人工气候与恒电流通电法加速锈蚀钢筋混凝土梁的结构性能比较研究

采用人工气候环境和恒电流通电法对钢筋混凝土梁进行加速锈蚀试验,以钢筋混凝土梁底顺筋锈胀裂缝宽度为标准,对钢筋表面锈蚀特征、锈蚀钢筋力学性能、以及锈蚀钢筋混凝土梁的结构性能进行了试验研究与比较分析。由于人工气候环境与恒电流通电法使混凝土内钢筋锈蚀的电化学机理不同,试验结果表明:在混凝土表面顺筋锈胀开裂宽度相同条件下,两种环境引起的钢筋表面锈蚀特征、锈蚀钢筋名义强度和延伸率、锈蚀钢筋混凝土梁承载能力与延性均有明显的差异。人工气候环境模拟自然环境气候过程,并强化了气候因素的老化作用,使混凝土内钢筋锈蚀具有相同的电化学机理,并达到加速锈蚀的目的,将对进一步研究钢筋锈蚀程度对结构性能退化影响具有重要的学术和实际意义。

A comparative study on structural behavior of deteriorated reinforced concrete beam under two different environments

Two groups of reinforced concrete beam were tested with accelerated deterioration using a galvanostatic method and under artificial climate environment,respectively.The structural behaviors of deteriorated concrete beams,including its surface characteristic and mechaniccal behavior of corroded bars,capacity and durability of deteriorated beams were compared between the two accelerated test methods based on the same width of corrosion crack.The test results showed obvious differences in structural deterioration when using the galvanostatic method and artificial climate environment with the same width of corrosion crack.This is largely due to different corrosion mechanisms of concrete beams under the conditions of galvanostatic method and artificial climate.The environment under artificial climate can obviously simulate the natural climatic processes,thus strengthen the ageing function.Therefore,the same corrosion mechanism under artificial and natural climate environments and accelerated deterioration can be achieved.