Coarse Aggregates. Coarse aggregates shall be angular particles of uniform density. The percentage of flat and/or elongated particles shall not exceed 20 in the fraction retained on the 12.5 mm (1/2 inch) sieve and in the fraction passing the 12.5 mm (1/2 inch) sieve. A flat particle is one having a ratio of width to thickness greater than 3; an elongated particle is one having a ratio of length to width greater than 3. When the coarse aggregate is supplied from more than one source, aggregate from each source shall meet the requirements set forth herein. Fine aggregate shall be natural sand or angular particles produced by crushing stone or gravel that meets the requirements for wear and soundness specified for coarse aggregate.
Coarse Aggregates. Standard Coarse aggregate for use in concrete (other than light weight concrete) shall conform to IS 383. Coarse aggregate shall have a minimum specific gravity of 2.6 (saturated surface dry basis). Aggregate below this specific gravity shall not be used without specific permission of the Engineer-In-Charge. Coarse aggregate shall consist of natural or crushed stone, angular in shape with granular or crystalline surfaces or approved river shingle or gravel, rounded in shape. All aggregate shall be clean and free from elongated, friable, flaky or laminated pieces, adherent coatings, clay lumps, mica, organic matter and any other deleterious matter that may cause corrosion of reinforcement or impair the strength and / or durability of concrete. It shall be chemically inert, hard, strong, dense, and durable against weathering. The maximum quantities of deleterious materials in the coarse aggregate shall not exceed the limits indicated in the IS 383 when tested as per IS 2386 Part-I & Part-II “Method of Tests for Aggregate for Concrete”.
Coarse Aggregates. The coarse aggregate, which may be either stone ballast or chips, should be well graded and preferably machine broken and should conform to IRS standard specifications and shall be obtained from approved quarries. The stone should be free from soft thin elongated or laminated or decayed pieces. The aggregate should before from dust. Cleaning and washing, if necessary, should be carried out as per directions of the site - Engineer or his representatives.
Coarse Aggregates. Coarse aggregates for all concrete work in all situations shall be graded crushed stone aggregate (crushed in mechanically operated crusher) of approved quality, irrespective of whether indicated specifically in the description of items or otherwise or SSR provisions. Nallah shingle will not be used even for plain cement concrete work in any situation. Contractor shall not be allowed to install crusher on Defence land.
Coarse Aggregates. The coarse aggregates used shall be clear, hard, washed and screened gravel or crushed stone having a specific gravity of not less than 2.56 and shall be free from dust, fine materials, clay or loam and soft, flat or elongated particles. The coarse aggregates used shall conform to the IS: 369 for grading, strength and all other properties. Where required by the consultants/ Vandavasi Municipality or its authorised representatives, the coarse aggregates shall be subject to the following tests in accordance with the procedure specified in IS: 383. • Sieve Analysis • Determination of clay, fine silt and fine dust in aggregates. • Organic impurities • Strength of test cubes • Soundness • Abrasion value
Coarse Aggregates a. Coarse aggregates shall be clean, hard, tough, water sound and free of deleterious substances.
