Experimental Study On BFRP-PVC Confined Reinforced Self-compacting Recycled Concrete Short-column Under Axial Compression

BFRP-PVC confined reinforced self-compacting recycled concrete column is a new kind of composite member, which is winding FRP strips on the outside of PVC tube, then putting the reinforcement cage and pouring self-compacting recycled concrete in the PVC tube. The composite component has not only the advantages of PVC tube corrosion resistance, but give full play to the constraints of the core concrete. Based on experimental study and theoretical analysis, the mechanical behavior of BFRP-PVC confined reinforced self-compacting recycled concrete short column under axial compression is researched, the main contents and results are as follows:(1) According to the difference of reinforcement ratio, the test specimens are divided into three groups, a total of 30 BFRP-PVC confined reinforced self-compacting recycled concrete columns are designed. The paper describes the mixing process of self-compacting recycled concrete and the process of manufacture and the loading scheme of these columns.(2) The test of BFRP-PVC confined reinforced self-compacting recycled concrete short columns under axial load, Study the BFRP constraint mechanism of core concrete and the stress-strain relationship. Experimental study shows that the stress-strain relationship of the BFRP- PVC confined reinforced self-compacting recycled concrete short column under axial load may be divided into three phases: elastic phase; transition phase and failure phase.(3) Study found that the BFRP banding spacing and reinforcement ratio have effect on the axis compression behavior of BFRP-PVC confined reinforced self-compacting recycled concrete short column. Test result indicates that strength enhancement decreases with the increases of BFRP spacing, and specimens of different spacing manifested same trend between the ultimate bearing capacity and reinforcement ratio. Group of high steel ratio develop lower Core strength enhancement than group of low steel ratio. The relationship between bearing capacity and reinforcement ratio is approximately a line.(4) Based on the bearing capacity calculation formula of existing reinforced concrete filled steel tubular and FRP-PVC concrete column, comprehensively analysis Longitudinal bar and stirrup constraint effect on the ultimate bearing capacity, put forward the ultimat bearing capacity calculation formula of BFRP-PVC confined reinforced self-compacting recycled concrete column.