408.07 Application of Bituminous Material. Bituminous material shall be applied to the width of the section to be primed by means of a pressure distributor in a uniform, continuous spread. When traffic is maintained, not more than 2 of, the width of the section shall be treated in one application. Care shall be taken that the application of bituminous material at the junctions of spreads is not in excess of the specified amount. Excess bituminous material shall be squeegeed from the surface. Skipped areas or deficiencies shall be corrected. Building paper shall be placed over the end of the previous applications and the joining application shall start on the building paper. Building paper used shall be removed and satisfactorily disposed of. When traffic is maintained, one-way traffic shall be permitted on the untreated portion of the roadbed. As soon as the bituminous material has been absorbed by the surface and will not pick up, traffic shall be transferred to the treated portion and the remaining width of the section shall be primed. The quantities, rate of application, temperatures and areas to be treated shall be approved before application of the prime coat. The surfaces of structures and trees adjacent to the areas being treated shall be protected in such manner as to prevent their being spattered or marred. No bituminous material shall be discharged into a borrow pit, gutter, or stream. 408.08 Application of Blotter Material. If traffic must be routed over the primed surface before the bituminous material has penetrated sufficiently to prevent pickup by vehicles, or to minimize possible damage by rain before complete penetration, blotter material may be spread, as directed by the Engineer, to cover any unabsorbed bituminous material. Blotter material shall be spread so that no wheels or tracks will travel in uncovered wet bituminous material. Method of Measurement 408.09 Bituminous material will be measured by the ton or gallon and blotter material will be measured by the ton or cubic yard as provided in the bid schedule. When slag and stone (or gravel) are designated as alternative materials for pay items in the bid schedule and payment is by weight, the estimated quantities will be based on assumed average bulk specific gravities of available alternative materials. No adjustment in contract unit price will be made for variation in quantity due to differences in the specific gravity of the material actually used. Basis of Payment 408.10 The accepted quantities of prime coat, determined as pro vided above, will be paid for at the contract price per ton or gallon fo bituminous material and per ton or cubic yard for blotter materia complete in place, which price and payment will be full compensation for the work of this section. 409.01 This work shall consist of an application of bituminous material with or without an application of cover coat material in accordance with these specifications and in reasonably close conformity with the lines shown on the plans or established by the Engineer. The approximate amounts of materials per square yard for seal coats of the several types shall be as provided in table 409-1, adjusted to reflect variations in aggregate densities. The exact amounts to be used will be set by the Engineer. TABLE 409-1.-Quantities of materials for seal coats Materials 409.02 Bituminous Material. The type and grade of bituminous material will be specified in the contract. The bituminous material shall be of the type and grade called for in the bid schedule and shall conform to the following subsections: Application temperatures of bituminous materials shall conform to subsection 702.05. 409.03 Cover Coat Materials. Cover coat material shall meet the requirements of subsection 703.13 for the size shown in the bid schedule. The material may be accepted in stockpile at the source. Construction Requirements 409.04 Weather Limitations. Seal coat shall be applied only when the surface to be treated is dry or slightly damp, when the temperature of the road surface is 70° F (21 t° c) or more, and when the weather is not foggy or rainy. 409.05 Equipment. The following equipment or its equivalent shall be furnished: Equipment for heating and applying bituminous material shall meet the requirements of subsection 405.05. A rotary power broom and/or blower. When cover coat materials are applied: A minimum of one steel wheel roller and one pneumatic tire roller meeting the requirements of Section 212. A second pneumatic tire roller may be used in lieu of the steel wheel roller when approved. Steel wheel rollers shall be operated at a maximum speed of 3 miles per hour (1.34 m/s), and pneumatic tire rollers at a maximum speed of 5 miles per hour (2.24 m/s). One self-propelled aggregate spreader of approved design supported by at least 4 wheels equipped with pneumatic tires on two axles. The aggregate spreader shall be equipped with positive controls so that the required amount of material will be deposited uniformly over the full width of the bituminous material. Other types of aggregate spreaders may be used provided they accomplish equivalent results and are approved. 409.06 Preparation of Surface. Seal coating operations shall not be started until the surface is thoroughly compacted by rolling and traffic. Bituminous material shall not be spread until the surface has beer cleaned as required, and the section to be sealed has been approved. 409.07 Applying Bituminous Material. Bituminous materia shall be applied by means of a pressure distributor in a uniform continuous spread over the section to be treated and within the temperature range specified. The quantity of bituminous material to be used per square yard shall be as directed. If the texture of the surface is such that bituminous material penetrates too rapidly, a preliminary application of from 0.05 to 0.10 gallon per square yard (189 to 379 cm3 per 0.836 m2) of surface may be required. A strip of building paper, at least 3 feet (914 mm) in width and with a length equal to that of the spray bar of the distributor plus one foot (305 mm), shall be used at the beginning of each spread. If the cut-off is not positive, the use of paper may be required at the end of each spread. The paper shall be removed and disposed of in a satisfactory manner. The distributor shall be moving forward at proper application speed at the time the spray bar is opened. Any skipped areas or deficiencies shall be corrected. Junctions of spreads shall be carefully made to assure a smooth riding surface. The length of spread of bituminous material shall not be in excess of that which approved spreading equipment can immediately cover with approved material. The spread of bituminous material shall not be more than 6 inches (152 mm) wider than the width covered by the cover coat material from the spreading device. Under no circumstances shall operations proceed in such manner that bituminous material will be allowed to chill, set up, dry, or otherwise impair retention of the cover coat. The distributor, when not spreading, shall be parked so that the spray bar or mechanism will not drip bituminous materials on the surface of the traveled way. Type 1 seal coat shall be allowed to penetrate undisturbed for a period of not less than 24 hours. Any spots of excess bituminous material remaining at the end of that period shall then be lightly covered with sand or other approved local material and the surface opened to traffic. 409.08 Application of Cover Coat Material. Immediately following the application of the bituminous material, cover coat for types 2 and 3 seal shall be spread in quantities as designated. Spreading shall be accomplished in such a manner that the tires of the approved aggregate spreader at no time contact the uncovered and newly applied bituminous material. If directed, the cover coat material shall be moistened with water to eliminate or reduce the dust coating of the aggregate. Moistening shall be done the day before the use of the aggregate. In lieu of adding water the aggregate may be precoated with bituminous materials. Immediately after the cover coat material is spread, any deficient areas shall be covered by additional material. Initial rolling shall begin immediately behind the spreader and shall consist of one complete coverage with a power roller. Pneumatic tire rolling shall begin immediately after completion of the initial rolling and shall be continued until 3 complete coverages are obtained. Pneumatic tire rolling shall be completed the same day the bituminous material and cover coat materials are applied. After the application of the cover coat material, the surface shall be lightly broomed or otherwise maintained as directed for a period of 4 days or as directed. Maintenance of the surface shall include the distribution of cover coat material over the surface to absorb any free bituminous material and cover any area deficient in cover coat material. The maintenance shall be conducted so as not to displace imbedded material. Excess material shall be swept from the entire surface by means of rotary brooms. The surface shall be swept at the time determined by the Engineer. The Contractor shall furnish a pilot car and driver to conduct traffic over completed seal coat at a maximum speed of 25 miles per hour (40 km/hour) for the first 24 hours after cover aggregate is applied, if so directed by the Engineer. Method of Measurement 409.09 Bituminous material will be measured by the ton or gallon and cover coat material will be measured by the ton or cubic yard. When slag and stone (or gravel) are designated as alternative materials for pay items in the bid schedule and payment is by weight, the estimated quantities will be based on assumed average bulk specific gravities of available alternative materials. No adjustment in contract unit price will be made for variation in quantity due to differences in the specific gravity of the material actually used. Basis of Payment 409.10 The accepted quantities of seal coat determined as provided above, will be paid for at the contract price per ton or gallon for bituminous material and per ton or cubic yard for cover coat material complete in place, which price and payment will be full compensation for the work of this section. |