RESEARCH ON FREEZE-THAW RESISTANCE BEHAVIOR OF BONDED JOINTS BETWEEN CFRP AND HIGH STRENGTH CONCRETE UNDER SUSTAINED LOAD

摘要

In recent years, increasing attention is focused on the bond degradation for strengthened normal concrete specimens that are aged in varied environments, but less attention to the durability of high strength concrete strengthened with CFRP sheets. In cold regions, the main factor limiting the application of FRP strengthening concrete structures is frost environment. The freeze-thaw resistance behavior of bonded joints between CFRP and high strength concrete under sustained load are studied according to double shear test. The results show that the failure load, debonded load, the maximum of strain and peak value of shear stress decreased in different degrees under the freeze-thaw conditions, extra damage to bonded interface is caused by sustained load. In addition, the mechanism on behavior of bonded joints under sustained load is analyzed after freeze-thaw cycles.