Bond Strength of CFRP Laminates in UHPC at Elevated Temperature
摘要
Studies on the application of carbon fibre reinforced polymer (CFRP) laminate strips at high temperature have been limited. Because of the growing demand for CFRP based ultra-high-performance concrete (UHPC) construction, investigating the behaviour of these materials under elevated temperatures is crucial for structural applications where fire exposure is a major concern. This paper studies the effect of elevated temperature on the bond degradation of CFRP strips of various configurations in UHPC. The CFRP strips were fabricated from unidirectional carbon fabric and epoxy resin with a width of 25 mm and 6.6 mm thickness. Experimental investigations were conducted for three different temperature protocols: steady state temperature, transient temperature, and residual tests with room temperature tests as controls. The specimens were exposed to five different temperatures ranging from 25 ℃ to 200 ℃ as measured at the concrete to bar interface. Under steady state conditions the failure load and bond strength dropped below 34% of the room temperature strength. Conversely, the residual bond strength showed a small reduction relative to specimens tested at room temperature. The findings presented in this paper have broad applicability to UHPC including CFRP laminates in high temperature and fire scenarios.