§ 11-126. Cement treated crushed stone base.

The cement treated crushed stone base shall meet the Arkansas State Highway Commission's Standard Specifications for Highway Construction, hereafter, referred to as the AHTD Standard Specification, requirements for cement treated crushed stone base course, with the following exceptions:

(1)

The cement treated crushed stone base shall consist of aggregate meeting the requirements for SB-2 or SB-3, three (3) percent to six (6) percent by weight of Type I Portland cement, and water at one (1) percent of optimum. The percent cement and water shall be determined from laboratory tests. The specimens of aggregate, cement and water must develop a compressive strength of at least 6y50 psi in seven (7) days. The type of asphalt used for protection and cover for the cement treated base will be at the option of the contractor, subject to the approval of the County Road Superintendent.

(2)

The cement treated base shall not be mixed or placed while atmospheric temperature is below thirty-five (35) degrees Fahrenheit within twenty-four (24) hours, or when the weather is foggy or rain. During cold weather the cement treated base shall be protected for seven (7) days. When the temperature is expected to drop below thirty-five (35) degrees Fahrenheit, a sufficient supply of hay, straw, or other material suitable for cover and protecting the previously placed material shall be used. Any cement treated base which has been damaged by freezing, or otherwise, shall be removed and replaced at the contractor's expense.

(3)

The crushed stone base, cement and water shall be mixed in a pugmill type central plant, a self-propelled or self-powered traveling mixer equipped with a rotor or other approved type mixer that will thoroughly mix the base and cement at the required depth and at or near the optimum moisture content, or by other methods approved by the County Road Superintendent.

(4)

The cement treated crushed stone base shall be placed on an approved subgrade and spread uniformly in such a manner that no segregation of coarse and fine particles will occur. Under no circumstances shall the base course be placed on a frozen subgrade.

(5)

The cement treated crushed stone base shall be constructed in layers not exceeding six (6) inches of compacted depth at substantially optimum moisture. The density of the cement treated crushed stone base, as determined by AASHTO T 191 or T 238, shall not be less than ninety-eight (98) percent of the maximum laboratory density obtained by the procedures described in section 11-111 for crushed stone base courses.

(6)

After the cement treated base has been finished, it shall be protected from drying by the application of approximately two-tenths (0.2) gallon per square yard of bituminous material. The bituminous material shall be applied as soon as possible, but in no case later than twenty-four (24) hours and maintained for seven (7) days.

(7)

No vehicles shall be allowed on the cement treated base during the seven-day curing period. Finished portions of cement treated base that are used by construction equipment shall be protected in such a manner to prevent equipment from marring or damaging the completed work. Any damage to the cement treated base resulting from vehicles shall be removed and replaced at the contractor's expense.

(8)

The depth of the cement treated base shall be within ½ inch of the depth shown in Table 2, Appendix A. The average of all depth measurements shall not be less than the required depth shown in Table 2, Appendix A, and any depth in excess of the + ½ inch shall not be used in computing the average depth.

(9)

When stringlined, the surface shall be within ½ inch of the typical section shown in Appendix B.

(Ord. No. 91-9, Art. 1, § 4.07, 4-11-91; Ord. No. 99-32, Art. 1, 7-8-99)