How to Test Your Sand For Impurities On Site

Having quality sand for construction purposes can mean the difference between failure and success. Plaster sand, in general, should contain different sized sharp particles, and should be clean – free from silt as much as possible. However, in order to know how ‘clean’ you sand is, you need to test it.

Here’s how to test your sand for any impurities whilst on site:

·         The rub test:

By simply rubbing some of the desired sand between your damp hands, you can determine the pureness of the sand simply by paying attention to the discolouration to your hands. If a slight stain is left behind, the sand is relatively clean. However, the dirtier your hands are, the more impurities are present. In which case, you should move on to find cleaner sand.

·         The decantation test:

Half fill a glass cylinder with your chosen sand, and pour clean water in until it’s three-quarters full. Shake the cylinder vigorously and let it stand for roughly an hour. The sand will settle first, followed by a silt and clay layer if present. Remember, the thickness of the silt should not exceed 6% of the total thickness of the sand, otherwise, the sand needs to be washed or you need to find cleaner sand elsewhere.

Tips:

·         Plaster sand should not contain silt

If your plaster sand contains silt, it can make the plaster weak due to the fact that silt takes the place of the binder, which means it fills the voids where the binder should be added.

·         Plaster sand should contain different particle sizes

The key to a strong plaster mix is using less binder. This can be done by choosing sand that contains different particle sizes, which requires less binder to fill the voids.

·         Plaster sand should be sharp and angular

In order to create a sound structure, your sand needs to be sharp and angular instead of round. Building with round sand will create too much ‘movability’ between the particles. For this reason, sea sand should be avoided at all costs.

Purchase high-quality plaster sand for your next construction project by choosing Sand Shifters as your supplier.

Sources: http://thesustainablehome.net/sand-for-natural-plasters/

http://civilblog.org/2016/02/29/how-to-check-impurities-in-sand-on-site/#