Why The Current UK Concrete Crisis Could Take Years To Solve
Amid concerns that the school concrete crisis could take up to two years to resolve, experts are warning that the problem will escalate to include other public buildings such as hospitals and courts. Over 156 schools have had to fully or partially close just weeks before the start of term, and it is estimated that this could just be the tip of the iceberg. The current problem with Reinforced Autoclaved Aerated Concrete (RAAC) has been known about by structural engineers since the 1990s. The material was invented in Sweden in the 1920s as an innovative lightweight concrete, and widely used to manufacture roof panels for flat roofs between 1950 and 1990 in the UK. RAAC contains air bubbles instead of the coarse aggregate used in regular concrete, and this makes it lighter but also weaker and prone to cracking and water damage. When it has been correctly installed and maintained, it is deemed safe to use, but this has not always been the case. Many of the schools now affected by the crumbling concrete crisis were built in the 1960s or 70s, and are well past the recommended life span of 30 years for RAAC as a safe construction material. Professor Goodier, an expert in Construction Engineering and Materials at Loughborough University said: “Like many countries, the UK has an old building stock, which needs to be adequately repaired and maintained. In the post-war period the country built numerous new buildings with a variety of different methods, many of which are now feeling their age.” He added: “One innovative construction material and process was RAAC: Reinforced Autoclaved Aerated Concrete, which is an aerated lightweight cementitious material with no coarse aggregate; the material properties and structural behaviour therefore differs significantly from ‘traditional’ reinforced concrete.” “Tens of 1000s of these structural panels exist across a broad cross-section of buildings, many constructed in the 1960s and 70s, and many are showing signs of wear and tear and deterioration. The vast majority form the roof of the structure, usually flat, and hence are difficult to access, survey, maintain and replace.” It is not just schools that are affected by the RAAC crisis, but also hospitals. NHS England has said that it intends to remove all RAAC panels from its estate by 2030. A National Audit Office report found that 41 buildings at 23 NHS Trusts contained RAAC, and seven hospitals had RAAC present throughout the entire building. RAAC is also thought to be present in office blocks, shopping centres, and homes. However, there is no central register for the use of RAAC in UK buildings, so going forward any building suspected to contain the material will have to be inspected by a structural engineer. Looking for concrete padstone blocks? Please visit our website today.Trackback from your site.
