ABSTRACT
The aerated concrete manufacturing process consists of the creation of macro-porosity (called introduced porosity) in a micro-mortar matrix made of cement, lime, sand and water with the help of an expansive agent. The agent, generally aluminum powder, reacts with the water and the lime liberated by the hydration of the binder (Wittman 1983). The gaseous release generated by this chemical reaction causes the fresh mortar to expand and leads to the development of pores, which give aerated concrete its well known characteristics: low weight and high thermal performance (Narayanan & Ramamurthy 2000). The widespread utilization of aerated concretes in building as lightweight-bearing elements requires the use of ever more mechanically efficient materials (Cabrillac & Malou 1996). Moreover, the high porosity of aerated concretes, essential to their main function, which is thermal insulation, leads to very poor mechanical strength compared to normal concrete.The quantity of pores and the pores’ distribution mainly influence the mechanical properties (Alexanderson 1979).The most common technique to make up for this lack of strength is an autoclave treatment performed under high pressure and high temperature to create Autoclaved Aerated Concrete (ACC) (Narayanan &
Ramamurthy 2000), but this is economically and environmentally costly (Cabrillac et al. 2006).
