mats may be either one-fourth (4) of an inch, three-eighths (%) of an inch, or one-half (2) of an inch diameter; and transverse bars may be either one-fourth (4) of an inch or three-eighths (%) of an inch diameter. Longitudinal members in welded wire fabric shall be spaced not less than four (4) inches nor more than six (6) inches center to center; and, in bar mats, not less than six (6) inches nor more than twelve (12) inches center to center. Transverse members in welded wire fabric shall be spaced not less than six (6) inches nor more than twelve (12) inches center to center; and in bar mats, not less than six (6) inches nor more than eighteen (18) inches center to center. Ends and sides of adjacent sheets or mats shall be overlapped to provide continuous reinforcing throughout each slab panel. The center of end laps of sheets or mats (transverse laps) shall be located at least two (2) feet from transverse dummy joints; and the center of side laps (longitudinal laps) at least two (2) feet from longitudinal dummy joints. Longitudinal and transverse members of bar mats shall be lapped at least forty (40) bar diameters. Longitudinal members of wire fabric sheets shall be lapped at least forty (40) wire diameters but not less than twelve (12) inches; and transverse members shall be lapped at least six (6) inches as measured between centers of the outside longitudinal wires of overlapping sheets. 501-3.26 PLACING REINFORCEMENT. The concrete shall be struck off by means of a mechanical templet, to the proper depth below the specified finished surface, before reinforcement is placed. The reinforcing steel and the top layer of concrete shall be placed within thirty (30) minutes after the concrete is struck off. The reinforcing steel shall be placed two (2) inches below and parallel to the finished surface of the pavement, unless otherwise shown on the plans. The steel shall not extend across the expansion or contraction joints, but shall be discontinued two (2) inches back from the joints. The reinforcing sheets and mats shall be laid with the main members of the long axis of the opening parallel with the centerline of the pavement. Adjacent sheets of the reinforcing steel shall be lapped not less than twelve (12) inches when the lap is made perpendicular to the centerline of the pavement and not less than six (6) inches when made parallel to the centerline of the pavement. The sheets forming each lap shall be securely wired or clipped together at the edges of the sheets, with similar fastenings spaced evenly between, at distances not to exceed forty-two (42) inches. 501-3.27 OPENING TO TRAFFIC. The pavement shall be closed to traffic, including the vehicles of the contractor, for a period of ten (10) days after the concrete is placed, or longer if, in the opinion of the engineer, the weather conditions make it necessary to extend this time. The contractor shall furnish, place, and maintain satisfactory barricades and lights, as directed, to exclude all traffic from the pavement. Any damage resulting to the pavement due to traffic shall be repaired or replaced at the expense of the contractor. 763591°-48- -21 Power shovels, cranes, paving mixers, and similar heavy equipment shall not be moved or operated on the pavement without the written approval of the engineer. The pavement shall not be opened to traffic until all joints have been filled and sealed. METHOD OF MEASUREMENT 501-4.1 The yardage to be paid for shall be the number of square yards of either plain or reinforced pavement as specified, in place, completed and accepted, less deductions as hereinabove required for deficient thickness. BASIS OF PAYMENT 501-5.1 The yardage measured, as provided above, shall be paid for at the contract unit price per square yard bid for plain or reinforced Portland cement concrete pavement, which price and payment shall constitute full compensation for furnishing and preparation of all materials, including such transverse and longitudinal joints, reinforcing steel, joint filler, dowels or load-transfer devices, as are required in the plans; for placing, finishing, and curing; for all labor, equipment, tools, and incidentals necessary to complete the item; provided, however, that said unit price shall be reduced when and as required hereinabove for deficient thickness. Payment will be made under: Item P-501-5.1 Portland Cement Concrete Pavement-per MISCELLANEOUS ITEM P-602 BITUMINOUS PRIME COAT DESCRIPTION 602-1.1 This item shall consist of an application of bituminous material on the prepared base course in accordance with this specification and at the rate of application ordered by the engineer. The type of bituminous material to be used will be selected by the engineer from those included in this specification. 602-1.2 QUANTITIES OF BITUMINOUS MATERIAL. The approximate amount of bituminous material per square yard for the prime coat shall be as provided in the table. The exact amount to be used shall be determined by the engineer. 602-2.1 MATERIALS. The bituminous material to be used for the prime coat shall conform to the kind, grade, and specifications as follows: Refined tar, grade RT-2, RT-3-conforming to the requirements of A. A. S. H. O. Specification M-52. Medium curing cut-back asphalt, MC-0, MC-1-conforming to the requirements of A. A. S. H. O. Specification M-82. CONSTRUCTION METHODS 602-3.1 WEATHER LIMITATIONS. The prime coat shall be applied only when the existing surface is dry or contains sufficient moisture to get uniform distribution of the bituminous material when the atmospheric temperature is above 60° F., and when the weather is not foggy or rainy. The temperature requirements may be waived, but only when so directed by the engineer. 602-3.2 EQUIPMENT. The equipment used by the contractor shall include a self-powered pressure bituminous material distributor, and equipment for heating bituminous material. The distributor shall have pneumatic tires of such width and number that the load produced on the base surface shall not exceed 650 pounds per inch of tire width and shall be so designed, equipped, maintained, and operated that bituminous material at even heat may be applied uniformly on variable widths of surface at readily determined and controlled rates of from 0.05 to 2.0 gallons per square yard, with a pressure range of from 25 to 75 pounds per square inch, and with an allowable variation from any specified rate not to exceed five (5) percent. Distributor equipment shall include a tachometer, pressure gauges, volume-measuring devices, and a thermometer for reading temperatures of tank contents. Equipment for heating bituminous material shall consist of a tank with steam coils so designed that steam will not be introduced into the material. Other approved equivalent heating facilities may be used. 602-3.3 APPLICATION OF BITUMINOUS MATERIAL. Immediately before applying the prime coat, if the surface is sufficiently bonded, the full width of the surface to be primed shall be swept with a power broom equipped with blower. In any case care shall be taken to remove all loose dirt and clay or other loose and objectionable material. After the operation of removing the dust has been completed, and prior to the application of the prime coat, an inspection shall be made of the base to determine its fitness to receive the bituminous priming material. That portion of the base proposed for immediate treatment, if very dry, shall be lightly sprinkled immediately in advance of the application, as directed. The application of the bituminous priming material shall be by means of a pressure distributor of approved type, and shall be made at the pressure and in the amounts as directed by the engineer. The temperature of application shall be between 80° F. and 150° F. for tar; for MC-0 cut-back, the temperature range shall be between 50° F. and 125° F.; and for MC-1 cut-back, between 100° F. and 175° F. Following the application, the primed surface shall be allowed to dry for a period of not less than forty-eight (48) hours without being disturbed, or for such additional period of time as may be necessary to permit the drying out of the prime until it will not be picked up by traffic or equipment, which period shall be determined by the engineer. The surface shall then be maintained by the contractor until the surfacing has been placed. Suitable precautions shall be taken by the contractor to protect the prime surface against damage during this interval, including supplying and spreading any sand necessary to blot up excess bituminous material. 602-3.4 BITUMINOUS MATERIAL CONTRACTOR'S RESPONSIBILITY. Samples of the bituminous materials that the contractor proposes to use, together with a statement as to their source and character, must be submitted and approval obtained before use of such materials begins. The contractor shall require the manufacturer or producer of the bituminous materials to furnish material subject to this and all other pertinent requirements of the contract. Only those materials that have been demonstrated by service tests as satisfactory for the intended use will be acceptable. The contractor shall furnish vendor's certified test report for each carload, or equivalent, of bituminous material shipped to the project. The report shall be delivered to the engineer before permission is granted for use of the material. The furnishing of the vendor's certified test report for the bituminous material shall not be interpreted as a basis for final acceptance. All such test reports shall be subject to verification by testing of samples of materials as received for use on the project. 602-3.5 FREIGHT AND WEIGH BILLS. Before the final estimate is allowed the contractor shall file with the engineer receipted bills where railroad shipments are made, and certified weigh bills when materials are received in any other manner, of the bituminous materials actually used in the construction covered by the contract. The contractor shall not remove bituminous material from the tank car or storage tank until the initial outage and temperature measurements have been taken by the engineer, nor shall the car or tank be released until the final outage has been taken by the engineer. Copies of freight bills and weigh bills shall be furnished to the engineer during the progress of the work. METHOD OF MEASUREMENT 602-4.1 The gallonage of bituminous prime coat to be paid for shall be the number of gallons of the material used as ordered for the accepted work, corrected to gallons at 60° F., in accordance with A. S. T. M. Designation D-206, for asphalt materials, and in accordance with an appropriate table for tars; provided, however, that the measurement shall be in tons (2,000 pounds) in cases where the bid schedule calls for tons of bituminous material. 602-5.1 BASIS OF PAYMENT The gallonage or tonnage, determined as provided above, shall be paid for at the respective contract unit price per gallon or ton in the bid schedule for bituminous prime coat, which price and payment shall be full compensation for furnishing, delivering, and applying the material; for cleaning surface; for furnishing and spreading blotter material; for all labor, equipment, and tools, and incidentals necessary to complete the item. Payment will be made under: Item P-602-5.1 Bituminous Prime Coat-per gallon or per ton. |