硫酸盐腐蚀与冻融共同作用下井壁混凝土损伤劣化研究  

Research on Damage and Deterioration of Concrete for Shaft Lining Under Action of Sulfate Corrosion and Freeze-thaw

作　　者：赵力[1] 宋少民[2] 刘娟红[1] 纪洪广[1] 

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]北京建筑大学北京节能减排关键技术协同创新中心,北京100044

出　　处：《煤矿安全》2017年第7期57-61,共5页Safety in Coal Mines

基　　金：国家重点研发计划资助项目(2016YFC0600800);国家自然科学基金资助项目(51374036)

摘　　要：通过试验研究了初始损伤井壁混凝土随硫酸盐腐蚀和冻融循环次数的增加,其质量、超声波传播速度及强度等的变化,运用损伤力学对损伤进行定量评价和参数拟合并借助环境扫描电镜观测分析混凝土微结构的变化。试验结果表明,随着腐蚀和冻融周期循环次数的增加,混凝土的质量呈先增大后迅速减小,超声波传播速度和抗压强度逐渐减小,初始损伤加剧了混凝土性能的劣化;冻融在混凝土损伤劣化中起主导作用,其引起的破坏作用远大于硫酸盐腐蚀。在冻融因素作用下,初始损伤对混凝土性能劣化的影响明显增强;腐蚀和冻融的叠加作用引起混凝土内部微裂纹的产生和连通,而初始损伤的存在使得微裂纹网络体系更加发达,呈现龟裂状延伸和扩展。With the increase of corrosion and freeze-thaw cycles, the changes in the parameters of concrete with initial damage were experimentally studied, including mass, ultrasonic velocity and compressive strength. The quantitative evaluation and parameter fitting was made based on damage mechanical theory. The changes of concrete microstructures were analyzed using the environmental scanning electron microscopy（ESEM）. The research results show that： with the increase of corrosion and freeze-thaw cycles, the mass of concrete increases first and then decreases, and ultrasonic velocity and compressive strength of concrete gradually is reduced.The initial damage exacerbates deterioration of concrete. The action of freeze-thaw plays a leading role in the damage and deterioration of concrete and brings the more and greater destructive effect than corrosion. Under the action of freeze-thaw, the initial damage has an more obvious impact on deterioration of concrete. The action of sulfate attack and freeze-thaw leads to the formation and connection of micro-cracks inside concrete. The existence of initial damage leads to more developed micro-cracks network which extends and expands continuously.

关 键 词：初始损伤 硫酸盐腐蚀 冻融损伤 损伤演化 微观结构 混凝土 井壁 

分 类 号：TD262[矿业工程—矿井建设]