动态单调荷载下约束再生混凝土单轴受压应力-应变全曲线方程

发布时间：2018-04-28 00:06

本文选题：再生混凝土 + 应变率效应　；参考：《土木工程学报》2017年08期

【摘要】：在MTS 815力学试验上,完成了81个箍筋约束再生混凝土短柱动态力学试验,分析约束再生混凝土在不同变率下的破坏特征。基于获得的应力-应变试验曲线,研究应变率效应、箍筋约束效应和再生粗骨料取代率对约束再生混凝土力学和变形性能的影响。根据应变率效应对约束再生混凝土力学和变形性能的影响规律,初步提出约束再生混凝土性能指标动态放大系数(DIF)模型。分析箍筋形式、箍筋间距、箍筋屈服强度和配箍率等因素对约束再生混凝土短柱力学行为的影响,初步提出约束再生混凝土性能指标约束放大系数(CIF)模型。分析表明,箍筋约束效应对再生混凝土的力学和变形性能有重要的影响,在很大程度上改善了再生混凝土的延性。研究再生粗骨料取代率对约束再生混凝土力学和变形性能的影响规律,提出取代率影响因子(RIF)模型。基于约束再生混凝土短柱动态试验数据分析,提出考虑应变率效应、箍筋约束效应和再生粗骨料取代率影响的约束再生混凝土应力-应变分析模型,定义受压应力-应变全曲线特征点参数,确定约束再生混凝土受压应力-应变全曲线方程。研究表明,应力-应变计算曲线和试验曲线吻合较好,验证了分析模型的合理性,为再生混凝土结构动力非线性分析和抗震优化设计提供研究基础。
[Abstract]:The dynamic mechanical tests of 81 stirrups confined recycled concrete short columns were carried out in MTS 815. The failure characteristics of confined recycled concrete at different rates of variation were analyzed. Based on the obtained stress-strain test curves, the effects of strain rate effect, stirrups constraint effect and recycled coarse aggregate replacement rate on the mechanical and deformation properties of confined recycled concrete are studied. According to the effect of strain rate effect on the mechanical and deformation properties of confined recycled concrete, a dynamic magnification factor (DIF) model is proposed. The effects of stirrups form, stirrups spacing, stirrups yield strength and hoop ratio on the mechanical behavior of confined recycled concrete short columns are analyzed. The analysis shows that the constraint effect of stirrups has an important effect on the mechanical and deformation properties of recycled concrete and improves the ductility of recycled concrete to a great extent. The influence of the replacement ratio of recycled coarse aggregate on the mechanical and deformation properties of recycled recycled concrete was studied. Based on the analysis of dynamic test data of confined recycled concrete short columns, a stress-strain analysis model of confined recycled concrete considering strain rate effect, stirrups constraint effect and replacement rate of recycled coarse aggregate is proposed. The characteristic point parameters of compressive stress-strain curve are defined and the stress-strain full curve equation of confined recycled concrete is determined. The results show that the stress-strain curve is in good agreement with the experimental curve, which verifies the rationality of the analytical model and provides a basis for dynamic nonlinear analysis and seismic optimization design of recycled concrete structures.
【作者单位】：同济大学;南阳师范学院;
【基金】：中国博士后科学基金(2014M550247,2015T80449) 国家自然科学基金(51608383) 河南省重点科技攻关项目(152102310027)
【分类号】：TU528

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