309.03 Proportioning. Proportions for concrete mix will be based on a predetermined cement content of 6 sacks per cubic yard, in accordance with subsection 501.03 (a). 309.04 Equipment. The equipment shall meet the requirements of subsection 501.04. 309.05 Construction Requirements. The construction methods used shall meet the applicable requirements of subsections 501.05 through 501.14 inclusive, subsections 501.15(a) through 501.15(d) inclusive, and subsections 501.17 through 501.22 inclusive. 309.06 Surface Finishing. The surface of the concrete shall be broomed and slightly roughened. The surface shall be finished so that there will be no deviation of more than 1/4 inch between any two contact points when tested with a 10-foot straight edge placed parallel to the center line. 309.07 Tolerance in Base Thickness. The procedures for concrete base thickness determination will be in accordance with subsection 501.23. Method of Measurement 309.08 Portland cement concrete base will be measured by the square yard complete in place. The width for measurement will be the width of the pavement shown on the plans and additional widening where called for, or as otherwise directed and measured horizontally. The length will be measured horizontally along the centerline of each roadway or ramp. 309.09 Basis of Payment (a) General. The accepted quantities of Portland Cement Concrete Base, determined as provided above, will be paid for at the contract unit price per square yard for portland cement concrete base, which payment will be full compensa tion for furnishing and placing all materials, including any reinforcing except as provided in subsection 309.09 (cc), dowels and joint material; provided, however, for any base found deficient in thickness by more than 0.2 inch, but not more than 1:0 inch, only the reduced price stipulated below will be paid. No additional payment over the unit contract bid price will be made for any base which has an average thickness in excess of that shown on the plans. Payment will be made under: (b) Price adjustment.-Price adjustments for concrete base found to be deficient in thickness will be made in accordance with subsection 501.25(b). (c) Reinforcement.-Payment for a bottom layer or reinforcement, if called for in approach slabs at structures, will not be considered included in the foregoing price and payments but the weight of such reinforcement will be included in the weight to be paid for under section 602. Sections 310 through 399.-RESERVED Section 400 BITUMINOUS PAVEMENTS Section 401.-PLANT MIX BITUMINOUS 401.01 Description These specifications include general requirements that are applicable to all types of bituminous pavements of the plant mix type irrespective of gradation of aggregate, kind and amount of bituminous material, or pavement use. Deviations from these general requirements will be indicated in the specific requirements for each type. This work shall consist of one or more courses of bituminous mixture constructed on the prepared foundation in accordance with these specifications and the specific requirements of the type under contract, and in reasonably close conformity with the lines, grades, thicknesses, and typical cross sections shown on the plans or established by the Engineer. Materials 401.02 Composition of Mixtures. The bituminous plant mix shall be composed of a mixture of aggregate, filler and hydrated lime if required, and bituminous material. The several aggregate fractions shall be sized, uniformly graded and combined in such proportions that the resulting mixture meets the grading requirements of the job-mix formula. Before stockpiling aggregate the Contractor shall submit a proposed job-mix formula in writing, for use by the Engineer in setting the job-mix to be used with the proposed materials. The formula submitted shall propose definite single values for: (a) The percentage of aggregate passing each specified sieve. (b) The percentage of bituminous material to be added, on the total aggregate basis. (c) The temperature of the mixture leaving the mixer. (d) The temperature of the mixture delivered on the road. (e) The grade of bituminous material. Values shall be proposed within the limits specified for the particular type of bituminous concrete called for. The Engineer will determine a job-mix formula with single values for (a), (b), (c), (d), and (e) above and so notify the Contractor in writing. The mixture furnished by the Contractor shall conform to this job-mix formula, within the following range of tolerances: Aggregate passing the No. 4, and larger Aggregate passing the No. 8 through No. 100 sieves Aggregate passing the No. 200 sieve +4 percent. +7 percent. ±2 percent. ±0.4 percent. Bituminous material Temperature leaving the mixer Temperature delivered on the road +20° F. +20° F. The mixture shall also have an index of retained strength of not less than 70 when tested by AASHO T 165. For aggregates having maximum sizes over 1 inch, T 165 will be modified to use 6 inch by 6 inch cylindrical specimens. The 6 inch cylinders will be compacted by the procedures outlined in AASHO T 167 modified to employ 10 repetitions of a molding load of 1,400 pounds per square inch, with no appreciable holding time after each application of the full load. When unsatisfactory results make it necessary, the Engineer may establish a new job-mix formula and so notify the Contractor in writing. Should a change in sources of material be proposed, a new job-mix formula will be established before the new material is used. The plant mixed material will be accepted after blending or mixing at the plant or prior to final incorporation in the work. 401.03 Aggregates. Aggregates shall meet the applicable requirements of Section 703-Aggregates. The aggregate will be sampled for test from the stockpile or from the bins at the plant. 401.04 Filler. Filler shall meet the requirements of subsection 703.15. 401.05 Hydrated Lime. Hydrated lime shall meet the requirements of subsection 712.03. 401.06 Bituminous Materials. The type and grade of bituminous material will be specified in the contract. The grade may be changed one step by the Engineer at no change in unit price. Asphalt cement shall conform to subsection 702.01, for the grade specified. Tar shall conform to subsection 702.02 for the grade specified. Bituminous material may be conditionally accepted at the source, subject to the provisions of clause 10 of the General Provisions. Samples will be taken from the storage tanks specified in subsection 401.08(a) (2). Construction Requirements 401.07 Weather Limitations. Bituminous plant-mix shall be placed on a dry, unfrozen surface when the atmospheric temperature in the shade is above 40° F. and rising or above 50° F. if falling. Bituminous plant mix shall not be placed when weather conditions prevent the proper handling or finishing of the bituminous mixtures. 401.08 Bituminous Mixing Plant. Sufficient storage space shall be provided for each size of aggregate. The different aggregate sizes shall be kept separated until they have been delivered to the cold aggregate feeding system. The storage yard shall be maintained neat and orderly and the separate bins shall be readily accessible for sampling. Plants used for the preparation of bituminous mixtures shall conform to all requirements under (a) except that scale requirements shall apply only where weight proportioning is used. In addition, batch mixing plants shall conform to the requirements under (b); and continuous mixing plants shall conform to the requirements under (c). (a) Requirements for all plants.-Mixing plants shall be of sufficient capacity and co-ordinated to adequately handle the proposed bituminous construction. (1) Plant scales.-Scales shall be accurate to 0.5 per cent of any load that may be required and sensitive to one half the minimum graduation, which shall not be greater than 10 lbs. Poises shall be designed to be locked in any position to prevent unauthorized change of position. In lieu of plant and truck scales, the Contractor may provide an approved automatic printer system which will print the weights of the material delivered, provided the system is used in conjunction with an approved automatic batching and mixing control system. Such weights shall be evidenced by a weigh ticket for each load. Scales shall be inspected and sealed in accordance with subsection 106.05. (2) Equipment for preparation of bituminous material.— Tanks for the storage of bituminous material shall be equipped to heat and hold the material at the required temperatures. The heating shall be accomplished by steam coils, electricity, or other approved means so that no flame shall |