地聚物混凝土-玻璃纤维增强复合材料筋界面黏结行为的梁式试验研究

Research on Interfacial Bonding Performance Between Geopolymer Concrete and GFRP Bars Based on Beam Test

在“双碳”目标下,采用绿色低碳的地聚物混凝土替代高碳排放的硅酸盐水泥混凝土是目前的研究热点之一。以粉煤灰基地聚物混凝土为对象,基于梁式试验开展弯拉作用下地聚物混凝土-玻璃纤维增强复合材料(GFRP)筋界面黏结性能的研究,探明了不同混凝土强度、类型对地聚物混凝土-GFRP筋界面黏结性能的影响。结果表明:在与GFRP筋黏结的试验中,由于地聚物混凝土与硅酸盐水泥混凝土存在力学性能的差异,导致两者虽然有相似的破坏模式,但在不同混凝土强度下界面的破坏机制不同,黏结刚度、黏结强度随混凝土变化的规律也不同;对已有的XUE模型和Bimodal模型进行形状系数的修正,通过对比分析,建立适用于地聚物混凝土-GFRP筋的黏结滑移本构模型。

In the context of the“dual-carbon goals”strategy,the use of green and low-carbon geopolymer concrete instead of high-carbon emission Portland cement concrete is currently a hot research topic.This paper focused on fly ash-based geopolymer concrete and conducted a beam test to study the interfacial bonding performance between geopolymer concrete and glass fiber reinforced polymer(GFRP)bas under bending and tensile loads.The influence of different concrete strengths or types on the interfacial bonding performance between geopolymer concrete and GFRP bars was determined.The results showed that due to the difference in mechanical properties between geopolymer concrete and Portland cement concrete,although they showed similar failure modes in the tests with GFRP bars,the failure mechanism at the interface varied with different concrete strengths,and the bonding stiffness and strength also changed accordingly.Finally,the XUE model and Bimodal model were modified for shape factor,and a bond-slip constitutive model suitable for the interface between geopolymer concrete and GFRP bars was established through comparative analysis.This study provides a performance reference for green,low-carbon,and sustainable concrete materials.