703 Aggregate (002).pdf

703 Aggregate 703.01 Fine Aggregate for Concrete 1. Furnish sand conforming to AASHTO M 6, class B including the reactive aggregate supplementary requirement, except as amended or supplemented by the following: a. Material passing 75-μm sieve, AASHTO T 11 3.0% max. b. Sand equivalent value, AASHTO T 176, 75 min. 2. For lightweight fine aggregate, conform to AASHTO M 195.

703.02 Coarse Aggregate for Concrete 1. Conform to AASHTO M 80, class A, except as amended or supplemented by the following: a. Los Angeles abrasion, AASHTO T 96 60% max. b. Adherent coating, ASTM D 5711 1.0% max. c. Grading, AASHTO M 43 All sizes except numbers 8, 89, 9, or 10 2. For bridge decks or surface courses, do not use: (1) aggregates known to polish or carbonate; (2) aggregates containing less than 25 percent by mass of insoluble residue as determined by ASTM D 3042. 3. For lightweight coarse aggregate, conform to AASHTO M 195.

703.03 Granular Backfill 1. Furnish aggregate for the following installations. a. Underdrain pipe with geotextile. Furnish granular backfill conforming to AASHTO M 80, class E and AASHTO M 43, size number 3, 4, 5, 7, 57 or 67. b. Underdrain pipe without geotextile. Furnish granular backfill conforming to AASHTO M 6, except the soundness test is not required.

703.04 Permeable Backfill 1. Furnish either sand conforming to Subsection 703.15 or coarse aggregate consisting of sound, durable particles of gravel, slag or crushed stone conforming to Table 703-1.

703.05 Subbase, Base, and Surface Course Aggregate 1. General. Furnish hard, durable particles or fragments of crushed stone, crushed slag or crushed gravel conforming to the following: a. Los Angeles abrasion, AASHTO T 96 50% max. b. Sodium sulphate soundness loss (5 cycles), AASHTO T 104, 12% max. c. Durability index (coarse), AASHTO T 210 35 min. d. Durability index (fine), AASHTO T 210 35 min. e. Fractured faces, ASTM D 5821 50% min. f. California Bearing Ratio, ASTM D 1883 Minimum pavement design criteria g. Free from organic matter and lumps or balls of clay 2. Do not use material that breaks up when alternately wetted and dried. 3. Obtain the aggregate gradation by crushing, screening, and blending processes as necessary. Fine aggregate, material passing the 4.75mm sieve, shall consist of natural or crushed sand and fine mineral particles. 4. Subbase or base aggregate. In addition to 703.05.1 above, conform to the following: a. Gradation Table 703-2 b. Liquid limit, AASHTO T 89 25 max.

5. Surface course aggregate. In addition to 703.05.1 above, conform to the following: a. Gradation and plasticity index, AASHTO T 90 Table 703-3 b. Liquid limit, AASHTO T 89 35 max. 6. Do not furnish material that contains asbestos fibres.

703.06 Crushed Aggregate 1. Furnish hard, durable particles or fragments of crushed stone or gravel conforming to the size and quality requirements for crushed aggregate material normally used locally in the construction and maintenance of highways by T&T Ministry of Works and Transport. Furnish crushed aggregate with a maximum size of 25 mm as determined by AASHTO T 27 and T 11. Furnish crushed aggregate uniformly graded from coarse to fine and free of organic matter, lumps or balls of clay, and other deleterious matter.

703.07 Hot Asphalt Concrete Pavement Aggregate 1. Coarse aggregate (retained on a 4.75mm sieve). Furnish hard, durable particles or fragments of crushed stone, crushed slag, or crushed gravel conforming to the following: a. Los Angeles abrasion, AASHTO T 96 40% max. b. Sodium sulphate soundness loss (5 cycles), AASHTO T 104 12% max. c. Fractured faces, ASTM D 5821 75% min. d. Durability index (coarse), AASHTO T 210 35 min. 2. For the surface course, do not use: (1) aggregates known to polish or carbonate; (2) aggregates containing less than 25 percent by mass of insoluble residue when tested according to ASTM D 3042. 3. Fine aggregate (passing a 4.75mm sieve). Furnish natural sand, stone screenings, slag screenings or a combination thereof conforming to AASHTO M 29 including sulphate soundness and the following: a. Durability index (fine), AASHTO T 210 35 min. b. Sand equivalent value, AASHTO T 176, 45 min.

4. Composite aggregate blend. Size, grade, and combine the aggregate fractions in mix proportions conforming to the following: a. Gradation Table 703-4 b. Clay lumps and friable particles, AASHTO T 112 1.0% max. c. Reasonably free from organic or other deleterious material 5. Lightweight aggregate (slag). Furnish crushed slag conforming to the quality requirements of AASHTO M 195. Do not use any other kind or type of lightweight aggregate as defined in AASHTO M 195.