An experimental programme on 26 high-strength rectangular CFT columns subjected
to axial compression has been described. Favourable ductility performance was observed
for all specimens during the tests. A fibre model has been constructed to evaluate the nonlinear
axial load behaviour of the specimens. The comparison of load-shortening curves
shows that the model agrees very well with the tests. The comparison of failure loads
between the tests, design codes and the proposed model has also been presented. It
indicates that EC4 is unsafe to predict the ultimate capacity of CFT columns fabricated
from mild steel and high-strength concrete. On the other hand, ACI, AISC and the
proposed model conservatively estimate the failure loads of the specimens by 7, 8 and 2%,
respectively. Calibration of the proposed model against the present test data and those
reported in the literature suggests that it can be used to estimate the axial load capacity of
rectangular CFT columns with reasonable accuracy