River Sand

 It is naturally available and extracted from the river banks or river beds.

– The shape of natural sand is rounded and has a smooth surface.

– Moisture is generally present in between the particles. Hence, effects the assumptions of concrete mix design and quality of concrete.

– The compressive strength, as well as the flexural strength of concrete made from natural sand, are lower than Crushed sand.

– It contains silt as river water contains it due to the erosion of soil in its catchment area. Hence it needs washing on site.

– Oversized materials are expected in natural sand and hence need screening on site.

– It may contain marine products such as grass, algae, clay lumps, bones, shells, mica, etc. which are harmful to properties of concrete.

– It is harmful to the environment. It reduces the groundwater level and rivers water gets dried up.

– It has a high probability of adulteration because of acute shortage. River sand adulteration with saline sea sand is common in coastal areas.

– It is recommended for RCC, plastering and Brick/Block works

– The quality of natural sand deferrers though they may be from the same river bed.

– Mostly conforms to zone II and zone III

– The presence of silt and clay in the sand reduces the setting time of cement and make concrete and mortar weak and holds the dampness.

– The requirement for cement is more.

– Water table level gets reduced due to dragging of the sand from the river and the roots of the tree may not be able to get water.

– In the absence of sand in the river, water gets evaporated due to direct sunlight.

– The slump is more.