Properties control in autoclave aerated concrete by choosing of pore forming Al-agent

Abstract

Autoclave aerated concrete is state of art high-performance construction material due to unique combination of thermal and strength characteristics achieved by cellular structure, in general. In this paper effect of dispersity and reactivity of gas forming Al-component on carrying out of such important processes as forming of optimal pore structure providing reduced density and required compressive strength in aerated concrete. The results of kinetics of gas evolution in different alkali media in the binder under temperature and effect of Al-component were obtained. Volume of gas evolution was measured with gasometric method. This method is based on variation of volume of hydrogen evolution caused by reaction between Al-component and Ca(OH)2. According to experimental and calculated data it is reasonable to use polydispersed Al-component containing nanoparticles. It allows realization gradual gas evolution, directed formation of required shape and size of pores in cellular structure leading to reduction in density by up 16% and reducing in water absorption capacity by 41% as well as increasing of compressive strength by 28% and increasing of humidity resistance.