Durability variations in reinforced autoclaved aerated concrete (RAAC) – extended abstract

Abstract

Reinforced Autoclaved Aerated Concrete (RAAC) was a very common form of construction in the UK and elsewhere in the 1970s, and many of the buildings are now coming to the end of their design life. Although much is known regarding new RAAC (and AAC), many concerns exist regarding their durability, hence the current structural integrity of 40-50 year old RAAC panels, many of which are in use in critical infrastructure such as hospitals, schools and government buildings. Anecdotal evidence and preliminary site observations suggests that there is considerable variation in material properties between different RAAC panels, within the same structure, and across different structures, locations and ages. The aim of this research therefore was to investigate and understand the variability in surface resistivity, sorptivity, permeability, compressive strength, and density of RAAC across a single 2400mm panel, amongst panels from the same structure, and amongst different structures, locations and ages. The research is expected to demonstrate considerable variability in properties and performance, which will have significant implications for the repair, monitoring and management of these critical infrastructure.