How to Check Quality of Sand on Site?

Quality of Sand on Site:

Sand is one of the most important constituents of concrete. The main purpose of mixing sand (fine aggregate) in concrete is to fill the voids between Coarse aggregate. And the voids between fine aggregate is filled with cement. Sand bulks the concrete and helps to increase the workability of concrete.

Sand is formed by the weathering of rocks. Well, different regions use the variety of sands (Pit sand, River sand, Sea Sand) in construction according to the availability. A good fine aggregate used in construction should be well-graded (all particles that have almost the same size).

The fine aggregate used for construction should pass 4.75mm sieve and retain on 150 microns sieve.

Below mentioned tests are the simple tests that you can perform quickly on-site to find out the quality of Sand. These tests include checking the properties of Sand which affect the strength and the quality.


Tests for finding the quality of the sand on-site:-

Excessive clay / Silt:

The presence of clay in Sand makes the sand cohesive, the good quality of sand should have fewer traces of clay in it.
Presence of excessive clay can be determined in two ways:
For testing the presence of clay in the sand, Take a glassful of water and add some sand to it. Shake it vigorously and allow the sand to settle. Check whether an apparent layer is formed on the sand. Good quality of sand should have less than 8% of clay in it.
Hold some dry sand and drop it. If the Sand adheres to your palm, then it has Clay.

Presence of Organic Impurities in Sand:

For detecting the presence of organic impurities in fine aggregate. Take a Sample of sand and add it in Sodium Hydroxide [NaOH] Solution, Stir the solution for few minutes, if the color of solution changes to brown, then the sand has organic impurities which are not suitable for construction. Good quality of sand shows a lighter color when it is mixed with NaOH solution.

Presence of Excessive moisture content / Bulking of Sand:

The presence of excessive moisture content in sand causes an increase in the volume of sand. Fine Aggregate Which contains more than 5% of moisture content in its volume is not suitable for construction purposes.