This paper presents results of an experimental study on the flexural behavior of a new type of
composite beam. This innovative type of beam was composed of glass fiber reinforced polymer
(GFRP) I-beam, tension steel (or GFRP) bars and steel stirrups. Three beam specimens were cast and
tested including one conventional reinforced concrete beam and two composite beams. All the beam
specimens had the same cross-section dimension of 200 mm × 350 mm and the same length of 2040
mm. The parameters investigated in this study included two types of tensile longitudinal bars. The
beam specimens were tested under four-point bending. The test results show that the composite beam reinforced with I-beam and tension steel bars exhibited a higher flexural strength and ductility than the conventional reinforced concrete beam, and the ultimate load of this specimen was controlled by the GFRP I-beam. The performance of the composite beam reinforced with I-beam and GFRP bars was poor both in the ultimate load and the ductility, and the brittle failure mode was caused by the rupture of the GFRP bars.