Investigations of forming mixture parameters of autoclaved aerated concrete with nanoadditives

Abstract

Impact of some nano additives, such as amorphous SiO2 (AS) of pozzolanic properties and carbon fibers (CF) reduced to nanosize particles on autoclaved aerated concrete (AAC) forming mixtures, the following parameters were investigated: changes in consistence of binding material during hydration, spread ability, expansion and temperature of mixture, plasticity strength. The investigations were carried out with AAC forming mixture where 10 % lime was replaced by equivalent content of Portland cement. Upon completion of investigations, it was established that the optimal replacement of sand by AS was 1.0 % resulting in increase of temperature of AAC forming mixture by up to 2.1 %, expansion by up to 11.0 %, ultrasonic impulse velocity (UIV) by up to 3.0 % and plasticity strength by up to 271.4 %. Meanwhile the optimal replacement of sand by CF was 0.1 % resulting in decrease in temperature of AAC forming mixture by up to 1.5 %, expansion by up to 16.0 % and increase in UIV by up to 2.0% and plasticity strength by up to 152.9 %.