Question
What are the key methods used for concrete testing?
Answer
There are a number of methods of testing concrete throughout the construction process. The first important test, before the concrete has set, is the slump test. This is used to check that the cement mix has the correct water content and holds its shape correctly. Concrete is scooped into a conical mould which is then lifted, and used to measure how far the top of the concrete slumps. When too much water is used, the concrete collapses and loses its shape; when not enough is used, the concrete holds its shape and does not slump, meaning that it will not be workable.
Samples of concrete can also be formed into testing cubes, cylinders and beams. These will then be allowed to set with the rest of the concrete and will be tested to destruction in order to find the maximum load bearing potential, as well as the maximum shear load, from the beam.
There are also a number of non-destructive testing methods used to identify cracks and imperfections in concrete. These include simple observations, but also the use of ultrasound and radar, as well as magnetic sensors to find reinforcement in concrete.
