混凝土设计参数对氯盐环境下钢筋锈蚀的影响研究

研究了混凝土设计参数包括水胶比、胶凝材料组成、保护层厚度和混凝土氯离子含量等对氯盐环境下混凝土中钢筋锈蚀的影响。通过模拟氯盐环境下混凝土中钢筋所处的锈蚀环境,并以一定的方法加速混凝土中钢筋的锈蚀,采用电化学测试手段(钢筋腐蚀电位和钢筋腐蚀电流密度)来评价各设计参数对钢筋锈蚀的影响。结果表明,水胶比越小、保护层厚度越大、混凝土氯离子含量越小、使用矿物掺合料能有效延缓钢筋开始锈蚀时间,并在不同程度上减小钢筋的锈蚀速率。试件在试验一段时间后被破损,将钢筋周围砂浆制样并进行SEM扫描电镜元素分析试验,进一步验证电化学测试方法的准确性及钢筋的锈蚀程度。

Research of the Influence of Concrete Designed Value to Corrosion of the Steel Bar under Chloride Environment

The influence of designed parameters including W/B ratio,composition of binding materials,depth of concrete cover and chloride ion content in concrete on corrosion of the steel bar in concrete was studied.Simulation tests are made in chloride environment,by accelerating the corrosive rate of the steel bar in concrete specimen.Electrochemical method(half-cell potential and corrosion current density) are used to evaluate the experimental result.It is found that to decrease the W/B ratio,increase the depth of concrete cover,lower the chloride ion content in concrete and use mineral binding materials,the initiation time of steel bar corrosion in concrete can be delayed and the corrosion rate can be decreased to certain extent.Concrete specimen are crashed during the experiment and the mortar beside the steel bar are taken out to make samples for SEM testing to venify the rationality of electrochemical method and the real corrosion extent.