A concrete cube test involves taking a sample of freshly mixed concrete, letting it cure, then crushing it and measuring its compressive strength. Many concrete suppliers carry out this process at a certified test house, away from their facilities
What happens during a concrete cube test?
A typical concrete cube test follows these main steps:
Take a sample of freshly mixed concrete
Pour the concrete into 3 cube moulds – The sample concrete is poured into 2 or 3 cube moulds (depending on the customer’s requirements). The concrete in each mould is then filled, levelled, compacted and tampered to related standards requirements. Each cube is taken to our temperature-controlled lab, where it is kept for 24 hours, before being cracked and put into our water tanks to cure.
Let the concrete cubes cure – The cubes are kept in temperature-controlled water tanks for 1–4 weeks.
Crush the cubes to test their strength – When each cube is ready for testing, it is put into a concrete crusher. This machine exerts force onto the cube until it breaks. The rate at which it crushes is measured, and this is its compressive strength.
When should the cubes be tested?
The concrete should be tested after 7 days and after 28 days. That’s why 2 or 3 cubes are taken – so that the concrete can be measured after different lengths of time.
The concrete cube test formula, for testing the compressive strength of any material, is as follows:
Compressive Strength = Load / Cross-sectional Area