极地低温下CFRP筋与混凝土的黏结性能

Bonding Behavior between CFRP Bar and Concrete at Polar Temperature

开展了碳纤维增强聚合物(CFRP)筋混凝土试件的拉拔试验,考虑混凝土强度、CFRP筋直径、黏结长度、保护层厚度等参数,分析了极地低温对CFRP筋与混凝土黏结性能的影响规律.结果表明:与常温相比,极地低温降低了CFRP筋与混凝土的黏结性能,但在18~-80℃范围内,随着温度的降低,其黏结强度并非呈现单一趋势的变化规律;随着CFRP筋直径和黏结长度的增加,CFRP筋与混凝土的黏结强度呈降低趋势,提高混凝土强度或增大保护层厚度将提高其黏结强度;极地低温条件下CFRP筋与混凝土的黏结界面趋于脆性,易发生突然且随机的界面破坏,而不易发生混凝土的劈裂破坏.

Pull-out tests were carried out to investigate the effects of polar temperature on the bonding behavior between carbon fiber reinforce polymer(CFRP)bars and concrete by considering several parameters,including concrete strength,bar diameter,bond length,and cover thickness.The experimental results show that the bonding behavior between CFRP bar and concrete is weakened at polar temperature compared with that at normal temperature,but it reveals a nonmonotonic trend at temperatures ranging from 18℃to-80℃.The bond strength tends to decrease with the increase of bar diameter and bond length,while increases with the enhancement of concrete strength and cover thickness.The bond interface between CFRP bar and concrete tends to be brittle and prone to sudden and random failure,whereas concrete splitting hardly occurs at polar temperature.