焙烧Mg-Al水滑石水泥浆涂层对钢筋氯离子腐蚀的缓蚀性能

本工作研究了焙烧Mg-Al水滑石(LDO)水泥浆涂层对钢筋氯离子腐蚀的缓蚀性能。将焙烧Mg-Al水滑石材料添加到水泥浆中制备了复合水泥浆涂层,并涂覆在钢筋表面。由等温吸附实验、线性极化测试(LP)、电化学阻抗谱测试(EIS)研究了在混凝土模拟孔溶液中复合水泥浆涂层对钢筋氯离子腐蚀的缓蚀性能；此外,采用X射线衍射仪(XRD)和傅里叶变换红外光谱(FT-IR)检测了吸附实验前后水泥浆的物相变化,探讨了焙烧Mg-Al水滑石水泥浆涂层对钢筋氯离子腐蚀的缓蚀机理。结果表明,LDO的掺入能显著提高水泥浆体对氯离子的饱和吸附量,且随着LDO掺量的增加,复合水泥浆涂层的综合阻锈效果增强。复合LDO涂层缓释机理归因于层状结构的复原使其能有效地吸附氯离子并释放氢氧根离子,从而能有效阻止氯离子的侵蚀。

Protecting of Steel from Chloride-induced Corrosion by Cement Slurry Coatings with Calcined Mg-Al Layered Double Hydroxides

This study explored the protection of steel from chloride-induced corrosion by cement slurry coatings with calcined Mg-Al layered double hydroxides. The calcined Mg-Al hydrotalcite material was added to the cement slurry to prepare a composite cement slurry coating on the steel bar surface. The corrosion inhibition performance of composite cement slurry coatings on chloride ion corrosion in concrete simulated pore solution was studied by the isothermal adsorption experiment, linear polarization test (LP) and electrochemical impedance spectroscopy (EIS). In addition, the phase change of the cement slurry before and after the adsorption experiment was observed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results showed that the incorporation of LDO could significantly increase the saturated adsorption capacity of cement slurry, and with the increase of LDO content, the comprehensive effect of composite cement slurry coatings from chloride-induced was enhanced. LDO composite coatings controlled-release mechanism attributed to the recovery of lamellar mechanism could effectively adsorb chloride ions and release hydroxyl ions, which could effectively prevent the erosion of chloride ions.