Optimization of construction and technical properties of non-autoclaved aerated concrete

From the point of view of practice the issue of eliminating the disadvantages of non-autoclaved aerated concrete (NAAC) in comparison with the autoclaved concrete (AAC) in terms of strength-density ratio and shrinkage is relevant. The working hypothesis was that it is possible to obtain non-autoclaved material of improved quality from a mix of cement and high-calcium ash from thermal power plants using chemical additives that reduce degradation caused by hydration of burnt lime contained in the ash. In this work 14 samples of high-calcium ESP ash, Portland cement CEM II and chemical additives, sodium chloride and sulfate, were used. The phase composition of the hydration products of compositions was determined and the regularities of the phase composition effect on the properties of NAAC were established. It is shown that the introduction of NaCl or Na2SO4 promotes the formation of concrete with higher construction and technical properties.

Author: G.I. Ovcharenko, Y.V. Gilmiyarova

Section: Waste utilization

Keywords: non-autoclaved aerated concrete, high-calcium ash from thermal power plants, phase composition of hydrates, differential thermal analysis