硫酸盐干湿循环作用下CFRP-黏土砖界面黏结性能试验研究

Drying and watering cycle of sulfate’s influence on the adhesion of the interface of the bricks of burnt clay

通过单面剪切试验装置对硫酸盐干湿循环作用后的CFRP-黏土砖试件进行加载,研究硫酸盐干湿循环作用下CFRP-黏土砖界面黏结性能退化规律。研究结果表明:界面破坏形态随硫酸盐干湿循环由剪切破坏转变为黏结破坏,界面有效黏结长度和承载力随硫酸盐干湿循环时间在初期均有所增长,后期均呈下降的趋势。通过引入硫酸盐干湿循环影响系数,提出了硫酸盐干湿循环作用下CFRP-黏土砖界面黏结强度模型。通过与试验值对比,本文建议的模型可以准确预测硫酸盐干湿循环作用下界面黏结强度的退化规律。

Through a simple shear test device,the loading experiment was carried out to the CFRP-brick pieces after the effect of sulfate drying and wetting cycles was considered.The degradation law of CFRP-brick interfacial bond performance was studied with the drying and wetting cycle times.The experiment results are as follows.The interface destruction patterns change from shear destruction to bonding destruction with the dry and wet cycle of sulfates.The interfacial bond strength,the interfacial fracture energy and the effective bond length increase at the initial stage,and at the later stage,it has a trend of decrease.By introducing the influence coefficient of sulfate drying and wetting cycles,the bond strength model of CFRP-brick interface under sulfate drying and wetting cycles was established.By comparing the experimental values,the law of degradation of interfacial bond strength under the function of the sulfate drying and wetting cycles could be accurately predicted by the model which is proposed in this paper.