This research presents an experimental study to examine the flexural behavior of steel cold-formed I-beam with
strengthened hollow tubular flanges. Nineteen of cold-formed steel I-beam with hollow tubular flanges were
prepared and experimentally tested on four-point bending tests. One of these specimens was not strengthened,
which used as a control specimen, and eighteen specimens were strengthened with filling the tubular flanges by
different materials. Twelve specimens were strengthened at the compression hollow tubular flanges only, with
and without shear connectors. Finally, six specimens were strengthened at the compression and tension hollow
tubular flanges. The strengthened materials used are different types of wood wastes (Particleboard Wood-
Sawdust with cement mortar- Sawdust with epoxy- Sawdust with polyester), light weight concrete, and polymermortar.
All specimens were loaded by two vertical loads to failure. Specimens’ mode of failure and vertical
displacements were recorded. Vertical load-deflection at mid-span relationships have been analyzed to study the
effect of strengthened materials. It was observed that maximum capacity was achieved by using polymer-mortar
rather than the other materials. Using shear studs and strengthened compression and tension flanges did not
show an obvious effect on the ultimate load of the tested specimens compared to those that were strengthened
the compression flanges only. For all the strengthened specimens, improving in the load-mid span deflection
relationships were achieved compared with the control specimen. The bending moment capacities were
compared with the expected values using the Egyptian Code of Practice for Steel Construction (LRFD), which
indicates that the design method of this code is conservative in comparison to the experimental test results, but it
is not conservative in expected the moment capacities of strengthened specimens that used the Sawdust with
cement mortar and light weight concrete materials. |
