305 Portland Cement Concrete Base


Method of Measurement

Basis of Payment

Documentation Requirements 305 Portland Cement Concrete Base



When constructing this item, the requirements of 451 apply with the following exceptions:

1.        Reinforcing mesh required by 451.07 is not required in concrete base.

2.        The curing application rate for the membrane forming curing compound for concrete base is 200 square feet per gallon (5 square meters per liter) instead of what is specified for 451 and 452 pavement described in 451.10.

3.        Provide dowels at transverse contraction joints in mainline pavement, ramps, acceleration/deceleration lanes, or collector/distributor lanes. Dowels are not required in shoulders for mainline pavement, ramps, acceleration/deceleration lanes, or collector/distributor lanes unless the transverse contraction joint is located within 500 feet of a pressure relief joint.

4.        Construction joints are NOT to be placed within 6 feet of another parallel joint.

5.        The surface finish for concrete base is broom dragged in either the longitudinal or the transverse direction to provide a uniform, gritty surface texture to the satisfaction of the Engineer. Transverse grooving per 451.09 is not required.

6.        Surface smoothness variations for concrete base are not to exceed 1/4 inch in 10 feet (6 mm in 3 m).

7.        Station numbers as required in 451.09 are not required for concrete base.


Method of Measurement

The concrete base must be field measured and the area of pavement placed calculated for payment in square yards (square meters). The area is determined the same as for 451 or 452 pavement.

The pavement width for payment will be based on the plan typical cross-section plus any additional widening that has been directed by the Engineer. The length will be field measured along the centerline of the roadway or ramp.


Basis of Payment

Pay a reduced price for base found deficient in thickness according to 451.17. There is no additional payment for a concrete base thicker than that shown in the plans. Pay for accepted quantities at the contract price per square yard (square meter).


Documentation Requirements - 305 Portland Cement Concrete Base

1.        Document thickness checks of forms (where applicable) and of the plastic concrete during placement.

2.        Document condition of base material prior to placement.

3.        Document type, alignment, grade, and condition of forms.

4.        Document placement of transverse contraction joints including dowel basket anchoring, dowel alignment and depth, joint spacing, oiling of dowels, removal of assembly wires.

5.        Document placement of tiebars or hook bolts for longitudinal joints.

6.        Document weather conditions; beginning and ending temperatures, rain, wind, etc.

7.        Document type of equipment used.

8.        Document results of required concrete tests.

9.        Document any issues or observations during placement operations.

10.     Document surface tolerance checks.

11.     Document curing type and quantity required and used.

12.     Measure and document width and length for payment.

13.     Provide documentation on CA-D-3A, CA-D-3B, or other approved form(s).