginning any fly ash treatment the subgrade shall be
constructed and brought to grade as specified in Item P‑152
\`\`Excavation and Embankment\'\' and shall be shaped to conform to the
typical sections, lines, and grades as shown on the plans.  The material
to be treated shall then be excavated to the secondary grade (proposed
bottom of fly ash treatment) and removed or windrowed to expose the
secondary grade.  Any wet or unstable materials below the secondary
grade shall be corrected, as directed by the Engineer, by scarifying,
adding fly ash, and compacting until it is of uniform stability.  The
excavated material shall then be spread to the desired cross section.

If the Contractor elects to use a cutting and pulverizing machine that
will remove the subgrade material accurately to the secondary grade and
pulverize the material at the same time, he will not be required to
expose the secondary grade nor windrow the material.  However, the
Contractor shall be required to roll the subgrade, as directed by the
Engineer, and correct any soft areas that this rolling may reveal before
using the pulverizing machine.  This method will be permitted only where
a machine is provided which will ensure that the material is cut
uniformly to the proper depth and which has cutters that will plane the
secondary grade to a smooth surface over the entire width of the cut. 
The machine must give visible indication at all times that it is cutting
to the proper depth.

**158-6.2 APPLICATION.**  Fly ash shall be spread only on that area
where the first mixing operations can be completed within 2 hours.  The
application and mixing of fly ash with the soil shall be accomplished by
the methods hereinafter described as \`\`Dry Placing.\'\' 

**a. Dry Placing.**  The fly ash shall be spread uniformly over the top
of the subgrade by an approved screw‑type spreader box or other approved
spreading equipment.  The amount of fly ash spread shall be the amount
required for mixing to the specified depth which will result in the
percentage determined in the job mix formula.

The fly ash shall be distributed in such manner that scattering by wind
will be minimal.  Fly ash shall not be applied when wind conditions, in
the opinion of the Engineer, are detrimental to a proper application.  A
motor grader shall not be used to spread the fly ash. 

**158-6.3 MIXING.**  The mixing procedure shall be the same for Dry
Placing as hereinafter described. The full depth of the treated subgrade
shall be mixed with a rotary pulvamixer that utilizes a direct hydraulic
drive. Fly ash shall not be left exposed for more than 30 minutes after
distribution. The mixing machine shall make two coverages. Water shall
be added through use of a pulvamixer equipped with a spray bar in the
mixing drum capable of applying sufficient quantities of water to
achieve the required moisture content of the soil-fly ash mixture. The
system shall be capable of being regulated to the degree as to maintain
moisture contents within the recommended range.

Required moisture contents shall be established by the Engineer based on
laboratory tests with the site soils and specific fly ash to be used for
the treatment. Final moisture content of the mix, immediately prior to
compaction shall be determined in accordance with ASTM D 698 and shall
not be below nor more than 2 percent above the optimum moisture content
for maximum density of the mix. If moisture contents exceed the
specified limits, additional fly ash may be added to lower the moisture
content to the required limits. Lowering moisture contents by aeration
following addition of the fly ash will not be permitted.

If the soil fly ash mixture contains clods greater than 1-1/2 inch in
size, they shall be reduced in size by additional pulverization.

**158-6.4 COMPACTION.**  Compaction of the soil-fly ash mixture shall
begin immediately after mixing of the fly ash and be completed within
two hours following incorporation of the fly ash. The field density of
the compacted mixture shall be at least 95 percent of the maximum
density of laboratory specimens prepared from samples taken from the
material in place. The specimens shall be compacted and tested in
accordance with ASTM D 698. The in-place density shall be determined in
accordance with ASTM D 1556, ASTM D 2167 or ASTM D 2922.

All irregularities, depressions, or weak spots, which develop, shall be
corrected immediately by scarifying the areas affected, adding or
removing material as required, and reshaping and re-compacting. The
surface of the course shall be maintained in a smooth condition, free
from undulations and ruts, until other work is placed thereon or the
work is accepted.

In addition to the requirements specified for density, the full depth of
the material shown on the plans shall be compacted to the extent
necessary to remain firm and stable under construction equipment.  After
each section is completed, tests will be made by the Engineer.  If the
material fails to meet the density requirements, it shall be reworked to
meet these requirements.  Throughout this entire operation, the shape of
the course shall be maintained by blading, and the surface upon
completion shall be smooth and shall conform with the typical section
shown on the plans and to the established lines and grades.  Should the
material, due to any reason or cause, lose the required stability,
density, and finish before the next course is placed or the work is
accepted, it shall be recompacted and refinished at the sole expense of
the Contractor.

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> **If nuclear density machines are to be used for density
> determination, the machines shall be calibrated in accordance with
> ASTM D 2922. The nuclear equipment shall be calibrated using blocks of
> materials with densities that extend through a range representative of
> the density of the proposed fly ash treated subgrade material. (See
> appendix 1 for additional guidance).**

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**158-6.5 FINISHING AND CURING.**  After the final layer or course of
the fly ash treated subgrade has been compacted, it shall be brought to
the required lines and grades in accordance with the typical sections.
The finished surface shall not vary more than 3/8 inch (9mm) when tested
with a 16-foot straightedge applied parallel with and at right angles to
the pavement centerline. Any variations in excess of this tolerance
shall be corrected by the Contractor, at his/her own expense, in a
manner satisfactory to the Engineer.

After the fly ash treated course has been finished as specified herein,
the surface shall be protected against rapid drying by either of the
following methods for a period of not less than three days or until the
pavement section is placed.

Maintain in a thorough and continuously moist condition by sprinkling.

Apply a 2-inch layer of earth of the completed course and maintain in a
moist condition.

**158-6.6 THICKNESS.**  The thickness of the fly ash treated subgrade
shall be determined by depth tests or cores taken at intervals so that
each test shall represent no more than 300 square yards (250 square
meters).  When the base deficiency is more than 1/2 inch (12 mm), the
Contractor shall correct such areas in a manner satisfactory to the
Engineer.  The Contractor shall replace, at his/her expense, the base
material where borings are taken for test purposes.

**158-6.7 MAINTENANCE.**  The Contractor shall maintain, at his/her own
expense, the entire fly ash treated subgrade in good condition from the
start of work until all the work has been completed, cured, and accepted
by the Engineer.

METHOD OF MEASUREMENT

**158-7.1**  The yardage of fly ash treated subgrade to be paid for
shall be the number of square yards (square meters) completed and
accepted.

**158-7.2**  The amount of fly ash to be paid for shall be the number of
pounds (kg) of fly ash used as authorized.

BASIS OF PAYMENT

**158-8.1**  Payment shall be made at the contract unit price per square
yard (square meter) for the fly ash treated subgrade of the thickness
specified.  The price shall be full compensation for furnishing all
material, except the fly ash, and for all preparation, delivering,
placing and mixing these materials, and all labor, equipment, tools and
incidentals necessary to complete this item.

**158-8.2**  Payment shall be made at the contract unit price per pound
(kg) of fly ash.  This price shall be full compensation for furnishing
this material; for all delivery, placing and incorporation of this
material; and for all labor, equipment, tools, and incidentals necessary
to complete this item.

Payment will be made under:

Item P‑158‑8.1 Fly ash treated subgrade---per square yard (square meter)

Item P‑158‑8.2 Fly ash---per pound (kg)

TESTING REQUIREMENTS

ASTM D 698 Moisture‑Density Relations of Soils and Soil‑Aggregate
Mixtures Using 5.5 lb (2.49 kg) Rammer and 12‑in. (305 mm) Drop

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

ASTM D 2167 Density and Unit Weight of Soil in Place by the
Rubber‑Ballon Method

AASHTO T 26 Quality of Water to be Used in Concrete

MATERIAL REQUIREMENTS

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

**END OF ITEM P-158**

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