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In this article, we will discuss how to check the quality of sand on site.
Sand can be defined as the mixture of small fine grains of granular materials and rock.
It is also commonly defined by size i.e. it is finer than gravel and coarser than silt ranging in size from 0.06mm to 2mm.
Most types of sand are formed by the erosion of soil, weathering of the rocks, broken pebbles, and gravels carried by rivers, streams, etc.
The basic composition of sand mostly includes unconsolidated granular materials consisting of either rock fragments or mineral particles or oceanic materials.
It is mainly made of silicate minerals and silicate rock granular particles. The most dominant constituent is quartz because it consists of highly resistant properties to weather. Quartz is also commonly referred to as silicon dioxide.
A. How to Check the Quality of Sand on Site?
The fine aggregate employed for construction should pass the 4.75 mm sieve and retain on 150 microns sieve.
1. Excessive clay / Silt
The existence of clay in the sand causes the sand cohesive, the good quality sand should have rarer traces of clay in it.
The existence of excessive clay can be chosen in two manners:-
a. For sampling the existence of clay in the sand. Bring a glassful of water and add some sand to it. Jerk it vigorously and permit the sand to settle. Inspect whether an apparent layer is created on the sand. Good quality sand should have less than 8% of clay in it.
b. Carry some dry sand and drop it. If the Sand sticks to your palm, then it has Clay.
2. Existence of Organic Impurities in Sand
For noticing the existence of organic contaminants in fine aggregate. Grab a sample of sand and add it to Sodium Hydroxide [NaOH] Solution, Stir the solution for a few minutes, if the color of the solution shifts to brown, then the sand has organic impurities which are not appropriate for construction. Good quality sand offers lighter color when it is mixed with the solution of NaOH.
3. Existence of Excessive moisture content / Bulking of Sand
The existence of excessive moisture content in sand causes increases in the volume of sand. Fine Aggregate which contains more than 5% of moisture content in its volume is not appropriate for construction use.
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