3−1PART 300 AGGREGATE AND GRAVEL BASE AND SUBBASE COURSES
301.01 DESCRIPTION. This work consists of providi ng one or more courses of graded aggregate
or gravel borrow and fillers, if required, on prepared subgrade surfaces in reasonable close conformity with the dimensions and details indicated on the Plans, all in accordance with these Specifications.
301.02 MATERIALS. The following materials shall conform to the applicable requirements of the
indicated Subsections of SECTION M; MATERIALS:
a.Gravel Borrow; Subsection M.01.09, Table I, Column I. b. Crushed Stone or Gravel; Subsection M.01.09, Table I, Column II. c. Fillers; Subsection M.01.08, Fine Aggregate. All materials shall conform to all applicable specification requirements prior to final placement on the project. The practice of culling deleterious or out of specification material after placement and/or grading in-place will not be allowed.
301.03 CONSTRUCTION METHODS. 301.03.1 Placing. If the required compacted depth of the base course exceeds 12 inches, the
base shall be constructed in two or more layers of approximate equal thickness. The maximum compacted thickness of any one layer shall not exceed 12 inches. The maximum size of stone in the gravel borrow or aggregate placed, shall not exceed 3/4ths of the depth of the layer after compaction. This restriction determines the maximum size of stone in the gravel borrow specification of Subsection M.01.09; Gradation of Aggregate .
301.03.2 Shaping and Compaction. Compaction of each layer shall continue until a density of
not less than 95 percent of the maximum densit y determined in accordance with AASHTO T180 has been achieved. The surface of each layer shall be maintained during the co mpaction operations in such a manner that a reasonable uniformity is produced. The compacted surface shall have a tolerance of ½-inch, plus-or-minus, to the grades shown on the Plans or as directed. However, no plus or minus deviation may continue for more than 100 feet in any direction. Field moisture content for Gravel Borrow shall be adjusted, if necessary, to be no greater than two percent (+2%) above the optimum moisture content.
301.04 METHOD OF MEASUREMENT. "Aggregate Base Course" and/or "Gravel Borrow Base
Course" will be measured by the number of cubic yard s or the number of tons, as the case may be,
Source: Rhode Island Standard Specifications (Bluebook), 2024 Edition. Pages 173–173 of 826.