Water absorption of autoclaved aeratedconcrete made with the use of fly ash

The results of determining the water absorption of autoclaved aerated concrete made with the use of fly ash are presented. The authors derived the dependence of the water absorption of aerated concrete on its average density under study range from 500 kg/m3 to 600 kg/m3. It was experimentally established that the water absorption of aerated concrete with an average density of 500 kg/m3 (D500) by mass is 84.4 %, by volume is 41.2 %, aerated concrete with an average density of 600 kg/m3 (D600) – 72 % and 43.4 %, respectively. A day after immersion in water, aerated concrete D500 gains an average of 75.5 % of the full water absorption, aerated concrete D600 - 78.3 %. Autoclaved aerated concrete made with the use of fly ash achieves full water absorption after seven weeks of testing. The difference in water absorption between aerated concrete with an average density of 500 kg/m3 and 600 kg/m3 by mass and volume is 17.2 % and 5.3 %, respectively. The closed porosity of the aerated concrete D500 is 40 %, and that of the D600 is 33.4 %.