No abstract

Autoclaved aerated concrete (AAC) is commonly used as a modern, energy-efficient construction material in Nur-Sultan, Kazakhstan—the second-coldest national capital in the world after Ulaanbaatar, Mongolia. The autoclave curing method used to manufacture the AAC has potential risks and is environmentally costly because of its high-pressure and -temperature operation. Therefore, for phase I and II studies, non-autoclaved aerated concrete (NAAC) was cast, and its properties were evaluated in terms of compressive strength, density, porosity, and thermal conductivity. Moreover, the thermal conductivity prediction model of NAAC was successfully developed. In this Phase III study, the energy behavior of the NAAC was evaluated by energy simulation for a typical two-story residential house model in Kazakhstan. Different wall materials, such as fired brick and normal concrete, were adapted to compare the energy performance of NAAC. Finally, the annual heat loss and amount of heat transferred through the wall of the house were calculated to cross-check the energy-saving effect of NAAC. It was found that the NAAC conserved energy, because the heating and cooling loads, annual heat loss, and amount of heat transfer of NACC were lower than those of fired brick and normal concrete.

Aerated concrete (AC) is widely used in the construction industry due to lightweight and advanced thermal properties. In this research, thermal conductivity (λ) of non-autoclaved AC was characterized with Response Surface Methodology (RSM). The effect of fine aggregates with different Al2O3 contents on the minimal λ value was analyzed using RSM. Test results show that sand with higher Al2O3 content has more influence on lower λ of AC. The regression models were significant and applicable to analyzation and prediction of λ of AC with good accuracy.