高浓度氯盐环境下钢筋混凝土裂缝扩展影响因素及规律研究

Study on influencing factors and laws of crack propagation in reinforced concrete under high concentration chloride environment

为研究高浓度氯盐环境下钢筋混凝土保护层首次出现裂缝的时间和裂缝宽度扩展规律,采用直流电加速锈蚀法,研究不同电流密度、氯盐浓度、保护层厚度、钢筋直径以及水胶比等因素的影响,探究混凝土裂缝的扩展因素及裂缝扩展规律。结果表明:随电流密度、氯盐浓度、水胶比、钢筋直径增加,锈胀裂缝宽度扩展速度加快;随保护层厚度加厚,锈胀裂缝宽度扩展速度越慢。其中保护层厚度对混凝土裂缝首次开裂的影响最为显著,电流密度和钢筋直径影响次之,氯盐浓度和水胶比的影响相对较小。

In order to study the first crack time and crack width propagation law of reinforced concrete protective layer in high concentration chloride environment,the DC accelerated corrosion method is used to study the effects of different current density,chloride concentration,protective layer thickness,steel bar diameter and water-binder ratio on the crack propagation factors and crack propagation law of concrete.The results show that with the increase of current density,chloride concentration,water-binder ratio and steel bar diameter,the propagation speed of rust expansion crack width increases.With the increase of the thickness of the protective layer,the propagation speed of the rust expansion crack width is slower.Among them,the protective layer thickness has the most significant effect on the first cracking of concrete cracks,followed by the current density and steel bar diameter,and the influence of chloride concentration and water-binder ratio is relatively small.