Recently Four Corners featured a story on what some have termed ‘Australia’s apartment building crisis.’, The investigation was in relation to the increasing amount of apartment building defects including cracks and waterproofing issues which have been gaining public attention following the evacuation of the Opal and Mascot towers in Sydney.
Over the last 20 years more than 650,000 apartments have been built in Australia and according to the ABC, a recent study of apartment building defects found that more than 70% of the buildings examined in Victoria, New South Wales and Queensland had at least one defect in multiple areas.
While building ministers have recently committed to implementing construction industry reforms, these reforms won’t help addressing the existing defects in buildings; and while some defects are immediately apparent, it may take years before others begin to emerge.
It won’t be surprising to anyone working in the concrete industry that one of the more common defects reported in the media is cracks in concrete. Concrete is the most widely used construction material in the world and although its strong in compression, it is susceptible to cracking.
While mixing together cement, water and aggregates might sound simple, there are a wide range of factors which can influence cracking including the exact materials and admixtures, design details, construction methods, service loads and exposure conditions (both during placement/curing and in the longer term).
Cracks in concrete areas are sometimes expected by the designers and not all cracks are cause for concern. But when crack sizes exceed the designed limits or where the designed limits are not appropriate for the intended application and exposure conditions, they often cause problems.
Even non-structural cracks and those which do not immediately impact the load bearing capacity can affect a building’s serviceability or durability. For example, atmospheric carbon dioxide and wind-blown chlorides can penetrate minor cracks on building facades causing the reinforcement to corrode.
Over time this causes even more deterioration, posing a public safety risk and increasing the cost of repairs exponentially. When cracks occur it’s important to determine whether they pose a risk to the durability, serviceability or load bearing capacity of the building and take appropriate action if they do.
Cracks can be assessed, monitored for safety and repaired by those with appropriate equipment and understanding. Infracorr use a range of techniques in the assessment and monitoring of cracked concrete, including visual inspection, non-destructive testing, physical and chemical testing of samples, strain and vibration sensors, and more.
Crack repairs may include resin injection, stitching with metal rods, routing and sealing, or simply coating. While it’s cheaper to get it right at the time of construction, the early identification, assessment and repair of cracks does not have to cost a fortune…although it may save you one in the future.
For more information on assessment or repairs contact us to find out more.