钢筋混凝土结构锈蚀损伤的解析解

Analytical solution for corrosion damage of reinforced concrete structures

分析了钢筋混凝土结构由于钢筋锈蚀所引发的损伤全过程。假设钢筋周围铁锈层厚相等并考虑混凝土的软化特性,提出了混凝土保护层锈蚀损伤模型,该模型将混凝土保护层的损伤全过程分为弹性变形和部分开裂两个阶段,通过建立和求解各阶段的微分方程,给出了每一时刻混凝土保护层中各点的位移和应力。基于这些解析解,获得了初裂时间、完全开裂时间和每一时刻的锈胀力。对不同的保护层厚度和锈蚀率将本文解析解与实验结果进行了比较,从而证实了本文解的有效性。最后,对计算结果进行了详细的讨论。

The damage of reinforced concrete structures due to reinforcement corrosion is analyzed. Assuming the corrosion layer on steel bar surface is uniform and taking the softening characteristics of concrete into account the corrosion damage model for concrete cover is developed. In the model, the damage process of the concrete cover is divided into two distinct phases:elastic deformation and partial cracking. By establishing and solving the differential equation corresponding to each phase the displacement and stress at arbitrary point in concrete cover and at arbitrary instant are obtained. Based on this analytical solution, the instant of initial cracking, the instant of complete cracking and the corrosion-induced expansive force are deduced. The validity of this solution is verified by experimental data.