Autoclaved Aerated Concrete (AAC) Blocks

Autoclaved aerated concrete (AAC) has proven to be a sustainable material that may reduce carbon emissions, energy use, and address housing shortages. Despite these benefits, its use as a walling unit in African construction projects remains limited or non-existent. This study evaluates the acceptability and key drivers of AAC blocks as a walling material. To achieve this, seventeen online surveys were emailed to South African construction practitioners in five provinces, while 99 were self-administered in Lagos, Nigeria, and analyzed with statistical tools. The survey found that top AAC blocks in South Africa use OPC (grades 52.5 and 42.5), AP, RHA, POFA, or PFA. Lightweight properties, eco-friendliness, and heat resistance are key uses in Nigeria, whereas fire insulation, lightweight, thermal absorption, and flexibility are valued in South Africa. The study concludes that AAC manufacturers beyond the top four types will have limited patronage. While lightweight properties drive AAC block adoption in both countries, other elements differ in importance. This choice benefits tall constructions by lowering foundation costs.