Relative Performance of FRP-Concrete-Steel Double Skin Tubular Columns versus Solid and Hollow Concrete-filled FRP Tubes

This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel composite columns. The results from twenty specimens including 12 double skin tubular columns (DSTCs), two solid concrete-filled fiber reinforced polymer (FRP) tubes (CFFTs), and six CFFTs with inner voids (H-CFFTs) are presented. The specimens were manufactured using high-strength concrete (HSC) and their FRP tubes were fabricated using unidirectional S-glass fiber sheets. The results of the experimental study indicate that that H-CFFTs perform significantly worse than DSTCs and CFFTs and their performance further degrades with an increase in the diameter of inner void. Comparison of the results from DSTC and CFFT specimens indicate that both hollow and concrete-filled DSTCs exhibit improved compressive behavior compared to CFFTs.