荷载-硫酸腐蚀耦合下混凝土物理力学性质劣化特性

Deterioration of Concrete Under Combined Load and Sulfuric Acid Corrosion

摘要:

开展不同荷载?硫酸腐蚀耦合实验，并考虑荷载作用建立了通用离子扩散模型用以刻画固相钙的溶蚀过程，探究了不同荷载条件下混凝土受硫酸腐蚀劣化过程。结果表明，硫酸腐蚀过程受离子扩散与固相钙溶解的共同控制，腐蚀速率逐渐降低；数值模拟结果与试验高度一致，验证了其可靠性；荷载对混凝土的影响包括孔隙收缩和损伤累积，小荷载可抑制腐蚀，而大荷载会加速腐蚀；在相同荷载水平下，交变荷载下的腐蚀速率高于恒定荷载，且随交变周期增加而略有减缓；钢纤维对硫酸扩散起阻滞作用，有助于降低混凝土的腐蚀程度并减缓腐蚀速率。

Abstract:

This paper first conducted experiments under different load-sulfuric acid corrosion coupling conditions. A general ion diffusion model was established to describe the dissolution process of solid-phase calcium， considering the effect of load， and the deterioration of concrete under sulfuric acid corrosion at different load levels was investigated. The results indicate that sulfuric acid corrosion is jointly controlled by ion diffusion and solid-phase calcium dissolution， with the corrosion rate gradually decreasing over time. Numerical simulation results closely match experimental data， confirming their reliability. Loading affects concrete through pore shrinkage and damage accumulation： low loads can inhibit corrosion， whereas high loads accelerate it. At the same loading level， corrosion under cyclic loading is higher than that under static loading， though it slightly decreases with increasing loading cycles. Steel fibers act as a barrier to sulfuric acid diffusion， reducing corrosion and slowing its rate. These findings provide a reference for the durability design and maintenance of deep tunnel structures.