ABSTRACT
CFST members are subjected to bending in applications such as horizontal beam
and columns in portal frame structures. The behaviour of CFST beams is similar to
that of unfilled tubular beams described in Zhao et al. (2005). A summary of
experimental studies on CFST beams is given in Table 3.1. An increase in moment
capacity due to concrete filling is obvious as shown in Figure 3.1 for CFST RHS
where the percentage of increase depends on the strength of the filler material. For
CFST CHS the measured increase was 21% for normal strength concrete with f
of
24MPa (Elchalakani et al. 2001). The increase in ductility because of infill
concrete can be seen from Figure 1.10(b), which is independent of the filler
material strength. Concrete-filled fibre reinforced polymer tubes in bending was
recently studied by Fam and Rizkalla (2002), and Fam and Son (2008).
