Experimental Investigation of Bond between High-Modulus CFRP and Steel at Moderately Elevated Temperatures

摘要

This paper presents the findings of a research study that was conducted to assess the effect of moderately elevated temperatures, up to 50 degrees C, on the bond behavior of steel beams strengthened with externally bonded high-modulus carbon-fiber-reinforced polymer (CFRP) plates. In the first phase of the testing, seven steel-CFRP bonded double-lap shear coupons were tested at different temperatures to characterize the bond behavior. In the second phase of testing, steel beams were strengthened with different lengths of high-modulus CFRP plates and loaded under four-point bending at 25, 40, and 50 degrees C. The test results indicate that the debonding load of bonded joints at 50 degrees C is between 56 and 116% greater than the debonding load of similar joints at 25 degrees C for the specific system tested in this study. This increase was attributed to an increase of the toughness of the tested adhesive at 50 degrees C despite the lower tensile strength and stiffness of the material. The research findings suggest that the proposed strengthening system for steel beams is suitable for application at service temperatures up to 50 degrees C. (C) 2016 American Society of Civil Engineers.