高温后钢筋-混凝土界面黏结性能分析  

Analysis of Bond Behavior of Steel Bar-to-concrete Interface After Exposure to Elevated Temperatures

作　　者：周默苇 高皖扬 胡克旭[3] ZHOU Mo-wei;GAO Wan-yang;HU Ke-xu(School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Department of Disaster Mitigation for Structures,Tongji University,Shanghai 200092,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]上海交通大学海洋工程国家重点实验室,上海200240 [3]同济大学结构防灾减灾工程系,上海200092

出　　处：《建筑科学与工程学报》2020年第6期91-99,共9页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(51978398);上海市“科技创新行动计划”自然科学基金项目(19ZR1426200)。

摘　　要：基于均匀分布压力作用的厚壁圆筒模型,将钢筋混凝土拉拔试件变形钢筋周围的受高温损伤混凝土保护层按应力状态分为内外两部分,对内层开裂混凝土认为其产生弥散裂缝,并考虑其抗拉软化特性,同时引入高温后混凝土弹性模量、抗拉强度、断裂能的劣化,通过对受高温损伤钢筋-混凝土间黏结破坏时的极限状态进行理论分析,推导得出高温后钢筋-混凝土界面黏结强度的计算方法,建立了与钢筋、混凝土的尺寸、材性相关的高温后钢筋-混凝土界面黏结强度模型。基于混凝土开裂半径与端部滑移之间的线性关系,建立了高温后界面黏结应力-端部滑移关系。对模型计算结果与已有高温后钢筋与混凝土黏结性能试验所得数据进行比较,共对比了118组黏结强度、15组黏结应力-端部滑移关系。结果表明:该理论分析模型具有很高的准确性,可广泛适用于不同参数拉拔试验的高温后界面黏结强度的分析与预测。Based on the thick-walled cylinder model with uniform pressure at inner surface,the damaged concrete cover around the deformed bar was divided into two parts according to the stress state,including a partially cracked inner part and an uncracked outer one.For the inner cylinder,the smeared cracking assumption and tension softening behavior of the cracked concrete was taken into account with the stiffness reduction along the radial direction.Also,the reductions in the elastic modulus,tensile strength and fracture energy of concrete after exposure to elevated temperatures were properly considered.Based on the theoretical analysis of the ultimate splitting failure between steel bar and concrete damaged by high temperatures,the calculation method and analytical model of the interfacial bond strength between steel bar and concrete after exposure to high temperatures was deduced,which was related to the size and material properties of steel bar and concrete.Moreover,a linear relationship between the radius of the inner cracked cylinder and the end slip of the reinforcing steel bar was proposed,and thus the interfacial bond stress-slip relationship was obtained.The accuracy of the analytical model was validated by comprising the predicted results with available pull out test data on the steel bar-to-concrete interface(including 118 bond strength data and 15 bond stress-end slip curves).The results show that the analytical model has good accuracy,and can be widely used for the analysis and prediction of interfacial bond strength after high temperature in drawing test with different parameters.

关 键 词：钢筋混凝土结构 黏结性能 理论分析模型 高温后 界面 

分 类 号：TU375[建筑科学—结构工程]