Moisture and Temperature Effects on Interface Mechanical Properties for External Bonding
In order to develop rational guidelines for strengthening by external bonding, it is necessary to clarify longtermperformance of interfacial bonding property. In this paper, moisture effects on bonding properties atFRP–concrete interface and temperature/moisture effects on bonding properties at PCM–concrete interfaceare presented. Shear bond strength of FRP–concrete interface is affected by moisture because resin–concreteadhesion strength is affected by moisture. Among tested CFRP external bonding systems, wet-layup CFRPsystems all show the strength reduction, while prefabricated CFRP systems all show the strength increase afterimmersion. The bond stress–slip relationship and interfacial fracture energy also change, which can explainthe change in shear bond strength. The reduction in shear bond strength does not show clear dependencyon resin strength/stiffness reduction. The observed big variation in shear bond strengths reported in paststudies can be explained by difference in interface roughness, since chemical bond is affected by moisturebut mechanical bond is not. Tension/shear bond strength of PCM–concrete interface is affected significantlyby temperature but less by moisture. The tensile/shear bond strength is less than tensile/shear strength ofconstituent materials (PCM and concrete). The reduction in tension/shear bond strength depends on thereduction in tensile/shear strengths of PCM and concrete and then estimated by proposed equation whichis a function of PCM and concrete strength. The ultimate loads of beams strengthened by PCM overlay canbe predicted by the proposed model in which the proposed tensile/shear bond strength is applied. Underhigh temperature, the failure mode can be changed from flexure/shear failure to debonding failure due to thereduction in shear bond strength.
Ueda Tamon Justin Shrestha Khuram Rashid Zhang Dawei
Division of Engineering and Policy for Sustainable Environment, Faculty of Engineering,Hokkaido Univ College of Civil Engineering and Architecture, Faculty of Engineering, Zhejiang University, China
国际会议
The 5th International Conference on the Durability of Concrete Structures(第五届混凝土结构耐久性国际学术会议)
深圳
英文
3-12
2016-07-01（万方平台首次上网日期，不代表论文的发表时间）