**Material Specification 513---Precast Concrete Piles**

**1. Scope**

This specification covers the quality of precast concrete piles.

**2. General requirements**

The piles shall conform to the details shown on the drawings. The piles
shall be cast of portland cement concrete mixed, placed, and cured by
the methods specified in Construction Specification 31 except as amended
in the specification. The finished piles shall be true to line with a
smooth surface free from stone pockets, honeycomb, or other surface
defects.

**3. Classes of concrete**

Unless otherwise specified, Class 4000 concrete applies.

**4. Reinforcement**

Reinforcement steel shall conform to the requirements of Construction
Specification 34*.*

**5. Forms**

Forms shall be constructed of plywood, metal, or dressed lumber and
shall have 1-inch chamfer strips at all corners. They shall be mortar
tight, true to line, and adequately supported to prevent deformation or
settlement during concrete placement. They shall be designed to be
removable without damaging the completed piles.

**6. Placing concrete**

The concrete shall be placed in each pile in one continuous operation.
The concrete shall be compacted and worked into the forms and around the
reinforcement by procedures outlined in Construction Specification 31.

**7. Curing**

The piles shall be cured for a minimum of 14 days by a method specified
in Construction Specification 31.

Test cylinders cast for the purpose of determining when the piles may be
subjected to handling stresses shall be cured by the same method as the
pile, at the same location, and under the same conditions as those
applied to the piles.

The steam curing process may be used as an alternative to moist curing
or membrane curing. The piles shall be cured inplace on the casting bed
by the introduction of steam into a steam-tight housing that completely
encloses the casting bed. The first application of steam shall be
applied after the concrete has gained an initial set, but in no case
sooner than 2 hours after the concrete is placed unless a set-retarding
admixture is an ingredient of the approved concrete mix. When a
set-retarding admixture is used, the first application of steam shall be
applied no sooner than 4 hours after the concrete is placed. Moist
curing methods shall be applied during the interval between the
placement of the concrete and the application of the steam.

The steam shall be at 100 percent relative humidity and shall not be
applied directly on the concrete. During application of the steam, the
ambient air temperature within the housing shall be increased at a
maximum rate of 40 degrees Fahrenheit per hour until the maximum
temperature is reached. The temperature within the housing shall be
maintained between 140 and 160 degrees Fahrenheit until the concrete has
reached the specified strength. In discontinuing the application of the
steam, the ambient air temperature within the housing shall be decreased
at a maximum rate of 40 degrees Fahrenheit per hour until the
temperature within the housing does not exceed than 20 degrees
Fahrenheit above the ambient air temperature outside the housing.

The concrete shall not be exposed to temperatures below freezing for a
minimum of 6 days after placement.

**8. Removing forms**

Side forms shall remain in place a minimum 24 hours.

**9. Handling and storing piles**

The contractor shall handle and store piles by methods that do not cause
spalling, cracking, or other damage to the piles. The contractor shall
furnish all bridles, slings, and other handling equipment as necessary.

Piles shall not be moved until the tests indicate a minimum compressive
strength of 80 percent of the design 28-day compressive strength. Piles
shall not be transported or driven until the field cure test cylinders
indicate a minimum compressive strength equal to the design 28-day
compressive strength.

Piles that are cracked, spalled, or otherwise damaged during handling
will be rejected.