杨海峰, 马仙娣, 肖建庄, 张宇, 张天宝. 高温后单向侧压作用下混凝土与钢筋黏结-滑移性能研究[J]. 工程力学, 2021, 38(12): 118-124, 157. DOI: 10.6052/j.issn.1000-4750.2020.11.0843
引用本文: 杨海峰, 马仙娣, 肖建庄, 张宇, 张天宝. 高温后单向侧压作用下混凝土与钢筋黏结-滑移性能研究[J]. 工程力学, 2021, 38(12): 118-124, 157. DOI: 10.6052/j.issn.1000-4750.2020.11.0843
YANG Hai-feng, MA Xian-di, XIAO Jian-zhuang, ZHANG Yu, ZHANG Tian-bao. RESEARCH ON BOND-SLIP BEHAVIOR BETWEEN CONCRETE AND STEEL REBAR UNDER UNIAXIAL LATERAL PRESSURE AFTER HIGH TEMPERATURES[J]. Engineering Mechanics, 2021, 38(12): 118-124, 157. DOI: 10.6052/j.issn.1000-4750.2020.11.0843
Citation: YANG Hai-feng, MA Xian-di, XIAO Jian-zhuang, ZHANG Yu, ZHANG Tian-bao. RESEARCH ON BOND-SLIP BEHAVIOR BETWEEN CONCRETE AND STEEL REBAR UNDER UNIAXIAL LATERAL PRESSURE AFTER HIGH TEMPERATURES[J]. Engineering Mechanics, 2021, 38(12): 118-124, 157. DOI: 10.6052/j.issn.1000-4750.2020.11.0843

高温后单向侧压作用下混凝土与钢筋黏结-滑移性能研究

RESEARCH ON BOND-SLIP BEHAVIOR BETWEEN CONCRETE AND STEEL REBAR UNDER UNIAXIAL LATERAL PRESSURE AFTER HIGH TEMPERATURES

  • 摘要: 高温后混凝土与钢筋间的黏结性能影响钢筋混凝土结构的安全评估,实际工程中钢筋混凝土常承受侧向约束作用。为此,该文以高温温度和侧压力为参数,完成了48个钢筋混凝土试件的中心拉拔试验,分析侧压力对高温后试件破坏形态、峰值黏结应力、峰值滑移、残余黏结强度的影响规律,建立了峰值黏结应力随高温温度和侧压力变化的经验公式。将侧压下钢筋-混凝土黏结应力场简化为肋前混凝土挤压力和侧压力的线性叠加,并基于微观传力模型及高温后混凝土的多轴强度破坏准则推导计算了无侧压及单向侧压下的黏结强度理论。研究结果表明:侧压作用和高温温度直接影响试件破坏形态;随着侧压力增加,高温后混凝土与钢筋间的峰值黏结应力、残余黏结强度、峰值滑移逐渐增大,但温度达到500 ℃后,有侧压试件峰值滑移较无侧压试件小;黏结强度理论计算值与实测值较为吻合,能较好地预测高温后混凝土与钢筋间的黏结强度。

     

    Abstract: The bond performance between concrete and steel rebar after high temperatures (HT) affects the safety evaluation of reinforced concrete structure. In practical engineering, the reinforced concrete is often subjected to lateral pressure (LP). Therefore, forty-eight pull-out tests of steel rebar embedded in concrete were carried out with HT and LP as parameters. The effects of LP on failure pattern, peak bond stress, peak slip and residual bond strength of specimens after HT were analyzed, and the empirical formula for peak bond stress with HT and LP was also established. The bond stress field of reinforced concrete under lateral pressure was deemed as linear superposition of concrete extrusion pressure in front of ribs and lateral pressure, and the bond strength of specimens with/without uniaxial LP were then calculated based on the microscopic transfer model and multi-axis strength failure criteria of concrete after HT. The results show that: LP and HT have significant effect on failure pattern of specimens. As LP increases, the peak bond stress, residual bond strength and peak slip gradually increase, but the peak slips of specimens with LP are smaller than those of specimens without LP when HT reaches 500 ℃. The theoretical calculations agree well with test results, indicating that it can predict the bond strength between concrete and steel bar after HT.

     

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