An investigation of steam curing pressure effect on pozzolan additive autoclaved aerated concrete

Abstract

Autoclaved Aerated Concrete (AAC) is a porous light weight concrete obtained by adding a pore-forming material to a mixture made of finely pulverized siliceous aggregate and inorganic binder (lime and/or cement) and hardened by steam cure. In this study fly ash was used instead of siliceous aggregate and experiment samples were obtained by adding 3%, 6%, 9%, 12% silica fume to the cement. Samples were cured under 156 degrees C and 4 bars and 177 degrees C and 8 bars, and were investigated for compressive strength, bulk density and ultrasound pulse velocity to determine their mechanical and physical properties. Microstructure of samples was observed by using SEM and XRD techniques. Samples' bulk density values and compressive strengths are changing between 0.6-0.7 kg/dm(3) and 2.5-4.4 MPa respectively.