火灾后锈蚀钢筋地聚物混凝土黏结性能研究

Experimental study on bond performance of corroded reinforcing steel and geopolymer concrete after a fire

  • 摘要: 本文旨在探究高温及钢筋发生锈蚀对钢筋地聚物混凝土结构黏结性能的影响规律。总结不同目标温度(30、100、200、400、600、800℃)情况后锈蚀钢筋与地聚物混凝土黏结-滑移规律,采用三段式(上升段、下降段、残余段)表达式建立无量纲黏结-滑移模型。试验设计通过电化学加速锈蚀达到钢筋目标锈蚀率(0、1、2、3、4、5%)后进行高温处理,随后进行中心拉拔试验以评估黏结强度。研究表明:当温度升高和锈蚀率增加到一定程度后均降低了钢筋与地聚物混凝土之间的黏结强度;基于试验数据,建立了黏结-滑移本构模型以定量描述在不同温度与锈蚀状态下的黏结行为,该模型不仅揭示了温度和锈蚀对黏结滑移的影响机制,还为预测在发生火灾后钢筋地聚物混凝土结构的设计与应用提供了重要的理论依据。

     

    Abstract: The purpose of this paper was to investigate the influence of high temperature and corrosion on the bond performance between reinforcing steel and geopolymer concrete. Based on the bond-slip law of corroded reinforce and geopolymer concrete after target temperature (30、100、200、400、600、800℃), the dimensionless bond-slip model was established by using a three-segment expression. The experimental design achieved the target corrosion levels of steel reinforcement (0、1、2、3、4、5%) by electrochemical acceleration method, followed by being treated with high temperature heating, and ultimately being tested with the pull-out test to evaluate the bond strength. The study shows that: when the temperature increases and the corrosion degree increases to a certain extent, the bond strength between the reinforcing steel and the geopolymer concrete is significantly reduced; based on the experimental data, developing a bond-slip constitutive model to quantitatively describe the bonding behavior at different temperatures and corrosion regimes. The model not only reveals the influence mechanism of temperature and corrosion on bond and slip, but also provides an important theoretical basis for the design and application of reinforced geopolymer concrete structures after a fire.

     

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