MECHANICAL PROPERTY EVOLUTION DURING AUTOCLAVING PROCESS OF AERATED CONCRETE USING SLAG .2. FRACTURE-TOUGHNESS AND MICROSTRUCTURE

The mechanical properties were investigated for autoclaved aerated con crete (AAC) block samples, prepared using blast furnace slag at 180-de grees-C under saturated steam pressures for various times from 1 to 12 8 h. The mechanical properties of AAC made using slag are comparable t o those made without slag. With increased autoclaving time, the compre ssive strength increases due to the binder effect of the 1.1-nm toberm orite. In contrast, the fracture energy G(F) and resistance to crack g rowth decrease with increase of autoclaving time. This dependency is c aused by the formation of voids around unreacted slag particles.