Study On Mechanical Performance Of Composite Constrained RC Column With BFRP Grid Enhanced ECC

Be aimed at the problems of aging easily,poor permeability and durability in repairing and strengthening concrete structures with single fiber reinforced polymer(FRP),a new type of composite strengthening technology combining FRP grid and engineered cementitious composite(ECC)with superior performance emerges as the times require.Based on this,the research topic of composite constrained reinforced concrete(RC)column with BFRP grid enhanced ECC was put forward in this paper.The composite column is composed of reinforced concrete column as the core,ECC embedded in BFRP grid is wrapped to form a composite reinforcement layer,and its mechanical performance has been further improved.At present,there are few studies on composite constrained reinforced concrete column with BFRP grid enhanced ECC at home and abroad,so it is necessary to carry out the research on this kind of composite columns.Based on the current researches about this topic,ABAQUS software was used to investigate the performance under eccentrically loaded and seismic of composite constrained reinforced concrete column with BFRP grid enhanced ECC under different working conditions by numerical simulation method,which provides reference for future engineering practice and code formulation.The research work of this paper includes the following five aspects:1.Based on the summary of the research status and theoretical research of FRP grid reinforced ECC composites and FRP confined concrete structure at home and abroad,the complete basic preparation for the research of the subject was made.2.The finite element model of composite constrained reinforced concrete column with BFRP grid enhanced ECC was established by ABAQUS.The load displacement curve and ultimate bearing capacity of the simulation results were compared with the existing test data to verify the constitutive model of the selected material and the rationality of the model.3.The mechanical performance of 39 composite constrained reinforced concrete columns with BFRP grid enhanced ECC under eccentric compression were studied.The influences of eccentricity,BFRP grid size,ECC thickness,slenderness ratio and concrete strength on the composite columns were analyzed.4.The seismic behavior of 18 composite constrained reinforced concrete columns with BFRP grid enhanced ECC under low cyclic loading were studied.The effects of axial compression ratio,ECC thickness,BFRP grid size and concrete strength on hysteretic curve,skeleton curve,energy consumption,ductility and stiffness degradation were investigated.5.According to the influence of design parameters on the mechanical performance of composite column,reasonable design parameters were given.