INFLUENCE OF QUARTZ PARTICLE-SIZE ON THE CHEMICAL AND MECHANICAL-PROPERTIES OF AUTOCLAVED AERATED CONCRETE .2. FRACTURE-TOUGHNESS, STRENGTH AND MICROPORE

The development of mechanical properties of autoclaved aerated concrete (AAC) block was investigate using ground quartz of different particle sizes. The samples were prepared at 180 degrees C under saturated steam pressure for various times from 0.5 to 64 h. With increasing tobermorite formation, the compressive strength, Young's modulus and fracture energy increased for the samples made-using the coarser quartz, and decreased for the samples made using the finer quartz. After the completion of tobermorite formation, the coarser quartz yielded the higher compressive strength, Young's modulus, fracture energy and crack growth resistance. Using the finer quartz, gyrolite was formed by the decomposition of tobermorite after 64 h autoclaving, reducing the compressive strength and Young's modulus with changes in the micropore size distribution.