Compression behavior of CFRP–confined coral aggregate concrete (CCAC) circular stub columns

Carbon fiber–reinforced polymers (CFRPs) have excellent tensile strength and great resistance to chloride ion corrosion. In the 21st century of rapid development in marine construction, the composite structure of CFRP and coral aggregate concrete (CAC) has broad development prospects and great research value. This paper proposes a CFRP–confined coral aggregate concrete (CCAC) column as a novel composite column suitable for use in marine environments. Eighteen CCAC circular stub columns were constructed, and compression tests were carried out under axial and eccentric loads. The compression behavior, including the load–carrying capacity, stress–strain relationship, and ductility of CCAC stub columns was investigated. Test results show that the CFRP sheets greatly improve the load–carrying capacity and ductility of the CAC stub columns. Among the three influencing factors, the influence on the load–carrying capacity and ductility of the CCAC stub columns is eccentric distance, the number of CFRP layers, and the CAC strength in descending order. Finally, the load–carrying capacity calculation method and the stress–strain relationship of CCAC stub columns under axial compression were established, and an eccentric reduction coefficient was proposed to calculate the load–carrying capacity of CCAC columns under different eccentric distances.