Stuty On Bearing Capacity For RC Strengthened Columns Based On Confined Concrete

Because of concrete carbonization， alkali-aggregate reaction， corrosion ofrainwater，the defects of antifreeze and impermeability and corrosion of steel bar makethe concrete columns do not meet the normal usage function，as well as the design andconstruction defects and other reasons，the concrete column need to be reinforced forlacking of bearing capacity. This paper mainly studies the experimental investigation ofstrengthened reinforced concrete columns，however，for this method of reinforcement，this subject focus on using the theory of constraint to strengthen the joint zone，formingthe effective constraint area and ensuring upper loads on strengthened column smoothlytransfer to reinforcing area，namely the region of reinforced concrete can completelyinvolved in the force.To investigate the confinement mechanism in the joint zone，the mechanism ofload towards Z and the influencing parameters of constrain effect in the constraint area，main researches been done list as follows：①This paper summarize the classical theory of constraint，gather and arrange thebehavior of axially loaded concrete columns confined with ordinary hoops，as well asthe result of analysis and experiment，analyze the influencing factors of confinementmechanism and confinement effect so as to provide theoretical basis for this subject.②Found the finite model of this subject via the large universal finite elementsoftware ABAQUS.Meanwhile，analyze the column with covered concrete which isconsidered the part of increased concrete to completely involve in the force，thenanalyze this column ultimate compressive strength，compare bearing capacity with thereinforce columns which are abolished lapping layers.At the meantime, comparebearing capacity with the standard of strengthening concrete.Finally, analyze thefeasibility of this reinforcement method.③Analyze the factors which influence confining effect of the joint via the finiteelement software，and abtain the bearing capacity under the condition of differentconstraints，then,compare it with the bearing capacity of the no-lapping layers，so as todrew the conclusion the upper load is smoothly transferred to the inferior of constraintarear under the condition of obolishing the lapping layers，ensure the convered concreteto participate in taking load together with the core columns.Meanwhile，simplify therestriction mechanism，then give the simplified formula to compare it with finite element analysis results，lay a theoretical foundation for the experiment.④According to finite element analysis results，pouring the components for thefurtherresearch of experiment，then compare with the finite model and give the opinion ofimproved methods，verify the feasibility of this reinforcement method.