聚丙烯纤维混凝土在腐蚀-疲劳耦合作用下耐久性性能试验分析

Experimental analysis on durability of polypropylene fiber reinforced concrete under corrosion fatigue coupling

为分析混凝土在腐蚀-疲劳耦合环境下的耐久性性能。建立了腐蚀疲劳耦合试验方案,即先将混凝土试块进行疲劳试验,然后放在配制好的腐蚀环境中(5%的HCl溶液和5%的Na2SO4溶液)浸泡,分析不同应力水平和浸泡时间对混凝土耐久性性能的影响。为了改进普通混凝土在腐蚀-疲劳环境下的耐久性性能,还在混凝土中掺入不同含量的聚丙烯纤维,分析纤维含量对混凝土抗腐蚀-疲劳耦合的性能。通过试验得出:(1)随着纤维掺量的增加,混凝土的抗氯离子侵蚀和抗硫酸根离子侵蚀的能力增加,最佳掺量为1.5%;(2)随着腐蚀环境的浸泡时间增加,混凝土的抗氯离子侵蚀和抗硫酸根离子侵蚀的能力便减弱;(3)在腐蚀-疲劳耦合试验中,随着应力水平和循环次数的增加,混凝土的耐久性性能迅速下降。

In order to analyze the durability of concrete in corrosion fatigue coupling environment.The corrosion fatigue coupling test scheme is established,that is,the concrete blocks are first tested for fatigue,and then soaked in the configured corrosion environment(5%HCl solution and 5%Na2SO4 solution).The effects of different stress levels and soaking time on the durability of concrete are analyzed.In order to improve the durability of ordinary concrete in corrosion fatigue environment,polypropylene fiber with different content is added into concrete to analyze the effect of fiber content on the corrosion fatigue coupling performance of concrete.The results show that(1)With the increase of fiber content,the ability of concrete to resist chloride ion erosion and sulfate ion erosion increases,and the optimal content is 1.5%.(2)With the increase of immersion time in corrosive environment,the ability of concrete to resist chloride ion erosion and sulfate ion erosion decreases.(3)In the corrosion fatigue coupling test,with the increase of stress level and cycle time,the ability of concrete to resist chloride ion erosion and sulfate ion erosion decreases.With the increase of the number of rings,the durability of concrete decreases rapidly.