箍筋约束ECC轴心受压性能试验研究

发布时间：2018-06-02 12:09

  本文选题：圆形截面短柱 + 纤维增强水泥基复合材料　； 参考：《建筑结构学报》2017年07期

【摘要】：为研究箍筋约束工程纤维增强水泥基复合材料(ECC)的受压性能,对12组共36个箍筋约束的配筋ECC圆形截面短柱进行了轴心受压试验,分析了箍筋屈服强度和间距、ECC强度与PVA纤维体积掺量对约束ECC应力-应变曲线的影响。结果表明:试件的破坏形态均为纵筋压屈、核心ECC压碎,由于PVA纤维的桥接作用,提高了柱的整体性,保护层ECC外鼓但并未剥落;提高箍筋屈服强度、减小约束箍筋间距、采用低强度ECC及增加PVA纤维体积掺量,约束ECC应力-应变曲线的下降段较为平缓,短柱的延性得到改善,相对于较强的箍筋约束作用,PVA纤维对约束ECC变形的影响则较小。基于试验结果的分析,提出了考虑有效约束指标与PVA纤维体积掺量的箍筋约束ECC峰值应力及其对应应变计算式,建立了约束ECC应力-应变全曲线方程,计算曲线与实测曲线吻合较好。
[Abstract]:In order to study the compressive properties of concrete matrix composites reinforced by fiber reinforced by stirrups, the axial compression tests of 12 groups of reinforced ECC circular section short columns with 36 stirrups were carried out. The effects of yield strength and spacing of stirrups on the stress-strain curves of confined ECC were analyzed. The results show that the failure patterns of the specimens are longitudinal tendons buckling and core ECC crushing. Because of the bridging effect of PVA fibers, the integrity of columns is improved, the outer bulging of protective layer ECC is not flattened, the yield strength of stirrups is increased, and the spacing of confined stirrups is reduced. With the use of low strength ECC and increasing the volume content of PVA fiber, the decreasing section of the stress-strain curve of confined ECC is relatively smooth, the ductility of the short column is improved, and the effect of PVA fiber on the deformation of confined ECC is smaller than that of the strong stirrups. Based on the analysis of the test results, a formula for calculating the peak stress of stirrups constrained ECC and its corresponding strain considering the effective constraint index and the volume content of PVA fiber is proposed, and the whole stress-strain curve equation of constrained ECC is established. The calculated curve is in good agreement with the measured curve.
【作者单位】： 河南理工大学土木工程学院;
【基金】：国家自然科学基金项目(51208183) 河南省科技攻关项目(132102310312) 河南省高等学校青年骨干教师资助项目(2014GGJS-043) 河南省高等学校重点科研项目(17A560005)
【分类号】：TB332
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本文编号：1968707