硫酸盐和氯盐侵蚀后钢筋混凝土梁的抗剪性能

SHEAR PERFORMANCE OF REINFORCE CONCRETE BEAMS CORRODED BY SULFATE SALT AND CHLORIDE

采用干湿循环方法对试验梁进行硫酸盐和氯盐的加速侵蚀,研究不同腐蚀度和锈蚀率时试验梁的破坏形态、开裂情况、抗剪承载力的退化规律。试验结果表明:当腐蚀试验梁受力荷载超过一定的限值,P-w曲线立即笔直地向上发展,斜裂缝的发展较未腐蚀试验梁突然和迅速。随着腐蚀程度的增大,试验梁斜裂缝的开裂越来越晚。λ=2.22时,相对剪切开裂荷载由增到减的拐点为1.914;λ=1.39时,拐点为2.335。试验梁的极限剪切荷载,经历先增后降的阶段。λ=2.22时,极限剪切荷载增长率达到27.92%;λ=1.39时,极限剪切荷载增长率则达到34.47%。在试验数据的基础上建立了试验梁抗剪性能的退化计算模型,为结构设计及结构加固提供参数。

The reinforced concrete beams corfoded rapidly by sulfate salt and chloride through tile accelerated corrosion method, the destruction shape, ductility, shear carrying capacity of the beams were studied under different corrosion degree. It can be seen that from the experimental results, when the test load of corroded beams reach the ultimate load, the P-w course became steep. The shear cracking time of test beams were more and more latter. When λ=2.22, the point where the compared shear cracking load from increase to decrease was 1. 914, and when λ= 1.39, the point was 2. 335. The shear bearing capacity of the beams first increase then drop with the corrosion degrees increase, when λ= 2.22, the increase ratio of the ultimate load reach 27.92 percent, and which was 34.47 percent when λ= 1.39. Based on the experimental results analysis, the prediction models for cracking load and ultimate load and ductility of the corroded beams with different corroded degree were founded. Which provided reliable basis for structural design and structure reinforcement.