Developers

5.2.4 Sand - The fine aggregate or sand may be natural or crushed. Itmay be available in a quarry. Thesize of sand particles varies from amaximum of 4.75 mm down to 150micron, that is, 0.150 mm. Goodsand must contain all the particleswithin the above range, that is, itshould be graded sand. The sandmay be sieved through the followingIndian Standard Sieves: 4.75 mm,2.36 mm, 1.18 mm, 600 micron, 300micron and 150 micron. The sandmay be classified as VERY COARSE(ZONE I), MEDIUM COARSE (ZONEII), COARSE (ZONE III) and FINE (ZONE IV) depending upon its grainsize distribution.Sand must be clean and free from clay, alkali and organic matter.There must be no SILT or dust in sand. If necessary, sand must besieved from 4.75 mm and 150 micron IS sieves, washed and dried for72 hours before use.Sand must be stored separately from coarse aggregate or bajri orlime etc. on a clean and hard surface. Moist or wet sand must not beused in construction.5.2.5 Water - The water used for both mixing and curing of concreteshould be free from impurities, injurious amounts of acids, alkalis,salts, and organic matter. Potable water is considered satisfactoryfor mixing concrete. The water should be colorless and free from anysmell. The presence of chlorides and sulphates are injurious toreinforcing bars as they may be corroded.5.2.6 Steel Reinforcing - Vertical reinforced columns should be placed inall masonry walls with a maximum dimension between columns of16'-0”.All exterior walls and interior walls should be reinforced. All cornersand junctions should be reinforced and core filled. Reinforce and tiewindows and door jambs into lintels.Fix all vertical reinforcement to foundation and belt course.Fix all vertical reinforcement to the ring beam. Placehorizontal reinforcement every three courses.53