Mechanical properties of axially and eccentrically loaded CFRP–coral concrete columns

Bearing capacity tests were carried out on axially and eccentrically loaded coral concrete short columns reinforced with carbon-fibre-reinforced polymer (CFRP) bars. Parameters such as the ultimate bearing capacities and the stress in the CFRP bars and surface concrete were measured and analysed. All the columns failed due to the crushing of concrete in the compression zone. An increase in eccentricity not only decreased the ultimate bearing capacity, but also resulted in the shear fracture of CFRP longitudinal bars in the compression zone. In general, the stress of the longitudinal CFRP reinforcements in all specimens was quite low. The maximum stress of the CFRP bars in the columns was 105.78 MPa, just 23.5% of the ultimate compressive strength of the CFRP reinforcement. The superior bond between the CFRP bars and coral concrete conformed to the deformation coordination. A calculation method for the bearing capacity of CFRP-reinforced coral concrete short columns was developed and the calculated results were found to agree well with the test results.