混凝土在SO42-和CO32-共同存在下的腐蚀破坏

对西部水工混凝土受地下盐水侵蚀现状进行了现场调查和取样。用X射线衍射、扫描电子显微镜、X射线能量色散谱仪和激光Raman光谱等方法研究了实际运行6a龄期混凝土的腐蚀产物。结果发现：在SO4^2-和CO3^2-长期作用下混凝土的腐蚀产物是由硅灰石膏、钙矾石、石膏和方解石组成的一种白色稀泥状混合物，经对该混合物分析证实处于低温、高湿、硫酸盐、碳酸盐条件下，混凝土发生了硅灰石膏型硫酸盐侵蚀破坏。

CORROSION DAMAGE OF CONCRETE IN PRESENCE OF SO42- AND CO32-

A site survey with corresponding sampling was carried out for an attacked concrete exposed to ground water, which contains substantial salts. The degraded concrete component at 6 years old was taken from a hydraulic structure in the western China. Samples selected from the site were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X-ray (EDAX), and laser Raman spectroscopy methods. The results show that a white mushy mixture consisting of thaumasite, ettringite, gypsum, and calcite occurs in the residual concrete due to a long-term exposure to SO_4~(2- )and CO_3~(2-) in the ground water. It is validated that the thaumasite form of sulfate attack (TSA) occurs in the field concrete, which has been undergoing at a low temperature, an adequate humidity, as well as a sulfate and carbonate attack.