301PLAIN CEMENT CONCRETE BASE COURSE

301.1DESCRIPTION—This work is construction of a normal or high early strength plain cement concrete

base course. When placed on subgrade, it includes the preparation of subgrade, as specified in Section 210.

301.2MATERIAL—

• Class A Cement Concrete—Section 704

• High Early Strength Cement Concrete—Section 704

• Supplementary Cementitious Material (SCM)*—Section 724.2

• Expansion Joint Filler—Section 705.1

• Longitudinal Construction Joint Material—Section 705.2

• Concrete Curing Material—Sections 711.1 and 2(b)

* SCM may be substituted for a portion of Portland cement.

301.3CONSTRUCTION—As specified in Section 501.3, except interpret references to "pavement" to

mean "base course," and for the following sections:

Forms are not required for base course widening 6 feet or less in width. However, use acceptable methods to contain the base course.

Where longitudinal joints are indicated or formed for convenience of construction, form a tied joint, as shown on the Standard Drawings for cement concrete pavement joints. In full width construction, sawing is not required.

Rake or broom finish the surface.

Liquid Membrane Forming Curing Compound, White, will not be allowed. Liquid Membrane Forming Curing Compound, Black, may be used, provided the cement

concrete base course is not accessible to traffic before the surface course is placed. Discontinue use of the compound if it becomes unsatisfactory as a curing agent; resume curing by other methods, as specified.

After the concrete has hardened, retest the surface of the base course, using straightedges. Operate the straightedge as specified in Section 501.3(k)3. Remove high points in excess of 1/4 inch by means of grinding or cutting tools, as directed. Remove and replace sections containing depressions of more than 3/8 inch, when directed in writing. Remove the full width of lane in which a depression occurs, for a length of at least 10 feet.

The Representative will determine when base course may be opened to traffic. However, do not open to traffic until the base course develops a required minimum compressive strength of 2,750 pounds per square inch as determined by compressive tests made on cylinder specimens in accordance with PTM No. 604 or as determined by maturity method in accordance with AASHTO T 413.

A traffic lane will be as indicated or as determined by the Representative.

Unless otherwise directed by the Representative in writing, remove and replace pavement defective in surface tolerance, as specified in Section 501.3(o); defective in depth, as specified in Section 501.3(s); defective in air content, as specified in Section 704.1(c)3.; or showing surface defects resulting from the effects of rain, improper final finish, or honeycombing which, in the Representative's opinion, cannot be repaired. The minimum pavement removal and replacement length is 10 feet, for the full width. When removing and replacing pavement defective in depth, start at the determined point of deficiency and proceed longitudinally until a section is reached where the deficiency is not more than 1/4 inch, and as specified. As directed, construct transverse joints needed because of the pavement removal.

301.4MEASUREMENT AND PAYMENT—Square Yard

Department will pay as follows:

Deficiency in Depth Determined by Cores Inches Proportional Part of Contract Price Allowed 0.0 to 0.25 0.26 to 0.30 0.31 to 0.35 0.36 to 0.40 0.41 to 0.45 0.46 to 0.50 100% 95% 90% 85% 80% 70%

The price includes the measuring apparatus, which remains the Contractor's property upon completion of the project. The Department will not pay for additional cores drilled if the depth is deficient by more than 1/4 inch.