Reinforced Autoclaved Aerated Concrete (RAAC) is a lightweight form of concrete frequently used in the UK between the 1950s and 1990s. RAAC has been found to have a limited lifespan, with a risk of failure after 30 years. The Environment Agency needed an effective and efficient approach to understand and reduce the risk of RAAC in critical flood protection assets. 

We worked with the Environment Agency's Innovation Delivery Group to develop a three-step process for rapid, robust and consistent RAAC risk assessment.  

Drawing on our extensive experience in RAAC investigations and using Arup’s Fuse digital platform, we analysed all 500,000 Environment Agency assets for characteristics indicating possible RAAC. This process identified 1,450 assets for further investigation through data-driven desk studies. Ultimately, we found 240 assets requiring physical inspections, which were completed within eight weeks. 

Using our digital platform enabled us to apply our engineering judgement at scale – quickly screening thousands of assets. Frictionless data-sharing between Arup and Environment Agency teams supported efficient collaborative working. A 95% reduction in the number of site inspections meant the Environment Agency could more quickly ensure safety for staff and visitors to its sites, while reducing cost and carbon emissions for the assessment programme. 

A river running through a grassy area.

Partnering with the Environment Agency, we developed a three-step RAAC risk assessment, leveraging our digital platform, Fuse, to efficiently analyse 500,000 assets.

A small building in a grassy area.

Our data-driven approach enabled targeted investigations, reducing inspections by 95% while ensuring safety and sustainability.