生石灰掺量对轻质蒸压加气混凝土性能及水化产物的影响

Influence of quicklime dosage on lightweight autoclaved aerated concrete property and hydration products

通过测试加气混凝土的体积增长曲线与砌块的基本力学性能,探讨了生石灰掺量对加气混凝土生产性能与使用性能的影响;通过XRD和SEM研究了生石灰掺量对加气混凝土水化产物组成与形貌的影响。结果表明,粉煤灰-水泥-生石灰体系加气混凝土中生石灰掺量越大,浆体初始扩展度越小;生石灰掺量对料浆最终发气体积的影响需综合考虑其对铝粉膏反应速率与浆体稠化速率的影响程度而定;当生石灰掺量从19%增大到29%,钙硅比从0.31增大到0.47,试块平均抗压强度可增大约100%,绝干密度基本不受影响;同时,可促进托贝莫来石的生成,但对托贝莫来石结晶化度与晶粒大小几乎没有影响。

This paper discussed the influence of quicklime dosage on the production performance and usability through the autoclaved aerated concrete slurry gas foaming curve and basic mechanical properties of blocks.Meanwhile,studied the influence of different quicklime dosage on the composition and morphology of hydration products through X-ray diffraction analysis and scanning electron microscopic analysis.The results show that in the cement-fly ash-lime system autoclaved aerated concrete,the larger dosage of quicklime the smaller initial extended degree the slurry presents.The influence of quicklime dosage on the final slurry volume depends on comprehensive consideration of its influence degree on aluminum paste reaction rate and slurry thickening rate.With the quicklime dosage increasing from 19％ to 29％,calcium to silicon ratio change from 0.31 to 0.47,the final blocks has nearly 100％ amplification on its average compressive strength,but no effect on its dry bulk density.Meanwhile,the increasing of quicklime dosage has an effective promotion on the forming of the main hydration products-tobermorite,but it almost make no difference of tobermorite＇s crystallinity and crystallite size.