酸雨侵蚀弯曲型破坏钢筋混凝土柱抗震性能试验研究

Experimental research on seismic behaviors of corroded reinforced concrete column failed in bending subjected to acid rain exposure

为研究酸雨侵蚀后钢筋混凝土(RC)柱抗震性能的演化规律,对4榀剪跨比为5的RC柱试件(C-1,C-2,C-3和C-4)进行酸雨环境模拟试验,观察腐蚀后各试件的外观损伤状况;通过拟静力试验,分析酸雨侵蚀对试件滞回性能、承载能力、延性、刚度以及耗能性能等的影响。研究结果表明:酸雨侵蚀对RC柱的外观损伤状况及抗震性能均有显著影响,随着腐蚀程度增加,试件表面出现孔洞,棱角处混凝土疏松,损伤逐渐加剧;在加载过程中,受力裂缝发展速率加快,范围增大;结束加载时,试件破损程度更加严重,试件滞回环的丰满程度明显降低,承载能力、延性以及耗能性能显著下降,强度衰减和刚度退化速率随之加快,以腐蚀程度最严重的试件C-4为例,其峰值荷载、位移延性系数、累积耗能相比未腐蚀试件C-1分别降低17.84%,12.33%和24.82%。

In order to study the seismic behavior of reinforced concrete(RC) columns subjected to acid rain exposure, simulated acid rain tests were applied to four RC column specimens with a shear span ratio of 5. Then,quasi-static tests were performed on the specimens. The surface damage of the specimens was observed. The influence of acid rain exposure on hysteretic behavior, bearing capacity, ductility, stiffness, and energy dissipation of the specimens was analyzed. The results show that acid rain exposure has significant effect on the appearance damage and seismic behavior of the specimens. Holes and loosened concrete can be observed on the surface of the corroded specimens. As the level of corrosion increases, cracks of the specimens are extended quickly, and the damage degree becomes more serious at the end of the tests. Also, the higher the corrosion level, the lower the fullness of the hysteretic loop of the specimens, the worse the bearing capacity, ductility, and energy dissipation.For example, the peak load, displacement ductility coefficient and cumulative energy consumption of the specimen C-4 with the most serious corrosion level are 17.84%, 12.33% and 24.82% lower than those of the non-corroded specimen C-1, respectively.