中文摘要：

通过实验室加速腐蚀方式和三点弯曲试验研究酸雨腐蚀对混凝土断裂韧度的影响,得到在酸雨腐蚀条件下混凝土裂尖的劣化样貌以及断裂韧度的劣化情况。在模拟酸环境下,腐蚀深度随着浸泡时间的延长而增加,混凝土裂尖腐蚀层材料发生物理化学变化,并随着腐蚀时间的延长而变得松弛并产生微裂隙,导致混凝土裂纹尖端抵抗开裂的能力降低。三点弯曲试验结果表明：相比未腐蚀试件,腐蚀试件断裂韧度发生了明显改变,并且随腐蚀时间呈现出先增加后减小的趋势。断裂韧度的劣化过程受p H值的影响,溶液p H值越小,则腐蚀初期的性能强化时间越短,断裂韧度劣化越快。腐蚀层混凝土材料的劣化是导致混凝土力学性能下降的主要因素,通过试验得到了腐蚀混凝土断裂韧度和腐蚀深度间的关系曲线。

英文摘要：

The deterioration of fracture toughness of concrete caused by acid rain attack was investigated through laboratory-accelerated corrosion tests and three-point bending tests. Fracture toughness of the corroded specimens with different corrosion degrees were obtained in the study. Under simulated acid environment,the corrosion depth increased with corrosion duration. The observation by scanning electron microscopy showed that the microstructures of crack tip were porous and loose due to acid corrosion,and many crisscross cracks appeared at corrosion layer,which made the corresponding resistance stress to crack propagation decreased. The experimental results of three-point bending tests showed that fracture toughness of the corroded specimens increased in the initial stage of immersion,and decreased with increasing immersion time. The lower the p H value was,the shorter the duration of the strengthening phase was. Under the impact of acid corrosion,the concrete material physical and chemical properties changed significantly around the crack tip,which was the main factor resulting in decrease of the mechanical properties of concrete. The relationship curves of fracture toughness and corrosion depth were obtained in the study.