Spiral Stirrups-PVC Pipe Experimental Study On The Performance Of Reinforced Concrete Short Columns Axial Compression

With the development of building structure system, reinforced concrete structure of section size, since big, construction convenient, low bearing capacity of disadvantages increasingly prominent, need to improve and perfect, to adapt to the requirement of modern structure. Emergence and development of confined concrete, for the development of the reinforced concrete structure provides a good theoretical basis. In this paper, Spiral stirrups-PVC pipes (Spiral stirrups-PVC pipes, hereinafter referred to as the SS-PVC pipes) the new type of composite structure of reinforced concrete column, using the principle of confined concrete, the Spiral stirrups and PVC tubes composite constraint on the column, improve the bearing capacity of the reinforced concrete column. This new type of composite structure with the method of composite material constraint, give full play to the advantages of steel and plastic material, which can improve the bearing capacity of the reinforced concrete column, and economical and practical, for reinforced concrete structure puts forward a new direction of development, has a lot of research and application value.This article through to 32 reinforced concrete short columns axial compression test, the reinforced concrete column, PVC pipe reinforced concrete column, SS-PVC tube reinforced concrete column, with longitudinal reinforcement SS-PVC pipes (hereinafter referred to as the SSR-PVC pipes) the bearing capacity of reinforced concrete column were analyzed, estimate the SS-PVC pipe enhanced effect of bearing capacity of reinforced concrete column size, analysis of longitudinal reinforcement diameter, core area ratio, stirrup spacing and diameter of stirrup etc. The influence of the enhanced effect of factors on the bearing capacity. And, according to the existing bearing capacity calculation model of confined concrete, determine the PVC tube reinforced concrete column, the SS-PVC tube of the bearing capacity of reinforced concrete column calculating model, provide a reference for further research. Research results are as follows:(1) PVC pipe constraint on the bearing capacity and ductility of the reinforced concrete column has improved, but the effect was not significant, need further improvement.(2) SS-PVC pipe constraint on the bearing capacity and ductility of the reinforced concrete column has a larger increase, core area ratio, stirrup spacing and diameter of the bearing capacity of great influence.(3) the SSR-PVC pipe constraint of the bearing capacity of reinforced concrete column with core longitudinal reinforcement before improving effect is not big, and, with longitudinal reinforcement can weaken the effect of restraint.(4) according to the existing concrete filled steel tubular columns, stirrups of confined concrete columns bearing capacity calculation model, calculate the SS-PVC tube of the bearing capacity of reinforced concrete column calculating model, and then compare the bearing capacity experimental values and calculated values. Through comparison and analysis, test of normal section column limit load calculated values and measured values is relatively close, the errors are within 15%.