钢筋混凝土结构锈胀开裂宽度的试验研究及预测模型

设计了45片钢筋混凝土(RC)构件,基于RC构件通电加速锈蚀,对该批构件进行腐蚀试验研究,测试了锈胀裂缝宽度及其位置和发生时间。以钢筋锈蚀率、保护层锈胀开裂、锈胀裂缝宽度、相对保护层厚度和混凝土强度为分析参数,结合测试数据,利用加速腐蚀和自然腐蚀的对应关系,通过数理统计回归分析建立了锈胀开裂宽度的预测模型。分析了各参数对锈胀开裂扩展的影响。该模型对RC结构耐久性设计提供一定的参考。使用本文建立的模型以及规范模型对文献试验数据和一座服役近40年的实桥构件的锈蚀率和锈胀裂缝宽度进行了预测,计算结果表明本文模型有较强的适用性,能够用于实桥锈胀损伤分析。

Experimental Study and Prediction Model of Corrosion-Induced Crack width in RC Structure

45 reinforced concrete (RC) construction members were designed and used for experimental study of corrosion based on RC member energized accelerated corrosion. The corrosion crack width, crack location and occurrence time of specimens were measured. Taking the corrosion rate of reinforced concrete, the corrosion-induced cracking of protective layer, the crack width, the relative thickness of protective layer (c/d) and the concrete strength as parameters of analysis, combining with test data, using the corresponding relation between accelerated corrosion and natural corrosion, a prediction model for corrosion-induced crack width was established based on regression analysis of mathematical statistics. The influence of each parameter on corrosion crack propagation was analyzed. This model provides a reference for durability design of RC structure. Combining above-mentioned model with canonical model, experimental data published in literatures and the corrosion rate and corrosion-induced crack width of a real bridge already served for nearly 40 years old were predicted. Results show that the model proposed in this paper has good relevance and consistency and has prospective applicability for predicting corrosion-induced crack width of real bridge.