Spalling Concrete Repair

When it comes to spalling concrete repair, there may be more to know about the phenomenon and the problems it can cause in the long run. Spalling is the flaking or chipping of material from artificial surfaces like concrete. If you see any concrete surface in your home or office that displays chipping, flaking, or missing large chunks exposing the coarse aggregate below, you have a concrete spalling problem.

While this is the visual indicator of the problem, a deeper dive is needed to understand the causes. Several chemical and physical processes might contribute to concrete spalling and factors like the environmental conditions and the original mixing technique of the concrete can play important roles. Most common causes of concrete spalling include:

• The corrosion of the reinforcing steel or rebar. The corrosion produces rust that results in volume expansion, putting pressure on the concrete. This extra pressure causes the concrete to spall.
• An alkali-silica reaction can take place between cement pastes which are alkaline in nature and the silica in concrete aggregates which can be reactive. This reaction also results in volume expansion and, over time, spalling.
• Water that has penetrated into the concrete can freeze and thaw with the seasons. During the winter, the freezing of the water can cause it to expand in volume putting pressure on the concrete which can result in spalling.

Apart from these main causes, spalling can also occur from fire exposure, the use of low-quality concrete, badly constructed joints, and bond failure.