enough to avoid displacement of the mixture. Any displacement occuring as a result of reversing the direction of the roller, or from any other cause, shall be corrected at once by the use of rakes and of fresh mixture where required. Final rolling shall be done with powered rollers. Sufficient rollers of the designated types shall be furnished to adequately handle the output of the plant. Rolling shall proceed at an average rate not to exceed 350 square yards per hour per roller. Rolling shall continue until a density is obtained which is at least ninety-four (94) percent of the maximum density obtainable on the same mixture if compacted in a laboratory using the standard Proctor Method with all aggregate in the bituminous mixture passing the 2-inch sieve. (Reference A. A. S. H. O. Method T-99 with mixture at a temperature of 140° F. placed in three layers with twentyfive (25) blows per layer.) Field tests shall be made at least twice daily. To prevent adhesion of the mixture to the powered rollers, the wheels shall be kept properly moistened, but an excess of either water or oil will not be permitted. The rollers shall be kept in good condition and shall be operated continuously as far as practicable and in such a manner that all parts of the pavement shall receive substantially equal compression. At all places not accessible to the roller, the mixture shall be thoroughly compacted with hand tampers. Hand tampers shall weigh not less than twenty-five (25) pounds and shall have a tamping face area of not more than fifty (50) square inches. The surface of the mixture after compression shall be smooth and true to established crown and grade. Any mixture which becomes loose and broken, mixed with dirt, or in any way defective prior to the application of the tack coat or surfacing shall be removed and replaced with fresh mixture which shall be compacted to conform with the surrounding area, all to be done at the expense of the contractor. Skin patching on an area that has been rolled shall not be allowed. 215-4.8 JOINTS. (a) General. The mixture at the joints shall comply with the surface requirements and present the same uniformity of texture, density, smoothness, etc., as other sections of the course. In the formation of all joints, provision shall be made for proper bond with the previously placed material for the full specified depth of the course. Joints shall be formed by cutting back of the previous day's run so as to expose the full depth of the course, and the exposed edge shall be given a light paint coat of asphalt if necessary. The fresh mixture shall be raked against the joint, thoroughly tamped with tampers, and rolled. (b) Transverse. The placing of the course shall be as nearly continuous as possible. The roller shall pass over the unprotected end of the freshly laid mixture only when the laying of the course is to be discontinued. (c) Longitudinal. The placing of the course shall be in the manner as specified and so that the joint is exposed for the shortest period possible. The joint shall be placed so that it will not coincide with that in the subbase and will break joints by at least one (1) foot. 215-4.9 SHAPING EDGES. While the base is being compacted and finished, the contractor shall trim the edges neatly to line. 215-4.10 SURFACE TESTS. The finished surface shall not vary more than three-eighths (%) inch for the base course when tested with a sixteen (16) foot straightedge applied parallel with or at right angles to the centerline. Tests for conformity with the specified crown and grade shall be made by the contractor immediately after initial compression by powered rollers, and any variation shall be corrected by removing or adding materials and continuing the rolling. After the completion of final rolling, the smoothness of the course shall again be checked, and the humps or depressions exceeding the specified tolerances or that retain water on the surface shall be corrected by removing the defective work and replacing with new material or by adding additional material as directed by the engineer and at the expense of the contractor. 215-4.11 SAMPLING BASE. For the determination of composition, compaction, and density of the base the contractor shall remove suitable size samples of the completed base. Samples for each day or fraction thereof, when mixtures are placed, shall be taken by the engineer. The contractor shall replace the base where samples are removed, and these replacements shall be installed by the contractor free of charge. After the samples have been removed they will be tested by the engineer for density and composition. If the deficiency in composition and density exceeds the limits of toleration from that specified, satisfactory corrections shall be made. 215-4.12 MAINTENANCE. The surface shall be continually maintained until the base course is accepted. Following the construction of the course, the contractor shall do such rolling and other maintenance work as is necessary to maintain the surface density and grades and to keep the surface clean of any foreign material. The engineer shall have full and specified authority to stop all hauling over the completed or partially completed base course when such hauling is causing damage or is tracking excessive foreign material onto the course. 215-4.13 BITUMINOUS AND AGGREGATE MATERIAL CONTRACTOR'S RESPONSIBILITY. Samples of the bituminous and aggregate 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 material begins. The contractor shall require the manufacturer or producer of the bituminous and aggregate 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. For checking the adequacy of the equipment in use, inspecting the conditions and operation of the plant, for the verification of weights or proportions and character of materials and/or the determination and checking of temperatures being maintained in the preparation of the mixtures, the engineer or his authorized representatives shall have access at any time to all parts of the paving plant. The contractor shall furnish vendor's certified test report for each carload or equivalent of emulsified asphalt 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 materïal 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. 215-4.14 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 and paving 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, nor shall he release the car or tank until the final outage has been taken by the engineer. Copies of all freight bills and weigh bills shall be furnished to the engineer during the progress of the work. METHOD OF MEASUREMENT 215-5.1 The tonnage of emulsified asphalt aggregate base course to be paid for shall be the number of tons of the approved bituminous mixture called for in the bid schedule and used in the accepted work. The bituminous-treated material shall be weighed after mixing, and no deduction shall be made for the weight of bituminous material in the mixture or for the moisture within the limits of the specification. 215-5.2 The bituminous material and lime when used shall not be paid for separately but shall be included in the price bid for base course above, and shall be considered incidental to the price for this item. BASIS OF PAYMENT 215-6.1 The quantities of emulsified asphalt aggregate base mixture, determined as provided in 5.1 and 5.2 above, shall be paid for at the contract unit price per ton in the bid schedule for base course, which price and payment shall constitute full compensa-. tion for preparing the underlying course; for furnishing, handling, mixing, manipulating, and placing all materials; for all shaping, compacting, and rolling; for finishing; for improving unsatisfactory areas; for reconditioning the underlying course and shoulders; for furnishing samples; for furnishing and sealing of scales; for furnishing the weigh house; for all labor, equipment, tools, and incidentals necessary to complete the item, except any prime or tack coat. Payment will be made under: Item P-215-6.1 Emulsified Asphalt Aggregate Base Course— per ton. ITEM P-216 MIXED IN-PLACE BASE COURSE DESCRIPTION 216-1.1 This item shall consist of a base course composed of mineral aggregate and bituminous material, mixed in-place, constructed on the prepared underlying course in accordance with these specifications and in conformity with the dimensions and typical cross section shown on the plans, and with line and grade established by the engineer. 216–1.2 DETERMINATION OF PERCENTAGE OF BITUMINOUS MATERIAL. The percentage of bituminous material, by weight, to be added to the aggregate shall be between the limits as set forth in the table. The exact percentage to be used shall be fixed by the engineer on the basis of preliminary tests and field sieve analysis of the aggregate furnished. 216-1.3 JOB MIX FORMULA. No work shall be started on the project, nor any mixture accepted therefor, until the contractor has submitted samples of the materials intended for use and the engineer has established a satisfactory job mix formula based upon tests of the materials furnished. The formula shall be submitted in writing by the engineer to the contractor, indicating the definite percentage for each sieve fraction of aggregate and for bituminous cement. The material furnished shall conform to the approved job mix formula within the tolerances specified herein. JOB MIX TOLERANCES Aggregate passing sieve No. 4 and larger_-_- Bitumen.. Plus or Minus 7 percent. 5 percent. 2 percent. 0.5 percent. MATERIALS 216-2.1 AGGREGATE. The aggregate shall consist of crushed stone, crushed gravel, crushed slag, screenings, gravel, sandgravel, sand or other natural, granular, or approved material having essentially the same qualities and meeting all the requirements when combined within the limits for gradation. |