二次受力下HDC加固RC梁受弯性能试验研究

Experimental study on flexural performance of RC beams strengthened with HDC under secondary load

摘要

为探究高延性混凝土(high ductile concrete，HDC)的拉伸与应变硬化性能对受损钢筋混凝土(reinforced concrete，RC)梁受弯性能的改善效果，设计6个HDC加固梁和1个对比梁四点弯曲静力试验，通过调整HDC加固层厚度和内置钢筋网的加固方式，结合二次受力条件下的材料应变分析，研究受损RC梁加固后的整体破坏形态、受弯承载力以及变形能力。结果表明，HDC加固可有效延缓裂缝扩展，改善试件的脆性破坏模式。当加固厚度为10mm且上下两端均内置钢筋网片时，试件的抗弯承载力和变形能力可提升35.44%和187.03%；同时基于极限平衡理论推导出HDC加固试件受弯承载力计算公式，结果与试验值吻合较好，可为HDC加固梁抗弯性能研究提供一定的参考。

Abstract

To investigate the effectiveness of high ductile concrete (HDC) in improving the flexural performance of damaged reinforced concrete (RC) beams, six HDC-reinforced beams and one control beam were designed for four-point static flexural tests. By adjusting the thickness of the HDC reinforcement layer and the reinforcement method with embedded steel mesh, the post-reinforcement damage morphology, flexural capacity, and deformation capacity of the beams under secondary stress conditions were analyzed. Material strain analysis was also conducted to evaluate structural behavior. The results show that HDC reinforcement effectively delays crack propagation and mitigates brittle failure modes. When a 10mm HDC layer with upper and lower built-in steel mesh was applied, the flexural load capacity and deformation capacity of the specimens can be increased by 35.44% and 187.03%, respectively. Furthermore, based on the limit equilibrium theory, a calculation formula for the flexural capacity of HDC-strengthened specimens was derived, and the results agree well with the experimental values, providing a certain reference for the study of the flexural performance of HDC-strengthened beams.

关键词

高延性混凝土 / 加固RC梁 / 二次受力 / 受弯承载力 / 变形能力

Key words

high ductile concrete / reinforced RC beam / secondary load / flexural capacity / deformation capacity

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基金资助

国家自然科学基金项目(52079109)

国家自然科学基金项目(51408487)

陕西省自然科学基础研究计划项目(2024JC-YBMS-425)