（大连理工大学海岸和近海工程国家重点实验室， 大连 116024）

［摘要］通过四点弯曲试验，研究并分析了在干湿循环和持续荷载共同作用下CFRP加固高强混凝土梁的耐久性。干湿循环介质采用3-5%的NaCl溶液，循环次数设置0次、40次、80次和120次，持载等级为未加固钢筋混凝土梁极限荷载的0%，30%和60%。试验结果表明：干湿循环和持载作用后，加固梁的性能发生劣化，破坏方式逐渐由混凝土表层破坏向胶层与混凝土之间的粘结破坏发展；加固梁的极限荷载、跨中极限挠度、CFRP极限应变整体呈下降趋势，后期刚度显著降低，且随着持载等级提高，退化程度进一步加剧。

［关键词］高强混凝土； CFRP； 干湿循环； 持续荷载

中图分类号：TU375文献标识码：A文章编号：1002-848X(2017)21-0078-06

Durability study of high strength concrete beams strengthened with CFRP under sustained load and dry-wet cycle conditions

Wang Suyan, Ding Li, Hong Lei, Song Zelin

(State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China)

Abstract:Through the four-point bending test, the durability of CFRP reinforced concrete beams under the combined conditions of dry-wet cycles and sustained load was studied and analyzed. The dry-wet cycle medium adopted 3-5% NaCl solution, and the cycle times were set as 0, 40, 80 and 120 times, and the sustained loading grades were 0%, 30% and 60% of the ultimate load of the unreinforced concrete beam. Experimental results show that the performances of the strengthened beams are deteriorated after dry-wet cycles and sustained load, and the failure mode gradually develops from the damage of concrete surface to the bonding between adhesive layer and concrete; ultimate load, ultimate deflection at mid-span and ultimate strain of CFRP overall show a downward trend, and the rigidity in later stage decreases significantly, and the degradation degree further aggravates with the increase of sustained load level.

Keywords:high strength concrete; Carbon Fiber Reinforced Polymer(CFRP); dry-wet cycle; sustained load

*国家自然科学基金项目（51378089）。

作者简介：王苏岩，本科，教授，硕士生导师， Email: suyanw@dlut.edu.cn。