**ITEM D‑752  CONCRETE CULVERTS, HEADWALLS, AND MISCELLANEOUS** DRAINAGE
STRUCTURES

DESCRIPTION

**752‑1.1**  This item shall consist of \[plain\]\[reinforced\] concrete
culverts, headwalls, and miscellaneous drainage structures constructed
in accordance with these specifications, at the specified locations and
conforming to the lines, grades, and dimensions shown on the plans or
required by the Engineer.

MATERIALS

**752-2.1 CONCRETE.**  **\[Plain\]\[reinforced\]** concrete shall meet
the requirements of Item P‑610.

CONSTRUCTION METHODS

**752-3.1 UNCLASSIFIED EXCAVATION.**

**a.**  Trenches and foundation pits for structures or structure
footings shall be excavated to the lines and grades or elevations shown
on the plans.  The excavation shall be of sufficient size to permit the
placing of the full width and length of the structure or structure
footings shown.  The elevations of the bottoms of footings, as shown on
the plans, shall be considered as approximate only; and the Engineer may
order, in writing, changes in dimensions or elevations of footings
necessary to secure a satisfactory foundation.

**b.**  Boulders, logs, or any other objectionable material encountered
in excavation shall be removed.  All rock or other hard foundation
material shall be cleaned of all loose material and cut to a firm
surface either level, stepped, or serrated, as directed by the
Engineer.  All seams or crevices shall be cleaned out and grouted.  All
loose and disintegrated rock and thin strata shall be removed.  When
concrete is to rest on a surface other than rock, special care shall be
taken not to disturb the bottom of the excavation, and excavation to
final grade shall not be made until just before the concrete or
reinforcing steel is to be placed.

**c.**  The Contractor shall do all bracing, sheathing, or shoring
necessary to perform and protect the excavation and the structure as
required for safety or conformance to governing laws.  The cost of
bracing, sheathing, or shoring shall be included in the unit price bid
for excavation.

**d.**  Unless otherwise provided, bracing, sheathing, or shoring
involved therewith shall be removed by the Contractor after the
completion of the structure.  Removal shall be effected in a manner that
will not disturb or mar finished concrete.  The cost of removal shall be
included in the unit price bid for excavation.

**e.**  After each excavation is completed, the Contractor shall notify
the Engineer to that effect, and concrete or reinforcing steel shall be
placed after the Engineer has approved the depth of the excavation and
the character of the foundation material.

**752-3.2 BACKFILLING.**

**a.**  After a structure has been completed, backfilling with approved
material shall be accomplished by applying the fill in horizontal layers
not to exceed 8 inches (200 mm) in loose depth, and compacted. The field
density of the compacted material shall be at least 90 percent of the
maximum density for cohesive soils and 95 percent of the maximum density
for noncohesive soils.  The maximum density shall be determined in
accordance with ASTM D 698.  The field density shall be determined in
accordance with ASTM D 1556.

**b.**  No backfilling shall be placed against any structure until
permission is given by the Engineer.  In the case of concrete, such
permission shall not be given until the concrete has been in place 7
days, or until tests made by the laboratory under the supervision of the
Engineer establish that the concrete has attained sufficient strength to
provide a factor of safety against damage or strain in withstanding any
pressure created by the backfill or the methods used in placing it.

**c.**  Fill placed around concrete culverts shall be deposited on both
sides at the same time and to approximately the same elevation.  Care
shall be taken to prevent any wedging action against the structure, and
all slopes bounding or within the areas to be backfilled shall be
stepped or serrated to prevent wedge action.

**d.**  Backfill will not be measured for direct payment.  Performance
of this work under the contract is not payable directly but shall be
considered as a subsidiary obligation of the Contractor, covered under
the contract unit price for \`\`unclassified excavation for
structures.\'\'

**752-3.3 WEEP HOLES.**  Weep holes shall be constructed as shown on the
plans.

**752-3.4 CLEANING AND RESTORATION OF SITE.**  After the backfill is
completed, the Contractor shall dispose of all surplus material, dirt,
and rubbish from the site.  Surplus dirt may be deposited in embankment,
shoulders, or as ordered by the Engineer.  The Contractor shall restore
all disturbed areas to their original condition.

After all work is completed, the Contractor shall remove all tools and
equipment, leaving the entire site free, clear, and in good condition.

METHOD OF MEASUREMENT

**752-4.1**   The quantity of unclassified excavation for structures to
be paid for shall be the number of cubic yards (cubic meters), measured
in original position, of material excavated in accordance with the
plans, or as directed by the Engineer; but in no case shall any yardage
be included in the measurement for payment which is outside of a volume
bounded by vertical planes 18 inches (45 cm) outside of and parallel to
the neat lines of the footings.

**752-4.2**  Concrete shall be measured by the number of cubic yards
(cubic meters) of concrete, complete in place and accepted.  In
computing the yardage of concrete for payment, the dimensions used shall
be those shown on the plans or ordered by the Engineer.  No measurements
or other allowances shall be made for forms, false work, cofferdams,
pumping, bracing, expansion joints, or finishing of the concrete.  No
deductions in yardage shall be made for the volumes of reinforcing steel
or embedded items.

**752-4.3**  The quantity of reinforcing steel to be paid for shall be
the calculated theoretical number of pounds (kilograms)placed as shown
on the plans, complete in place and accepted.  The unit weight used for
deformed bars shall be the weight of plain square or round bars, as the
case may be, of equal nominal size.

BASIS OF PAYMENT

**752-5.1**  Payment will be made at the contract unit price per cubic
yard (cubic meter) for unclassified excavation for structures; at the
contract unit price per cubic yard (cubic meter) for concrete for the
structures; and at the contract unit price per pound (kilogram) for
reinforcing steel.  These prices shall be full compensation for
furnishing all materials and for all preparation, excavation, and
placing the materials, and for all labor, equipment, tools, and
incidentals necessary to complete the structure.

Payment will be made under:

Item D‑752‑5.1 Unclassified Excavation for Structures---per cubic yard
(cubic meter)

Item D‑752‑5.2 Structural Concrete---per cubic yard (cubic meter)

Item D‑752‑5.3 Reinforcing Steel---per pound (kilogram)

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

**END OF ITEM D-752**

**Intentionally Left Blank**

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