复杂环境下CFRP加固高强混凝土梁力学性能研究  

Research on Mechanical Behavior of High Strength Concrete Beams Strengthened with CFRP under Complex Environmental Conditions

作　　者：王苏岩[1] 刘振杰 张红涛 朱方芳 WANG Suyan;LIU Zhenjie;ZHANG Hongtao;ZHU Fangfang(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian,China,116024)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《沈阳建筑大学学报（自然科学版）》2018年第4期577-585,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51378089)

摘　　要：目的研究持续荷载、冻融循环、干湿交替共同作用下碳纤维增强复合材料(CFRP)加固高强混凝土梁的抗弯性能和退化规律.方法利用自制的持载设备给加固梁施加持续荷载并经过冻融和干湿腐蚀后,通过四点弯曲破坏试验分析持载等级、冻融次数及干湿次数对试验梁耐久性的影响.结果相较于参照梁,环境作用后的试件的开裂荷载与剥离荷载都有了不同程度的下降.冻融、干湿耦合条件下的试验梁的承载性能弱于只有持续荷载作用时的试验梁,持载、冻融、干湿共同作用时梁的剥离荷载变得更低.经过长时间的复杂环境作用,试验梁的极限挠度变化规律不明显,发生剥离时对应的挠度逐渐减小.结论冻融与干湿耦合作用下,试验梁的力学性能发生了退化,持续荷载的存在进一步加剧了试验梁的损伤程度.This paper mainly studies the flexural performance and deterioration lawof CFRP-high strength reinforced concrete beams under coupling effect of sustained loading,freeze-thawcycling and dry-wet cycling. After being applied the sustained loading by the home-made device and successively subjected to freeze-thawcycling and dry-wet cycling,the specimens are tested by fourpoint bending method to analyze the effects of loading level,the number of freeze-thawcycling and the number of dry-wet cycling on the durability of reinforced beams. Both cracking loads and debonding loads of specimens under different environment degrade to different extents compared with the control specimen. The flexural performance of test beams under coupling effect of freeze-thawcycling and dry-wet cycling is lower than that of the test beams only under sustained loading.In addition,the debonding load of specimens is much lower under coupling effect of freeze-thawand dry-wet environmental conditions as well as sustained loading. After a long time exposure in experiment environment,the change of the ultimate deflection of beams is not significant whereas the deflection at the initial stage of debonding decreases gradually. Results indicate that the mechanical properties of test beams has degraded under the freeze-thawand dry-wet coupling environment,while the presence of sustain loading further reduces bending capacity of test beams.

关 键 词：CFRP 冻融循环 干湿交替 持续荷载 钢筋混凝土梁 高强混凝土 耐久性 

分 类 号：TU375.1[建筑科学—结构工程]