How-to
5 Simple Field Tests to Check Sand Quality at Your Site
Before you accept a load, a few minutes of checking can tell you a lot. Here are five tests anyone can do at the site gate.
You cannot run a full lab analysis on every delivery, but you can catch most problems with simple checks. Here are five that need nothing more than a clear bottle, some water and your eyes.
1. The bottle (silt) test
Fill a clear glass or bottle about half with sand, top up with water, add a pinch of salt, shake well, and let it settle for a few hours. Silt and clay settle as a distinct layer on top of the clean sand. If that fine layer is more than a small fraction of the sand depth, the silt content is too high. This is the single most useful field test.
2. The hand-rub test
Take a handful of dry sand and rub it between your palms. Clean sand leaves your hands only lightly dusty. If your palms come away coated in fine powder or muddy film, the sand carries too much dust or clay.
3. The wet-feel (clay) test
Rub a little damp sand between your fingers. Good sand feels gritty. If it feels smooth, sticky or soapy, there is clay in it — clay holds water and weakens the mix.
4. The colour (organic) test
Organic matter — decayed leaves, roots — interferes with cement setting. A rough indicator: clean construction sand looks grey-to-light-brown and uniform. Very dark or black-streaked sand with an earthy smell suggests organic contamination and should be questioned.
5. The grading glance
Pour some sand out and look at it. Good sand has a mix of particle sizes — some coarse, some fine. If it looks like it is nearly all one fineness (either all dust or all coarse grit), it is poorly graded and will not pack well in concrete.
When in doubt, reject the load
A questionable load of sand is far cheaper to turn away at the gate than to discover after it is cast into a slab. If two or more of these checks look bad, hold the delivery and call your supplier. Reliable suppliers stand behind their material and will sort it out.
Need this delivered to your site?
Wilgro Infra supplies washed M-Sand, P-Sand and graded aggregates across Sarjapur, Hosur, Attibele and all over Bangalore — by the tonne or by the load, with sieve reports on request.