Act quickly to prevent future expense when it comes to
concrete repair
Scott Jensen I Director, Roof & Building Service
Exterior concrete cracks on your large residential apartment buildings should never be ignored. Even seemingly insignificant concrete cracks or areas of blistering paint can actually be masking a larger problem of concrete spalling – which can become more complicated (and as a result, more expensive) the longer you put off remediation work.
Concrete cracks are a normal occurrence – but must be repaired immediately
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t is the very nature of concrete structures to crack to a minor or major degree. Cracking indicates that the structure has been forced to absorb the energy of some form of stress. It does not mean the structure has failed, in fact on the contrary, any cracked concrete structures can be repaired effectively and, most often, permanently, provided the structure has not been wholly deformed and the original cause of cracking has been mitigated. However, it is important that even the smallest cracks are repaired immediately, as they can result in the ingress of chlorides and other minerals that will lead to concrete spalling (also known as concrete
cancer). Many resort owners and managers believe that it’s sufficient to apply a flexible sealant to the cracked area – but this shortterm fix certainly isn’t effective, and will lead to serious problems in the long-term. Instead, best practice is to identify the cause of the cracking so that the most appropriate remediation solution can be proposed.
Early concrete crack detection is positive prevention Rectifying repairable cracks will: • Restore structural and/or design strength to the cracked concrete structure • Eliminate serious spalling of concrete initiated by cracking and aggravated by temperature cycling • Prevent corrosion of reinforcing steel and pre-stress tendons by encapsulating them against moisture or water contact • Prevent water ingress through concrete structures • Repair concrete architecturally without any of the unsightly surface marks caused by standard surface crack repairs There are usually two causes associated with concrete cracks and spalling: the first is close proximity to coastal areas, and the second is pressure on the concrete.
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Identifying and preventing concrete cracks and spalling in coastal environments Concrete spalling is a common issue in coastal environments due to carbonation and chloride levels – and it regularly affects large apartment blocks. It is especially common when a breakdown in an area of concrete’s protective coating has occurred, since the concrete is then exposed to the elements. Every occurrence of concrete spalling in this type of environment is unique, and must be examined by a professional to determine the right course of action. One option for the mitigation of concrete spalling is ensuring that your building has the correct