考虑应变率效应的FRP-混凝土界面正拉黏结性能研究

Experimental analysis on interfacial tensile bonding performance between FRP and concrete concerning strain rate effect

为揭示FRP-混凝土界面正拉黏结性能的应变率效应,对60个标准试件进行快速荷载下的正拉试验,研究了加载速率、FRP种类及混凝土强度等级3个参数对FRP-混凝土界面正拉黏结强度的影响规律.在欧洲规范建议的幂函数模型基础上,通过回归拟合建立了考虑应变率效应的正拉黏结强度预测模型,并验证其可靠性.结果表明:正拉黏结强度随着加载速率的增大而提高;在中高加载速率时,加载速率对正拉黏结强度的影响有减弱趋势;黏贴CFRP的试件正拉黏结强度明显高于黏贴BFRP的试件;正拉黏结强度随着混凝土强度等级的提高而提高.

In order to reveal the strain-rate effect on the tensile bonding performance of FRP-concrete interface, based on the tensile test using sixty standard specimens under fast load, we investigate the effects of loading rate, FRP type and concrete strength grade on the tensile bonding strength of FRP-concrete. By applying the power function model proposed by European researchers, an estimated model of the tension bond strength concerning the strain rate is presented using regression fitting technique. The test results show that the tensile bonding strength increases along with the increase of loading rate, and the influence of loading rate on the tensile bonding strength is reduced when the loading rate turns to either medium or high level. The tensile bonding strength of the specimen pasted with CFRP is found to be significantly higher than that of BFRP. Moreover, the tensile bonding strength increases as the concrete strength grade goes up.