极地低温下混凝土填充GFRP拉挤管黏结性能试验研究  

Experimental Study on Bonding Behavior of Concrete-Filled GFRP Pultruded Tubes at Arctic Low Temperatures

作　　者：谢剑[1,2] 王梦琴 李建军 王哲[1] Xie Jian;Wang Mengqin;Li Jianjun;Wang Zhe(School of Civil Engineering,Tianjin University,Tianjin 300354,China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education(Tianjin University),Tianjin 300354,China;Tianjin University Research Institute of Architectural Design and Urban Planning Co.,Ltd.,Tianjin 300073,China)

机构地区：[1]天津大学建筑工程学院,天津300354 [2]滨海土木工程结构与安全教育部重点实验室(天津大学),天津300354 [3]天津大学建筑设计规划研究总院有限公司,天津300073

出　　处：《天津大学学报（自然科学与工程技术版）》2024年第10期1100-1110,共11页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51978459,52278201).

摘　　要：纤维增强聚合物(FRP)管与混凝土之间的界面黏结是二者之间荷载传递的必要条件和共同作用的重要前提.为了探究混凝土填充GFRP管(CFFT)在极地等严寒环境下的黏结性能,在20~-80℃的不同低温条件下,对12个圆形和16个方形CFFT进行了推出试验,得到了GFRP管-混凝土界面的黏结-滑移曲线和典型破坏模式.研究了低温水平(T=20℃、-30℃、-60℃、-80℃)、界面类型(黏砂和未黏砂)、径厚比(D/t=30.0、31.3、37.5、50.0)、截面类型(圆形、方形)和FRP管制造工艺(拉挤成型、纤维缠绕)对黏结性能的影响.试验结果表明:除推出破坏外,部分方形黏砂试件表现为角部开裂;低温改善了GFRP管与混凝土的黏结性能,且20~-60℃温度段对黏结性能的影响强于-60~-80℃温度段;黏砂可显著提高CFFT的界面黏结强度(-60℃下,圆形黏砂试件黏结强度可增加到未黏砂试件的2.18倍,方形黏砂试件黏结强度可增加到未黏砂试件的7.93倍);D/t与黏结强度呈负相关;圆形CFFT的黏结强度高于方形CFFT;拉挤管的黏结强度低于纤维缠绕管,这表明GFRP管-混凝土的界面黏结强度主要受摩擦力(环向约束压力)影响.最后在试验的基础上,提出了CFFT在低温下黏结强度的预测模型.本研究可为CFFT构件在极地低温下的应用提供参考.The interfacial bond between the fiber-reinforced polymers(FRP)tube and concrete is crucial for load transfer,and it is an important prerequisite for their interaction.To investigate the bond behavior of concrete-filled GFRP tubes(CFFTs)in the Arctic and cold regions,a testing program with 12 circular and 16 square CFFTs was conducted under various low temperatures ranging from 20℃to-80℃.The bond stress versus slip curves and typical failure modes of the GFRP tube-concrete interface were obtained.The influences of different low temperature levels(T=20℃,-30℃,-60℃,and-80℃),inner surface texture(sand-coated or not),diameter to thickness ratio(D/t=30.0,31.3,37.5,and 50.0),cross-section types(circle,square),and FRP tube manufacturing technology(pultrusion,filament winding)on the bond behavior were investigated.The test results show that in addition to interface failure,some square specimens with sand-coating show corner cracking.Low temperatures improve the bond behavior of the GFRP tube and concrete.The influences of 20℃to-60℃on the bond behavior are stronger than those of-60℃to-80.Sand℃-coating can significantly improve the interfacial bond strength of CFFT.At-60℃,the bond strength of circular sand-coating specimens can be improved to 2.18 times in comparison to the specimens without sand-coating,and the bond strength of square sand-coating specimens can be improved to 7.93 times in comparison to the specimens without sand-coating.Increasing the D/t ratio reduces the ultimate bond strength.Circular CFFTs exhibit higher bond strength than square ones.Pultruded FRP tubes exhibit lower bond strength than the filament winding ones,which shows that the bond strength of a GFRP tube-concrete interface is affected by friction(circumferential confinement pressure).Finally,a prediction model based on experimental data for the ultimate bond strength of CFFT at low temperatures.This study can provide a reference for CFFT component application at low arctic temperatures.

关 键 词：极地低温 黏结性能 混凝土填充GFRP管 推出试验 

分 类 号：TU398.9[建筑科学—结构工程]