3.1 DESCRIPTION AND GENERAL REQUIREMENTS: This item shall consist of furnishing all materials and performing all construction procedures required to build an asphalt pavement, on prepared and approved subgrade, conforming to the requirements of these specifications and to the pavement designs shown on the approved plans. It may include any, or all, but is not necessarily limited to, materials and methods specified under this Item (Item 3).
Asphalt pavement shall consist of an asphalt concrete surface course, or courses, constructed on a base course, or courses, and/or subbase course designed in compliance with the requirements of Item 4.4 of Attachment B of these regulations.
Successive layers of the pavement shall be offset from the edge of the underlying layer a distance equal to the course thickness of the lower layer except when abutting existing construction. When the asphalt layers of the pavement abuts a building foundation, barrier curb or similar vertical surface, the abutting surface shall be heavily painted with asphalt prior to construction of the asphalt course. The surface course shall be finished 1/4 inch above adjacent flush construction to permit proper compaction.
All catch basins, in pavement with granular base, shall be constructed with weep holes, at subbase level, to provide for drainage of seepage water from the granular layer. Weep holes shall be constructed of pipe, or other approved material, having an opening not less than 1.5 inches clear opening. Suitable provisions shall be made to prevent clogging of the opening. Three or more weep holes shall be suitably located around the perimeter of each catch basin.
3.2 MATERIALS AND CONSTRUCTION REQUIREMENTS
3.2.1 ASPHALT CONCRETE SURFACE COURSE: Asphalt concrete surface course materials and construction shall conform to the current requirements of the Kentucky Department of Highways for Asphalt Concrete Surface, Class I.
Surface course mixture composition may conform to the requirements of either surface course I or II as set forth in Table 5. Minimum asphalt concrete surface course thickness shall be as stated in Table 6 of these regulations.
3.2.2 ASPHALT CONCRETE BASE COURSE: Asphalt concrete base course materials and construction shall conform to the current requirements of the Kentucky Department of Highways, Specifications for Asphalt Concrete Base Course, Class I, except as noted herein.
Composition requirements of the mixture shall conform to the gradation limits for asphalt concrete base Course I or II set forth in Table 5. Asphalt content used shall fall within the range shown and shall be approved by the Planning Commission, or its duly authorized representative.
Uncrushed gravel and natural sand may be used as aggregate provided all other requirements of the specification are complied with.
3.2.3 ASPHALT TREATED BASE COURSE: Asphalt treated base course materials and construction procedures shall conform to the following requirements:
Aggregates may be crushed or uncrushed material conforming to the gradation requirements, shown in Table 5 for either base III or base IV.
The aggregate shall be composed of hard durable particles and shall contain no more than a total of 5% deleterious substances. The sand equivalent of the aggregate shall not be less than 25 when tested in accordance with AASHO Designation: T-176-56. The liquid limit of that portion of the aggregate finer than a No. 40 sieve shall not exceed 25 nor the plasticity index exceed six when tested in accordance with AASHO Designations: T-89 and T-91 respectively.
Asphalt cement shall conform to cement requirements of the Kentucky Department of Highways for penetration grades 60-70 or 85-100. Asphalt content shall be within the limits shown in Table 5.
The contractor shall set a single gradation and asphalt content, within the specified limits, as the Job Mix Formula to be used on the project. This formula must be approved by the Planning Commission, or its duly authorized representative, prior to use. Gradation and asphalt content may vary during construction within the following tolerances:
% Passing 3/4" or 3/8" Sieve- | " 10% |
% Passing No. 8 Sieve- | " 8% |
% Passing No. 50 Sieve- | " 6% |
% Passing No. 100 Sieve- | " 3% |
% Asphalt - | " .4% |
Other construction requirements shall conform to those specified by the Kentucky Department of Highways for Asphalt Concrete except that a gradation unit on the plant shall not be required provided the aggregate can be controlled by other means to produce a consistently uniform gradation.
3.2.4 CRUSHED AGGREGATE BASE COURSE
3.2.4.1 DESCRIPTION: Crushed aggregate base course, when provided for in the approved structural design of the pavement, shall consist of a granular layer constructed on prepared subgrade or subbase in accordance with these specifications and in conformity with the approved dimensions, lines, grades, and cross sections.
3.2.4.2 MATERIALS AND CONSTRUCTION METHODS: Crushed aggregate base course shall conform to all the current requirements for materials and construction methods of the Kentucky Department of Highways for dense graded aggregate base course except that 100% crushed gravel (at least one major crushed face on all aggregate coarser than a No. 4 sieve) may be used. When use of a crushed gravel is elected, aggregate shall conform to all other requirements of the referenced specification. In addition, fine aggregate (finer than a No. 4 sieve shall consist of angular particles produced from crushing larger gravel particles. If necessary, fine aggregate produced from crushed stone may be blended, by approved mechanical methods, at the mixing plant to produce the required gradation.
3.2.5 GRANULAR SUBBASE COURSE
3.2.5.1 DESCRIPTION: Subbase, when provided for in the approved structural design of the pavement, shall consist of a granular layer conforming to the following material and construction specifications.
3.2.5.2 AGGREGATE REQUIREMENTS: Material for granular subbase may be crushed or uncrushed aggregate containing no more than a total of 5% deleterious substances, such as, but not limited to, shale, soft particles, coal, or lignite. The subbase aggregate shall have a sand equivalent, as determined from AASHO Designation T-176, of not less than 25. That portion of the aggregate passing a No. 40 sieve shall have a liquid limit of not more than 25 and a plasticity index of not more than six when tested in accordance with AASHO Designations T-89 and T-91, respectively. Gradation of granular subbase shall be reasonably uniform and consistent and shall conform to the gradation requirements set forth in Table 5 for asphalt treated base III or IV.
3.2.5.3 CONSTRUCTION OF SUBBASE: Subbase shall be constructed on completed and approved subgrade to the required dimensions, grade, and cross section. Aggregate shall be spread by mechanical spreaders, or other equipment approved by the Planning Commission, or its duly authorized representative, capable of spreading material uniformly in layers not exceeding six inches compacted depth. Subbase shall be compacted with approved equipment to not less than 100% AASHO Designation T-99 density.
3.2.6 ASPHALT PRIME COAT: Asphalt prime coat shall be applied to the surface of granular courses upon which asphalt base or surface courses will be constructed.
Asphalt prime shall conform to the Kentucky Department of Highways requirements for cutback asphalt emulsion primer type L. Prime shall be applied to the surface of granular base course at a rate of 0.20 to 0.40 gallons per square yard, as directed by the Planning Commission, or its duly authorized representative, in conformance with requirements of the referred to specification.
3.2.7 ASPHALT TACK COAT: Tack coat shall consist of SS-lh, meeting the current requirements of the Kentucky Department of Highways. It shall, when directed by the Planning Commission, or its duly authorized representative, be diluted with equal parts of water. Application equipment and procedure shall conform to the requirements of the Kentucky Department of Highways for Tack coats. Tack Coat shall be applied to the surface of asphalt courses that have become dusty or dry from traffic use before the subsequent course is constructed or in other circumstances when the Planning Commission, or its duly authorized representative, so directs.
(Ord. 1971-2, passed 4-6-71)