If you have worked in an industrial or commercial building where an exposed concrete floor is the surface the business operates from, then you have probably come across crazing. It is an irregular pattern of fine cracks in the concrete which is known as surface crazing.
In fact, they tend to be more visible when the floor gets wet, as the very fine cracks trap moisture and dust. However, unless you are tasked with the maintenance or repair of concrete floors, you may not realise there is a name for this particular feature.
It is an inherent feature of power trowelled concrete floors which is typically considered to affect the appearance of the floor and not its performance.
Before doing anything about fine cracks, it is important to be sure the cracks are indicative of crazing and are not confused with mid-panel cracking due to restrained contraction. The treatments are very different.
If the cracks are the result of crazing, the good news is they are not considered to be a structural or serviceability issue that will affect the performance of the floor slab. Therefore, there is no need to worry about having repairs done to a floor surface that is only suffering from crazing.
Other cracks that are not considered to be crazing, can have an effect on structural or serviceability of the floor and generally require to be assessed and treated as soon as possible to prevent further degradation.
The mechanisms leading to Crazing are not fully understood and this means that it’s not really possible to recommend measures that can reduce its occurrence. What we do know is that crazing is a result of differential shrinkage between the surface layer and the underlying concrete. We also know that crazing tends to appear less in concrete with lower water content.
As crazing is not indicative of serious structural issues, there are currently no appropriate treatments. If the appearance of crazing is deemed unsightly and not acceptable, then a surface coating can be applied to provide a uniform appearance to the floor surface.
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