Specifications include, but are not limited to: 1. Sand Sand shall consist of clean, hard, durable grains, free of lumps an organic material. All particles must pass a No. 8 sieve. 2. Crushed Rock Aggregate The aggregate shall consist of durable particles of crushed stone, free from frozen material or injurious amounts of salt, alkali, vegetable matter or other material either free or as adherent coating, and its quality shall be reasonably uniform throughout. It shall have a wear of not more than 40 percent when tested in accordance with TXDOT Test Method Tex-410-A. following requirements for percentage by weight: a. Fine Crushed Rock – Aggregate Grade 8 Retained on the ½ in sieve 0% Retained on the 3/8 in sieve 0 to 5% Retained on the No. 4 sieve 35 to 60% Retained on the No. 8 sieve 90 to 100% b. Standard Crushed Rock – Aggregate Grade 4 Retained on the 1½ in sieve 0% Retained on the 1 in sieve 0 to 5% Retained on the ½ in sieve 40 to 75% Retained on the No. 4 sieve 90 to 100% Retained on the No. 8 sieve 95 to 100% c. Course Crushed Rock Passing the 1½ in sieve 100% Retained on the ¾ in sieve 100% d. Rock for Foundation Passing the 5 in sieve 100% Retained on the 2 in sieve 100% e. Class “A” Embedment The embedment consists of a Type “B” concrete cradle and a cap of select material or granular material. Backfill a. Types “B” and “C” 1) General. Type “B” backfill is imported sandy gravel material. Type “C” backfill is native material from trench excavation. 2) Tests. The liquid limit shall not exceed 35 when tested in accordance with ASTM Designation D 423. The plasticity limit shall not exceed 12 when tested in accordance with ASTM Designation D 424. 3) Gradation. Percent of rock volume allowed is 50%. Percent of maximum allowable dimension of rock to total backfill volume is 3%. Greatest dimension of rock allowed in trenches 4 ft. or less in width is 3 in. and in trenches greater than 4 ft. in width, 6 in. Percent of backfill by volume, of clay lumps is 25%.Largest dimension of clay lumps is 6 in. for trenches 4 ft. or less in width and 10 in. for trenches greater than 4 ft. in width. 4) Flowable Backfill. Flowable backfill shall consist of a mixture of native soils or manufactured materials, cement and/or fly ash, and water which produces a material with unconfined compressive strength of between 250 and 450 psi after 28 days. Any material used shall be primarily granular, with a plasticity index <12 and with 100% passing a 3/4 in. sieve. The flowable mixture must be allowed to set prior to the placement of any overlying material.