碱矿渣水泥石抗碳硫硅钙石型硫酸盐腐蚀性能

Resistance of Alkali-Activated Slag Cement to Thaumasite Sulfate Attack

研究了外掺10%(质量分数)石粉的普通硅酸盐水泥石和以水玻璃为碱组分的碱矿渣水泥石抗碳硫硅钙石型硫酸盐腐蚀(TSA)性能及硅灰和粉煤灰对水玻璃-矿渣水泥石抗TSA性能的影响.采用X射线衍射(XRD)、傅里叶转换红外光谱(FTIR)等方法分析了水泥石在(5±2)℃,5%(质量分数)MgSO4溶液中浸泡4a的腐蚀产物,并通过压汞法测试了硬化碱矿渣水泥石的孔结构.结果表明:普通硅酸盐水泥石在试验条件下发生了典型的TSA,水玻璃-矿渣水泥石仅受到轻微的石膏型硫酸盐腐蚀,未发生TSA;硅灰等质量取代10%矿渣及粉煤灰等质量取代20%,40%矿渣的试件几乎未受到硫酸盐腐蚀.水玻璃-矿渣水泥石抗TSA性能较好的原因主要是该水泥体系水化产物为低碱度水化硅酸钙,且孔结构优良.

The thaumasite sulfate attack（TSA）of water glass-slag cement,ordinary Portland cement with10%（by mass）of limetsone and the effects of fly ash and silica fume on TSA of water glass-slag cement were studied.The erosion products after immersed in 5%（by mass）MgSO4solutions for four years at 5℃were analyzed by means of X-ray diffraction（XRD）and Fourier transform infrared spectroscopy（FTIR）.The pore structure of hardened paste of water glass-slag cement was tested by mercury intrusion method.The results show that for ordinary Portland cement paste typical TSA occurs and water glass-slag cement stone is suffered from slight sulfate attack caused by gypsum but not thaumasite and specimens with 10%silica fume,20%and 40%fly ash are not attacked by sulfate.Water glass-slag cement has excellent resistance to TSA due to its fine pore structure and its main hydration products are low-alkali hydrous calcium silicate.