Cement Energy Environment

69 Pit Sand M-Sand Sand River Sand Figure 1: Classification on Types of Sand Based on Source Figure 2: Pit-Sand being quarried from a source. In classification of sands from source types there are three sub-heads namely - Pit sand, River sand and manufactured sand(M-Sand) respectively as discussed below. Pit sand is a natural and coarse type of sand which is extracted by digging 2-3m underneath the ground. It’s in red-orange color due to a presence of iron oxide around the grains. These sand grains are free from salts. Hence it doesn’t react with the moisture content River sand is obtained from the bank of rivers and river beds. It is usually found in white – grey color and has a very fine quality. River sand is well graded, and it is good for all types of concrete and masonry works. Natural river sand was the cheapest resources of sand. However, excessive mining of river bed to meet the increasing demand for sand in the construction industry has led to the ecological imbalance thereby adversely present in the atmosphere. Due to its superior binding properties pit sand is used in construction. As mentioned above, pit sand is a coarse type of sand and this is not recommended if the sand is coarser than the acceptable limits of 4.75mm IS particle sizes. affecting the environment. River sand has a huge silica content in it. Excessive presence of silica content makes the sand useless for concrete work and responsible for efflorescence on the surface in future. To overcome this, the sand should be tested for silica content before using it. A good sand should have less than 5% of silica in it. Pit Sand River Sand