干湿循环下硫酸盐对水泥基孔隙材料的侵蚀破坏综述

Review on the Sulfate Attack of Cement-Based Porous Materials under Drying-Wetting Cycles

硫酸盐对水泥基孔隙材料的侵蚀破坏是影响其耐久性的主要因素之一。相较于完全浸泡在硫酸盐溶液中,水泥基孔隙材料在干湿循环作用下其破坏更严重且破坏机理更复杂。过去的几十年内,学者们主要将研究重点放在硫酸盐化学侵蚀上,对干湿循环作用下水泥基孔隙材料的硫酸盐物理侵蚀破坏研究较少。处于硫酸盐环境中的水泥基孔隙材料主要遭受硫酸盐结晶物理侵蚀、化学侵蚀和干湿循环三重作用,而水泥基孔隙材料遭受硫酸盐结晶破坏的机理研究一直是个难点。综合分析了国内外学者对干湿循环下,水泥基孔隙材料硫酸盐结晶侵蚀破坏的机理和微-宏观试验现象,以及影响侵蚀的主要因素:硫酸根离子浓度、温度和相对湿度的等的影响;并从微观机理方面对水泥基材料力学性能和力学行为方面进行总结分析。最后,对干湿循环作用下水泥基孔隙材料遭受硫酸盐结晶侵蚀破坏的研究进行若干展望。

The erosion of cement-based porous materials by sulfate attack is one of the main factors affecting its durability.Compared with fully immersing in sulfate solution,deterioration of the cement-based porous materials subjected to drying-wetting cycles and sulfate will be more severe,and its damage mechanism is more complicated.In past decades,many researchers have paid special attention to chemical sulfate attack.Scarce work on the deterioration mechanism of cement-based porous materials subjected to drying-wetting cycles and physical sulfate attack has been carried out.The cement-based porous materials are subjected to triple actions of physical sulfate attack,chemical sulfate attack and drying-wetting cycles.The deterioration mechanism of cement-based porous materials subjected to physical sulfate attack remains to be a difficult question.This work summarizes studies from scholars at home and abroad on deterioration mechanisms and micro-macro experimental results of the cement-based porous materials,which are subjected to dual actions of drying-wetting cycles and physical sulfate attack,mainly influencing factors such as sulfate concentration,temperature and relative humidity are summarized.Moreover,based on the micro-mechanism,the mechanical properties and behaviors of cement-based porous materials are also reviewed in this work;last but not least,several perspectives on the physical sulfate attack of cement-based porous materials are also presented.