Figure 3.

Experimental tests on CFST columns: (a) typical test setup and instrumentations (linear varying displacement transducers and strain gages were used to record the variations of displacement and strains) (represented with permission from Du et al. [55]), (b) local outward buckling of steel tube (represented with permission from Du et al. [55]), (c) overall buckling failure of slender column (represented with permission from Du et al. [55]), and (d) damage of concrete core (represented with permission from Lyu et al. [61]).