Compression behavior of FRP bars/coral concrete columns under axial compression loading

Abstract

The axially loaded bearing capacity tests on 8 fiber reinforced polymer (FRP) bar/coral concrete columns and 1 steel bar/coral concrete column were carried out. Parameters such as reinforcement ratio, stirrup spacing, slenderness ratio and reinforcement type were discussed. The results show that the failure mechanism of FRP reinforced coral concrete column and steel bar/coral concrete column is different, but the mechanical performance is still good. Increasing the diameter of longitudinal reinforcement leads to the decrease of bonding performance between longitudinal reinforcement and concrete protective layer. Reducing the spacing of stirrups is beneficial to improve the ductility of the members, and the higher the aspect ratio, the lower the bearing capacity of the members. Then, based on the data analysis of the compression performance experiment and the comparison of references, it is suggested that the nominal yield strength of carbon fiber reinforced polymer (CFRP) reinforcement should be 0.34fy (fy is the ultimate compressive strength of the reinforcement), and the corresponding theoretical value is similar to the experimental results. Finally, the theoretical calculation formula for bearing capacity of CFRP/coral concrete axial compression column is put forward, which provides a reference for engineering practice.