早期养护条件对水泥石碳硫硅钙石型硫酸盐腐蚀的影响

研究了早期高湿度空气养护、水中标准养护及密封养护对水泥石碳硫硅钙石型硫酸盐腐蚀的影响。采用X射线衍射（XRD）、傅立叶转换红外光谱（FTIR）和扫描电子显微镜（SEM）等方法分析了水泥石经180 d硫酸盐侵蚀后的腐蚀产物。结果表明,早期高湿度空气养护,水泥石碳化生成的CaCO3填充于孔隙中,使表层结构更加致密,阻碍了SO4^2-等有害离子侵入,延缓了水泥石碳硫硅钙石型硫酸盐腐蚀过程。比较而言,早期密封养护,水泥水化不充分,水泥石内部缺陷相对较多,SO4^2-等有害离子容易侵入,水泥石碳硫硅钙石型硫酸盐腐蚀最为严重。

Effect of Initial Curing Conditions on Thaumasite Form of Sulfate Attack of Cementitious Materials

The effects of initial high humid air-curing,standard water-curing and sealed-curing on thaumasite form of sulfate attack（TSA） of cement-based materials were studied.The Erosion products after 180 days attack in sulfate solution were analyzed by the way of X-ray diffraction（XRD） and fourier transform infrared spectroscopy（FTIR）.And it was found that the TSA of the cement stone was delayed in high humid air resulting from that CaCO3 generated from carbonation was filled in the pores of the specimens,forming a compacted surface and restricting SO42-intrusion.In comparison,the extent of TSA of the specimens cured in sealed condition was most severe resulting from that large amount of inter-defects in specimens for the lower hydration degree,and SO42-ions could intrude into specimens more easily.