地下结构混凝土渗透特性试验研究

Experimental research on concrete permeability of underground structure

根据地下结构承受水压及构件存在裂缝的情况,采用自制混凝土试块模具、自制可控开裂混凝土装置、自制可控压力水头装置、裂缝测宽仪组成的试验系统,在不同水压、氯离子浓度、裂缝宽度以及浸泡时间等工况下进行了开裂混凝土渗透特性试验。试验结果表明:当其他试验条件相同时,压力水头下与自然浸泡状态下的氯离子运移规律有明显的差异,压力水头作用下混凝土各层自由氯离子含量均有明显的提高;存在控制氯离子浸泡溶液运移的裂缝宽度阈值,且该阈值不受水头压力大小的影响。该试验方法可作为同类研究的借鉴和参考。

In accordance with bearing water pressure and cracking, using test system made up by self-made concrete sample mould, self-made controlled cracking device, self-made controlled water pressure device, and crack width measuring instrument, experiments for permeability of cracked concrete are carried out under the conditions of different water pressures, concentrations of chloride ion, crack widths and soaking times. The experiment results show that chloride ion content of concrete increases significantly with the increasing of water pressure when the other experimental conditions are same; and the migration laws are different; and crack width threshold which is independent of water pressure controls the migration of chloride ion. This method can provide a reference for similar study.