Experimental and theoretical investigation on seismic performance of Seawater Sea sand cementitious columns reinforced with <scp>GFRP</scp> bars and <scp>PVA</scp> fibers

Abstract With the shortage of global freshwater resources and the improvement of seismic requirements in coastal areas, this study investigated the seismic performance of seven seawater sea sand cement‐based composite columns (GC) with glass fiber‐reinforced polymer bars under different parameters. The effects of polyvinyl alcohol (PVA) fiber content, axial compression ratio, cement‐based composite strength grade and stirrup spacing on the bearing capacity, energy dissipation capacity, and ductility of the specimens were analyzed. The experimental results show that the cumulative energy consumption of the specimens with 2% PVA fiber is about 35% higher than that of the specimens without fiber. When the axial compression ratio decreases from 0.4 to 0.2, the comprehensive performance of the specimen can be improved by up to 43%. When the cement‐based strength grade is increased from C30 to C50, the bearing capacity of the specimen is significantly increased, with a maximum increase of 22%. In addition, the restoring force model theory of composite column is established, and the skeleton curve is consistent with the test curve. The modified damage model is established, and the damage assessment of each specimen is carried out. It is found that the low axial compression ratio and the incorporation of PVA fiber are helpful to slow down the damage and failure of the specimen.