Panchayat:Repo18/vol2-page1422

2) Water absorption. Shall not be more than 15% by weight. 3) Crushing strength. Shall not be less than 3.5 Kg/cm, arrived at on an average of 6 brickstested. 4) Drop down test. Bricks dropped from 1.0m height shall be intact. 5) Frequency of testing. As and when source of supply changes. 2. Water 1) pH of water: shall not be less than 6. 2) Organic impurities: less than 2000 mg/litre. 3) Inorganic impurities: less than 3000 mg/litre. 4)Sulphites (SO3): less than 400 mg/litre. 5) Chlorides (CI): less than 500mg/litre for RCC works. 6) Chlorides (Cl): less than 2000mg/litre for other works. 7)Suspended matter: less than 2000mg/litre. Frequency testing: Once in 3 months or when the source changes. 3. Steel 1) Mean diameter: Checked on 3 samples of each size. 2) Weight per meter: Checked on 3 samples of each size on a 1.0m long piece. 3) Ductility (On bars below 20mm dia): 3 times bending should not cause break. 4) Tensile strength of Steelbars: To be ascertained at laboratory level on each size of bars Frequency of testing: On every fresh batch upon arrival. 4. Cement Manufacture's test certificate of every batch is mandatory. 5. Fine Aggregate Shall confirm to zone I as designated in IS383. Sieve Analysis to be carried out at site, Particle size distribution. 10 mm 100% passing 4.75 mm - 90 to 100% 2.36 mm - 60 to 95% 1.1 8 mm - 30 to 70% 600 miCrons - 15 to 34% 300 microns - O5 to 20% 150 microns - O to 10% 6. Coarse Aggregate Particle size distribution. 40 mm 100% passing 20mm 95 to 100% 4,75 mm - 3O to 50% 600 miCrOnS - 10 to 30% 150 microns - O to O6% Frequency of testing: When the source changes 7. Concrete Work 1) Mandatory test a) Slump test: 50/100mm for roofs, beams, slabs etc. tolerance is 25mm