复合因素作用下混凝土硫酸盐侵蚀劣化机理

Deterioration Mechanisms of Sulfate Attack on Concrete under the Action of Compound Factors

摘要:

通过微观和宏观观测,综合揭示了单独硫酸钠溶液侵蚀、亚高温水淬循环和硫酸钠溶液侵蚀交替进行、碳化和硫酸钠溶液侵蚀交替进行3种工况下混凝土受侵蚀劣化规律.研究结果表明:3种工况的主要侵蚀产物均为钙矾石,没有明显检测到石膏和碳硫硅钙石;与单独硫酸钠溶液侵蚀相比,亚高温水淬循环作用加剧了硫酸根离子向混凝土内部的扩散传输,从而造成其强度的显著劣化;碳化层的存在在一定程度上减轻了硫酸根离子的扩散传输,但碳化和硫酸钠溶液侵蚀的交替作用仍导致了混凝土抗压强度下降.

Abstract:

By micro-and macro-observations,the deterioration mechanisms of concrete under three cases such as single sodium sulfate solution attack,alternant action of repeat sub-high temperature/cooling by water and sodium sulfate solution attack,alternant action of carbonation and sodium sulfate solution attack are revealed.Micro-observations include the analysis of attacking products by thermal analysis method and the determination of sulfate-ion content by modified barium sulfate gravimetric method.Macro-observati...