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

The development of mechanical properties of autoclaved aerated concret e (AAC) block was investigate using ground quartz of different particl e sizes. The samples were prepared at 180 degrees C under saturated st eam pressure for various times from 0.5 to 64 h. With increasing tober morite formation, the compressive strength, Young's modulus and fractu re energy increased for the samples made-using the coarser quartz, and decreased for the samples made using the finer quartz. After the comp letion of tobermorite formation, the coarser quartz yielded the higher compressive strength, Young's modulus, fracture energy and crack grow th resistance. Using the finer quartz, gyrolite was formed by the deco mposition of tobermorite after 64 h autoclaving, reducing the compress ive strength and Young's modulus with changes in the micropore size di stribution.