CONCRETE: QUALITY CONTROLCONCRETE IS« No more three component s ystem. Is a multi-component and multi-variant system. Concrete includes- cement, coarse and fine aggregates, water , mineral and chemical admixtures, additives, performance improvers etc. As some materials are natural and o thers are processed, site conditions ±variation in quality is expected. Consistent quali ty with a minimum variation in the material is the target and to be maintained. TYPES OF CEMENTS: Ordinary Portland Cement(33 Grade) ±IS 269 Ordinary Portland Cement(43 Grade) ±IS 8112 Ordinary Portland Cement(53 Grade) ±IS 12269 Rapid Hardening Cement- IS 8041 Sulphate Resisting Cement-IS 12230 Portland Pozzolana Cement (part 1)-IS 1489 (fly-ash based) Portland Pozzolana Cement (part 11)-IS 1489 (calcined based) Portland Slag Cement-IS 455 Oil Well Cement- IS 8299 High Alumina Cement-IS 6452 etc Type of cement to be used for intended use. APPLICATIONS OF OPC: OPC 33 grade can be used in all genera l construction works where high strength is not requ ired. OPC 43 shall be used in pre-cast products, multistoried buildings, water tanks, canals etc. OPC 53 shall be used in structures where high strength is required ±elements of high rise buildings, railway sleepers etc . SULPHATE RESISTING CEMENT: If sulphates are more in soils/ water OPC is susceptible to attack. In such cases, a special t ype ofcement SRC to be used. SRC has sulphate resisting property. SRC is recommended to use in ±marine structures, foundations in aggressive soils, concrete pipes in marshy so ils etc IS:12230 PORTLAND POZZOLANA CEMENT (PPC): Portland Pozzolana Cement (Fly ash based) IS 1489 Part I Portland Pozzolana Cement ( Calcined clay based) IS 1489 Part II PPC is manufactured by the intergrinding of OPC clinker and pozzolanic material. The common pozzolanic material are- fly-ash, clay powder etc. WHAT IS POZZOLANA ? A pozzolanic material is essentially a siliceous/ siliceous aluminous material which does not possess cementations property, but, when finely gro und react with calcium hydroxide in the presence of water at ordinary temp. a nd forms compounds possessing cementations properties.
