水泥基矽土注浆材料抗海水侵蚀性能研究∗

为研究水泥基矽土注浆材料抗海水侵蚀性能,根据对工程现场附近海域的海水水化学分析结果配制人工海水溶液,以此对注浆结石体浸泡养护,通过对不同龄期的结石体试件开展抗压强度、L?NMR、XRD、FT?IR 和 SEM 等测试揭示了其在不同侵蚀龄期下的抗侵蚀性能变化规律。研究结果表明：随侵蚀龄期上升,材料抗蚀能力先增大后减小,侵蚀前期由于侵蚀产物“填充效应”和侵蚀离子的“盐激发”效应优化了结石体孔径分布,7 d 时抗蚀系数 K 最大,0.7、1.0 和 1.5 水灰比对应抗蚀系数分别为 1.26、1.23 和 1.18,后逐渐下降;60 d 后 AFt 和 Friedel 盐等侵蚀产物破坏了硬化浆体结构,小孔转变为大孔,导致抗蚀系数 K 小于 1.0,水灰比 1.5 时,180 d 对应 K 值仅为 0.45,在相同的侵蚀条件下,不同的水灰比表现出的抗蚀性有所差异,水灰比越小,抗蚀性越强,因此在滨海区域使用 CIS 进行注浆时,应在保证浆液可注性的同时尽量降低水灰比。

Study on Seawater Erosion Resistance of Cement‑Based Silica Grouting Material

To study the seawater erosion resistance of cement-based silica grouting material, an artificial seawater solution was prepared based on the hydrochemical analysis of seawater near the project site. The solution was used to immerse and cure the grouted stone samples. Tests on compressive strength, L-NMR, XRD, FT-IR, and FT-IR, and SEM, were conducted on specimens at different ages to reveal the changes in erosion resistance over time. The results indicate that the corrosion resistance of the material initially increased and then decreased with prolonged exposure. In the early stages of erosion, the "filling effect" of erosion products and the "salt excitation" effect of erosion ions optimized the pore size distribution of the grouted stone, with the maximum erosion resistance K observed at 7 days. The K values for water-cement ratios of 0.7, 1.0 and 1.5 were 1.26, 1.23 and 1.18, respectively, before gradually decreasing. After 60 days, erosion products like Aft and Friedel''s salt compromised the hardened grout structure, causing small pores to transform into larger ones, resulting in a K value less than 1.0. At a water-cement ratio of 1.5, the K value at 180 days was only 0.45. Under the same erosion conditions, the erosion resistance varied with different water-cement ratios, with lower ratios exhibiting stronger resistance. Therefore, when CIS is used for grouting in coastal regions, it is recommended to minimize the water-cement ratio while ensuring the injectability of the grout.