受“渗流-应力场”及SO_4^(2-)-Cl^-作用后高性能混凝土性能研究

Study of Mechanical Properties of High-performance Concrete under Action of Seepage-Stress Fields and SO_4^(2-)-Cl^-

为揭示地下高性能混凝土性能劣化规律,针对地下结构中高性能混凝土所处环境特点,通过试验模拟"渗流-应力场"及硫酸盐、氯盐的共同作用,检测腐蚀后混凝土的承载力并分析腐蚀后混凝土中的腐蚀产物。结果表明:1)荷载单独变化时,荷载越大混凝土腐蚀越明显;2)水压单独变化时,水头差越大混凝土腐蚀程度越严重;3)水头差对混凝土抗压性能的影响要高于荷载,但荷载和水头差越大,两者差距将逐渐缩小;4)荷载和水头差同时作用下的混凝土受侵蚀情况更加严重,两者共同作用比单一因素作用后混凝土承载力减少更多。微观测试和分析表明,荷载和水头差作用会加快混凝土内腐蚀产物的生成,水头差对混凝土抗压性能的影响要略高于荷载,与混凝土强度测试分析结果一致。

The seepage-stress field and the interaction of sulfate and chloride salts on high-performance concrete of underground structure are simulated by experiment to reveal the degradation rules of underground high-performance concrete ; and the compressive strength of the concrete after corrosion is detected and the corrosion products in the corroded concrete are analyzed. The results show that： 1） When the load varies independently,the larger the load is, the more obvious the erosion is. 2） When the water pressure varies independently,the greater the waterhead difference is,the more serious the corrosion is. 3） The effect of the waterhead difference on concrete compressive strength is higher than that of load; but with the increase of the waterhead and load,the effect of them becomes almost the same. 4） Compares to single factor,the concrete compressive strength decreases more under two combined action; the concrete corrosion situation will be more serious under the combined action of load and waterhead difference. The micro test andanalysis show that the load and waterhead difference will fasten the formation of corrosion products in concrete; the test result of effect of waterhead difference on concrete compressive properties is the same with analytical one.