水泥基材料溶蚀试验研究进展

简要综述混凝土溶蚀机理试验研究、溶蚀过程主要影响因素以及溶蚀机理。宏观溶蚀试验主要有接触溶蚀和渗透溶蚀两种方法;采用电化学或化学试剂法加速溶蚀能有效缩短试验周期;细微观试验方法如计算机断层成像技术、电镜扫描技术、X射线衍射技术的联合使用是研究水泥基材料溶蚀机理的有效手段;水灰比和水质是影响溶蚀进程的最主要因素;水泥基材料的接触溶蚀是其内部氢氧化钙和水化硅酸钙等成分依次溶解并在浓度梯度作用下的扩散过程。针对水工混凝土常在较高水力梯度下工作的特点,认为复杂因素作用下水工混凝土渗透溶蚀机理、渗透溶蚀劣化模型以及裂缝条件下的溶蚀劣化混凝土面板损伤开裂-裂缝扩展等问题有待进一步研究。

Advances in cement-based materials leaching test

Concrete leaching experimental investigations, main influence factors during the leaching process and the leaching mechanisms are concisely reviewed, analyzed and discussed. The results show that contact leaching and penetration leaching are two major macroscopic leaching test methods. Leaching speed can be accelerated by electrochemistry or chemical reagent method and the test period can be effectively shortened. The combined utilization of the microscopic experimental methods such as CT, SEM and XRD is an effective way to investigate the leaching mechanisms for cement-based materials. Water cement ratio and water quality are the main factors of the leaching process. The concrete contact leaching is a process caused by the successive dissolution of CH, C-S-H and other compounds, with the diffusion induced by the concentration gradient. Considering the high hydraulic gradient working conditions of hydraulic structures, leaching mechanisms of hydraulic concrete under multi-factors, penetration leached hydraulic concrete models, and the cracking-fracture propagation problems of penetration leached concrete face slabs under cracking conditions need further investigation.