The Experimental Studies On Exterior Reinforcement Using Spiral Hoops For Reinforced Square-section Concrete Column

Application with strengthening the rapid development of technology and succeeding , Strengthen technology to develop quickly in our country in recent ten years, in this technological field, the domestic and international scholar has carried on fruitful research, acquire a great achievement. But because it has just risen, especially the theory and practice are out of step, make a lot of actual projects lack the guidance of the theory, lead to the fact wasting and unreasonable phenomenon. Especially adopt and strengthen the sectional way to the reinforcement of the concrete column more, or wrap up the way of angle steel outside.This paper direct independent reinforcement of column against, explore anneal reinforcing bar spiral hoops strengthen technology. On the basis of using the armored concrete column to wind silks to strengthen the experiment, Material: 16, long: wide =6, and 4 , long: wide =12 , study and wind the working performance of square-section column that the spiral hoops strengthens, studies the performance properties of the reinforced concrete columns with a rectangular cross section which were strengthened outside by using spiral hoops. And the research places on the respective behavior of the columns' longitudinal steel bar, the concrete and the exterior spiral reinforcement under vertical loads. Meanwhile the effects of the reinforcement capacities under different spiral distances mad eccentricities were compared.Through the comparison of load bearing capacities and deformation performance of the exterior strengthened and unstrengthened reinforced concrete columns, this paper analyzes the effects of the exterior spiral reinforcement method on the columns' ultimate load bearing capacities and the ductility. Offer the theoretical foundation for spiral hoops and strengthening technology to apply to the actual project, and through strengthening the comparison of the method with other independent columns, analyze various kinds of pluses and minuses of strengthening the method, offer basis on which adopt in the concreteproject.Study through the experiment of this text, obtain the main conclusion:I .With spiral hoops strengthen column can raise bearing capacity of column , the range raised increases as the ones that wind interval of spiral hoops are reduced. As spiral hoops interval 60mm , spiral hoops strengthen column raise for the unstrnethened column limit bearing capacity by 4%, as spiral hoops interval at the 40mm , limit bear the weight of strength raise 5.5% , spiral hoops interval 20mm, limit bears the weight of strength to improve by 9.5%.II .With spiral hoops strengthen column can raise transshape capacity of vertical reinforcement and concrete when the columns are destroying. It is 40mm as spiral hoops, transshape capacity of the vertical reinforcement has been improved by 18%, the transshape capacity of the concrete has been improved by 38%, as spiral hoops interval 20mm , transshape capacity of vertical reinforcement improve 78% , the transshape capacity of concrete raised 68%. So we can find out , the ductility of the column gets greater improvement.III. The exterior spiral reinforcement method is one of strengthen methods of modem , have construction to be effectual economy, in a situation that the size of component changes limitedly, the ability out of shape increases obviously, extending can improve a lot. So, have very wide popularization and application prospects.