Spalling Concrete

We often receive calls regarding Spalling Concrete when the defect appears in Building Inspection Reports. Below is a brief explanation of the causes, effects and rectification needed to overcome the problem.

Spalling concrete, most commonly referred to as concrete cancer and is largely due to a natural deterioration process called carbonation. Carbon dioxide in the air diffuses into the concrete and reacts with the alkalis in it. The concrete becomes carbonated and this allows the embedded steel bars to corrode. The bulging and cracking of the surrounding concrete is caused by the force exerted due to the expanding steel bars. The spalling concrete should be repaired as soon as possible before the steel bars corrode further and damage larger areas. The early treatment of spalling concrete will not only cause less damage to your building, but will be less expensive to repair.

Spalling concrete is rectified by, removing the Spalled Concrete areas to expose the steel bars, ensuring that all surfaces of the steel bars are exposed and can be treated, then cleaning, de-scaling and the application of a primer/sealer as a rust inhibitor to the exposed Steel Bars. The aim is to prevent oxygen and moisture diffusion, a good coating of the correct primer/sealer will slow down the carbonation process and minimise the ingress of oxygen and moisture into the concrete, helping to prevent the corrosion. Immediately sealing any cracks in the building as well as having the building painted regularly can reduce the occurrence of this problem.

We hope this has given you a better understanding of this defect, as always you can call or email us to obtain further information.