钢绞线(丝)网-聚合砂浆加固钢筋混凝土梁受弯性能研究

钢绞线(丝)网-聚合砂浆加固技术是一项新型加固工艺,具有耐火、耐腐蚀、耐老化、施工速度快等优点,已被逐渐应用于钢筋混凝土结构的加固补强中。采用该技术抗弯加固钢筋混凝土梁的受力性能可分为三个阶段:未裂阶段、裂缝阶段和破坏阶段。已有研究多数集中于加固混凝土梁正常使用阶段的抗弯性能分析,对受力纵筋屈服后破坏阶段的抗弯性能分析则鲜有涉及。该文在以往试验研究的基础上,采用换算截面法计算加固钢筋混凝土梁屈服阶段和极限阶段的等效刚度,对加固梁在集中荷载作用下抗弯性能全过程进行受力分析,并通过10根加固梁的试验数据对其验证,吻合良好。

STUDY ON FLEXURAL BEHAVIOR OF REINFORCED CONCRETE BEAM STRENGTHENED WITH STEEL WIRE MESH AND POLYMER MORTAR

Rehabilitation of reinforced concrete members with steel wire mesh and polymer mortar is a new method of structural strengthening with the advantages of resistance to fire,corrosion,ageing,and rapid construction speed.This new technique has been gradually applied in the strengthening of reinforced concrete structures.Existing test results indicated that the overall flexural behaviour of reinforced concrete beams strengthened with steel wire mesh and polymer mortar can be divided into three stages: precracking stage,cracking stage,and failure stage.The research conducted so far on the flexural rehabilitation of virgin RC beams in failure stage beyond the steel bar yield by using steel wire mesh composites is quite limited and of a preliminary and exploratory character,while the flexural behaviour of RC beams strengthened by steel wire mesh composites in the serviceability limit stage is rather extensive.Based on existing test results,a moment deflection model is developed by using a transformed section approach.The flexural behaviour of the strengthened specimens subjected to a four-point bending test was addressed.The suggested model was verified using the test data of 10 strengthened beams,and a good agreement between experiment and prediction values is achieved.