考虑界面黏结滑移影响的钢-BFRP复合筋混凝土柱变形能力研究

Based on a newly proposed concrete structure reinforced by steel-basalt fiber reinforced polymer (BFRP) composite bar (SBFCB) by the researcher’s group, this application report is focused on the deformation capacity of SBFCB reinforced concrete columns considering SFCB-concrete bonding behavior. Deepening the applicant’s research during doctoral study, BFRP is selected for concrete columns with longer elongation rate and higher performance/cost ratio. The key parameters of the concrete column displacement capacity are the bonding performance between SBFCB and concrete, equivalent plastic hinge length, and strain penetration effect of the anchored SBFCB. Firstly, the bonding test under cyclic loading will be conducted with different SBFCB surface rib parameters and different surface treatments. The failure mechanism and its effect on the column’s plastic hinge length will be studied. Secondly, the influence of loading history on the SBFCB column’s accumulated damage degree will be examined via quasi static test, the maximum displacement and residual displacement will be discussed. The loading history will be in increase sequence or decrease sequence with the same input energy. The degradation of column’s bearing capacity will be studied through horizontal cyclic loading with a constant column tip drift level. Thirdly, the dynamic response of SBFCB column under the excitation of near fault ground motions (with acceleration or velocity pulse) will be analyzed numerically and experimentally. The dynamic experiment includes pseudo dynamic test and shaking table test. The maximum displacement capacity, residual displacement, and plastic hinge development will be evaluated. The corresponding displacement fragility index will be analyzed based on statistic datum. Finally, the displacement-based (maximum and residual displacement) seismic design method of SBFCB reinforced concrete columns will be proposed according to the above experimental test and numerical simulation.

针对课题组提出的具有高震后可修复性的钢-玄武岩纤维（BFPR）复合筋（SBFCB）混凝土柱及其抗震结构，申请者在博士期间研究基础上，指出研究界面黏结滑移影响下SBFCB砼柱最大变形和残余变形的必要性和创新性。首先，研究考虑黏结性能影响的SBFCB砼柱的最大变形能力评价方法，关键参数包括：等效塑性铰长度、塑性铰区SBFCB与砼界面黏结性能、锚固区SBFCB应力-滑移伸长效应等。其次，研究加载路径（不同地震波）对SBFCB砼柱残余位移的影响，比如①等能量输入时，加载位移从小到大与从大到小对SBFCB砼柱损伤累积的差别；②等位移往复加载时承载力退化特性等。然后，在拟静力试验研究基础上，选择含脉冲近场地震波对SBFCB砼柱进行基于可靠性的最大位移和残余位移易损性评价研究。最后，基于试验结果和多参数数值分析，提出SBFCB砼柱基于最大位移和残余位移的抗震设计方法。

本项目基于钢和纤维复合材料（FRP）的优势互补特征，在课题组工厂化生产质量稳定的钢-连续纤维复合材料筋（SFCB）基础上，对考虑界面粘结滑移的SFCB增强混凝土柱变形能力的重要影响因素进行了研究。首先针对SFCB受压力学性能进行了试验和理论分析，提出了考虑屈曲的SFCB全区间本构关系模型；然后开展了截面层次上复合配筋混凝梁弯曲变形性能理论分析，研究了等效配筋率、二次刚度比、FRP断裂应变等关键参数的影响，并进行了相应混凝土梁的静力加载试验来研究构件层次的弯曲变形能力；最后，进行了全粘结和部分无粘结混凝土柱静力性能试验，研究其开裂、骨架曲线、滞回耗能、塑性铰区应变分布等特征。本项目在试验和理论分析基础上，进一步加深了对新型复合配筋混凝土梁变形能力中弯曲变形分量及界限配筋率的认识，在本项目资助下，申请人获得和本项目有直接继承关系的国家自然科学基金面上项目，将开展装配式复合配筋混凝土柱基本性能及其评价方法研究。