THE IMPORTANCE OF SAND IN CONCRETE

Sand contributes to the strength of concrete by filling the gaps between the aggregate and creating a solid structure.

The purpose of concrete is to support substantial weight. It is the aggregate that carries this weight, the cement that binds it together and the sand that assures there are no holes in the final material.

Sand is considerably hard and resilient to weather. This makes it an ideal structural material for mixing into concrete.

To make strong and durable concrete you need: cement, sand, aggregate and water.  The ratio you use will depend on your purpose.

A common ratio is:

• 1 part cement
• 3 parts sand
• 3 parts aggregate (gravel)
• 0.5 water (approx.).

This will give you a concrete with roughly 3000 psi.

The volume of water is approximate because the amount of water can affect the strength of your concrete. Essentially the less water you use, the stronger the concrete. However, dryer concrete is difficult to work with. Gradually add your water to your dry mixture until it reaches the desired consistency.

Accurately measure your ratios using the same bucket or wheelbarrow, depending on volumes. Keeping the measuring device and ratios consistent allows you to mix in batches while giving a reliable mix for the whole job.

Using the ratio above, your concrete should reach full strength in about 4 weeks. For greater strength, it is important to “cure” your concrete. Curing will also reduce the risk of cracks and minimise permeability. Curing simply involves keeping the concrete wet for the first week.