钢筋混凝土冻融损伤黏结滑移本构模型及其在构件中的应用  

Bond-slip model of freeze-thaw damaged reinforced concrete and its application for members

作　　者：李磊[1] 王卓涵 张艺欣 郑山锁[1] LI Lei;WANG Zhuohan;ZHANG Yixin;ZHENG Shansuo(School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《建筑结构学报》2021年第9期213-222,共10页Journal of Building Structures

基　　金：国家科技支撑计划(2013BAJ08B03);陕西省自然科学基础研究计划(2016KJXX-93)。

摘　　要：钢筋混凝土(RC)构件在冻融循环作用下易产生黏结性能的退化,以冻融损伤RC构件为对象,研究其纵筋的黏结滑移行为。通过分析冻融作用对混凝土与钢筋界面黏结行为的影响,将黏结性能的退化归因于混凝土强度退化和保护层约束效应退化,并以钢筋混凝土黏结滑移本构和冻融黏结滑移试验结果为基础,建立了适用于冻融损伤混凝土的黏结滑移本构模型。基于已有拉拔试验数据,对所提模型的精度和可靠性进行验证。结合所提模型及微元算法进一步得到冻融损伤纵筋滑移模型,采用非线性梁柱单元与零长度截面单元串联的组合方式,将该纵筋滑移模型应用于零长度截面中的钢筋纤维本构,建立了可考虑黏结滑移行为的冻融损伤RC纤维模型。根据6榀冻融损伤RC框架柱拟静力试验结果对该纤维模型的准确性进行验证,并采用仅考虑冻融损伤混凝土强度退化的纤维模型进行辅助验证。结果表明:相比已有黏结滑移本构,所提模型可更为准确地反映冻融损伤混凝土与钢筋界面的黏结滑移行为全过程;相比纤维模型,所提冻融损伤RC纤维模型的标准化滞回力误差和滞回耗能误差分别降低了8.7%和37.0%,且可更为准确地计算冻融损伤RC框架柱的滞回曲线及耗能能力。The bond between reinforcement and concrete is vulnerable to be freeze-thaw damaged. This paper aims at the bond-slip behavior of freeze-thaw damaged reinforced concrete(RC) component. By analyzing the effect of freeze-thaw on bonding mechanism between concrete and steel bar, an effective method was used in the modeling: the degradation of bond performance was caused by degradation in strength and cover effect of concrete. Based on bond-slip model of reinforced concrete and experimental results, a modified bond-slip model of concrete subjected to freeze-thaw damage was proposed. Through the comparison with existing pull-out test results, the proposed model was proved to be accurate and reliable. A stress-slip model of longitudinal bar subjected to freeze-thaw damage was obtained by combining the infinitesimal method and the proposed model. A fiber model considering bond-slip behavior was established by using nonlinear beam-column element and zero-length section element. The longitudinal bar slip model was applied as constitutive model of the reinforced fiber element with zero-length. The accuracy of the proposed fiber model was verified by the quasi-static experimental results of six freeze-thaw RC frame columns. The fiber model considering only concrete strength degradation was used for auxiliary verification. The results show that compared with existing bond-slip model, the proposed bond-slip model could more accurately simulate the whole process of bond-slip behavior between freeze-thaw damaged concrete and longitudinal bars. Compared with the existing fiber model, the normalized hysteretic force error and the normalized hysteretic energy error of the proposed fiber model are reduced by 8.7% and 37.0%, respectively. The hysteretic curves and hysteretic energy dissipation capacity of the freeze-thaw RC frame column could be accurately predicted by the proposed fiber model.

关 键 词：钢筋混凝土 冻融损伤 黏结滑移模型 纤维模型 滞回性能 

分 类 号：TU375[建筑科学—结构工程] TU311.41