Reinforced Autoclaved Aerated Concrete (RAAC) is a lightweight material primarily used in flat roofing, as well as in floors and walls, between the 1950s and 1990s. It offered a costeffective alternative to traditional concrete, with faster production times and easier installation. RAAC is aerated, meaning it has a "bubbly" texture, similar to an Aero chocolate bar. However, it has a limited lifespan of around 30 years and is less durable than standard concrete. Its structural behavior is quite different from that of traditional reinforced concrete, and it is vulnerable to failure when exposed to moisture. The bubbles in the material can allow water to penetrate, causing the reinforcing rebar to decay, rust, and weaken.