Flexural Response and Moment Redistribution of RC Continuous T-Beams Strengthened With FRP or Steel Bars

This paper is an experimental study to investigate the behavior of the RC continuous T-beams
strengthened with NSM CFRP or steel bars under static loads. The experimental program
consists of five RC continuous T-beams with overall dimensions equal to (200*300*4300) mm
and with constant load (120kN) at the central loaded column. The first one was unstrengthened
control beam designed to fail in flexure. Two beams were strengthened at the hogging region
by using CFRP or steel bars, the other beams were strengthened at the mid-span region. The
effect of strengthening material type and region on the load carrying capacity of the beams,
deformation, ductility index and moment redistribution were investigated. Test results revealed
that, three failure modes of beams were observed, namely the steel yielding, crushing of the
concrete after steel yielding, end anchorage separation before the steel yielding at the
strengthening region. The ductility of all strengthened beams was reduced compared with that
of the respective unstrengthened control beam. The moment redistribution ratio depends deeply
on the internal force at the main sagging reinforcement