| At present, the reinforcement and reconstruction is being developed rapidly in the world and the focus of building industry is being transferred gradually. Strengthening of enlarge section method with self compacting concrete is an economical and efficient method that is being widely used. In this paper, the strengthen technology is studied by experiment and theoretical analysis。The test adopt post-tensioning unbonded prestressed steel strand for simulating the load, to reflecting the real stress of the unit。The main contents and achivements are as follows:The expriement with five axially loaded reinforced concrete column is carried on, one column is not strengthened for contrasting , the other four columns are strengthened by enlarge section method with self-compacting concrete. Based on the study of experiment, the thesis analyses the failure pattern, strength, stiffness of the strengthening columns under the stress excess of steel and the strain delay of concret caused by secondary loading. And the initial stress level index is taken as the focal point in this paper. Some conclusions were obtained as follows:1.The normal section bearing capacity of RC column reinforced rises very notable by enlarge section method with self-compacting concrete.2.After axially loaded RC column reinforced by enlarge section method, the ultimate limit bearing capacity is not simply superposition with the new and old concrete bearing capacity, but it reduces with the stress level indexβincreasing.3.Considering the intensity using coefficient of the additional material and confinement by the new increased concrete to the core concrete, a calculation method of the normal bearing capacity is presented.,and the calculation results come with a good agreement with the measured data.4.RC column reinforced by enlarge section method with self-compacting concrete was used in an actual project ,the effect of reinforcement is obvious. |
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