稻壳灰对蒸压加气混凝土性能影响的试验研究

Experimental study on autoclaved aerated concrete using rice husk ash to replace fine sand

以稻壳灰取代磨细石英砂制备蒸压加气混凝土(AAC),研究了稻壳灰掺量及蒸养时间对AAC干密度、强度、导热系数和微观结构的影响。结果表明:掺入稻壳灰将增加拌合物的需水量,同时,降低AAC的强度和干密度。随着稻壳灰取代石英砂的掺量增加,AAC的导热系数下降。在蒸压养护6 h下,稻壳灰掺量对AAC中托贝莫来石结构影响显著。当稻壳灰掺量超过50%时,托贝莫来石由针状和片状转化为小草状。蒸养试验结果表明,采用高活性稻壳灰可降低蒸养时间而不影响AAC的性能。

Using rice husk ash （RHA） as replacement for fine sand to prepare autoclaved aerated concrete （AAC）.This study examines the effects of rice husk ash on the dry density, compressive strength, thermal conductivity and microstructure of AAC produced at tempera~ ture of 180~C for 6h and 16h.The experimental results demonstrated that RHA substitution for sand increases the requirement of water and reduces compressive strength and dry density.Meanwhile, as well as the thermal conductivity.In terms of the microstructure, the highly re- active silica in RHA strongly affected the tobermorite transformation.At 6h of autoclaving time, the needle-like and plate-like tobermorite formed in mixtures containing up to 50% RHA was replaced by a glass-like.The testing results of autoclaving time indicated that AAC containing high contents of RHA can reduce autoclaving time without affecting its properties.