Sand is a major component of concrete and without the sand, concrete will not function as intended. Its main purpose is to fill the voids between the Coarse Aggregate (popularly known as Stone Chips), while Cement and water bind together sand and stone chips to get concrete as the product. Sand increases the workability of concrete. It even indirectly increases the strength of concrete. Therefore we have listed here some buying tips for sand to be used in construction works. For procurement of sand, following things to be carefully noticed.
1) Sand shall be hard, strong, dense, and durable, clean with uncoated grains.
2) The maximum size of the particles shall be 4.75 mm (3/l6 in) and shall be graded down.
3) The sand shall not contain any harmful materials such as iron, Pyrites, coal, mica, silt, clay, alkali, sea shells organic impurities, loam etc. or in case of reinforced concrete work, any materials which might attack the reinforcement or detrimental to concrete.
4) The silt content shall be within 8%.