Cyclic Axial Compression Behavior of FRP-Confined Seawater Sea-Sand Concrete-Filled Stainless Steel Tube Stub Columns

Concrete-filled steel tube (CFST) columns have been widely used in onshore constructions. To extend its applications to coastal/offshore structures and meanwhile relieve the overexploitation on freshwater river sand, an FRP-confined seawater sea-sand concrete-filled stainless (F-SSCFSST) column is proposed. The cyclic axial compressive behavior of this newly proposed was investigated study. A total 22 specimens (including nine pairs for compression four individual monotonic compression) were tested. Most importantly, influences three loading patterns (i.e., single full unloading/reloading, repeated mixed partial unloading/reloading) studied. results showed that although all F-SSCFSST failed from FRP rupture mid-height area, less fierce with internal unloading/reloading cycles. Similar concrete, envelope curve load–strain response matched closely a particular specimen. However, unloading curly compared typical concrete. confinement effect provided by jacket much stronger than tube. Although Lam Teng’s model, which could provide satisfactory estimations strain recovery ratios stress deterioration ratios, it underestimated plastic strains 20%.