钢-连续纤维复合筋及其增强混凝土结构研究现状

Research status of steel-FRP composite bar and its reinforced concrete in civil engineering application

钢连续纤维复合筋(SFCB)由内芯钢筋与纤维增强复合材料(FRP)外包覆层复合而成,基于钢筋和FRP的优势互补,SFCB具有良好的耐腐蚀性能与稳定的屈服后二次刚度,在新建结构和加固领域具备广泛的应用前景。本文介绍钢与FRP复合的不同产品(筋、板、索等)及其力学性能特征,复合产品的受拉性能可以通过复合法则进行较好的预测,而SFCB的往复拉压性能由于内芯钢筋和外侧FRP相互作用而产生“双向削弱效应”。对SFCB/混凝土界面黏结性能及其增强混凝土梁、板、柱性能的研究进展进行介绍,SFCB/海砂混凝土的短期和长期黏结性能均表现良好,在盐溶液中浸泡6个月后其黏结性能无明显减弱;在相同柱顶侧移下,SFCB增强混凝土柱相对于普通钢筋混凝土(RC)柱的柱底曲率需求较小,结合集束等高效配筋形式可以实现SFCB增强混凝土柱变形能力的进一步有效控制;振动台试验表明:SFCB增强混凝土柱的塑性铰区应变更为均匀,有利于减小结构的震后残余变形。通过梳理SFCB及其增强混凝土结构研究现状,对提升本领域研究水平和促进工程应用推广有一定的参考价值。

A steel-fiber reinforced polymer(FRP)composite bar(SFCB)is composed of inner steel bar and outer wrapped FRP.Based on the complementary advantages of steel bar and FRP,SFCB has great corrosion resistance and stable post-yield stiffness,providing broad application prospects in new structures and the strengthening of existing structures.This paper first introduced different steel-FRP composite products(bars,plates,cables,etc.)and their mechanical properties.The tensile performance of steel-FRP composite products could be well predicted by the rule of mixtures.While under cyclic loading,a weakening effect occurred in SFCB due to the interaction between the inner steel bar and the outer FRP.Then,the research progress on bond behaviors between SFCB and concrete,the performance of concrete beams,slabs and columns reinforced by SFCB were introduced.The short-and long-term bond performance between SFCB and marine sand concrete were acceptable,and no significant decrease appeared in bond behavior after 6 months of immersion in salt solution.The curvature requirement of column base in SFCB reinforced concrete column was smaller than that in the ordinary RC column with the same lateral displacement,therefore,further effective control of the deformation capacity of SFCB reinforced concrete columns could be achieved by considering efficient reinforcement forms(such as bundled reinforcement).The shaking table test showed that the strain distributed more evenly in the plastic hinge zone of the SFCB reinforced concrete column,which was beneficial to reduce the residual deformation of structure after earthquake.By reorganizing the research status of SFCB and its reinforced structures,it can be valuable for improving the level of research and potential engineering applications.