硅钙基固废原料配比及蒸养条件对硅酸钙板力学性能的影响

研究协同利用硅钙渣、粉煤灰、水泥和脱硫石膏制备硅酸钙板时,原料配比、蒸养条件对硅酸钙板力学性能、水化产物的影响,并利用XRD、IR和SEM表征了原料的协同水化历程和水化产物的微观结构和表面形貌.试验结果表明:最佳原料配比为硅钙渣60%、粉煤灰24%、水泥10%和脱硫石膏6%;最佳蒸压养护条件为蒸养温度180℃,恒温蒸养时间8 h,硅酸钙板抗折强度满足国家标准强度的D1.3的Ⅱ级要求;随着蒸养温度升高,原料水化依次生成C-S-H凝胶、托贝莫来石和针状硬硅钙石,大量托贝莫来石和硬硅钙石的生成使得硅酸钙板的强度得以提升.

Effect of Raw Material Ratio of Silicon-Calcium Based Solid Wastes and Autoclaved Curing Conditions on Mechanical Property of Calcium Silicate Board

The effect of raw material ratio and autoclaved curing condition on mechanical property and hydrated products of calcium silicate board was studied synergistically using calcium silicate slag(CSS), fly ash(FA),ordinary Portland cement(OPC)and desulfuriztion gypsum(DSG)as raw materials to prepare calcium silicate board.Moreover, the synergistic hydration process and microstructure of hydrated products were investigated by XRD, IR and SEM measurements.The results show that the optimal raw material ratio is 60% CSS, 24% FA, 10% OPC and 6% DSG; the optimal autoclaved curing condition is that curing temperature at 180 ℃ and holding time in 8 h.The flexural strength of calcium silicate board met the class-two requirement of Chinese Standard D1.3.Hydrated calcium silicate gel(C-S-H(I)), tobermorite and acicular xonotlite are successively generated from hydration of raw materials when improving the curing temperature.The strength of calcium silicate board is promoted by generation a large amount of tobermorite and xonotlite.