Flexural behavior of hollow self compacted mortar ferrocement beam reinforced by GFRP bars

Abstract

This study aimed to investigate a form of ferrocement that was a hollow ferrocement beam of self-compacting mortar reinforced with various types of metallic (steel bars, steel wire mesh) and non-metallic (GFRP bars, fiber glass mesh) reinforcement. The experimental program comprised casting twenty ferrocement beams with dimensions of 150 × 225 × 2000 mm, incorporating 50 mm of ferrocement thickness and a polystyrene cork core of 50 × 125 mm. The results showed that the hollow ferrocement beams reinforced with GFRP bars and several layers of the fiber glass mesh (one, two and three) gave higher loads by 7.51%, 9.88% and 5.15%, respectively, as well as higher energy by 4.75%, 27% and 15.10%, respectively, However, the ductility of these beams was reduced by 37.84%, 37.33%, and 44.27%, when compared to beams reinforced with steel bars and several layers of steel wire mesh (one, two and three). These beams gave lower first crack loads, high deflections, and wide cracks with no control on crack width compared to beams reinforced with steel. The increasing number of the welded wire mesh and fiber glass mesh layers increases the first crack load, ultimate load, and energy absorption by 20%, 30.25% and 69.2%, respectively, in the ferrocement beams reinforced with (steel bars and steel wire mesh) and 34.36%, 27.1% and 94.92% respectively, in the ferrocement beams reinforced with (GFRB bars and fiber glass mesh) when three layers of mesh were used compared to beams reinforced with bars only without mesh. Also, the study shows that steel wire mesh and fiber glass mesh materials were better at controlling crack width than beams reinforced with bars only without wire mesh. The results showed that the theoretical calculations based on strain and force distribution assumptions that the theoretical and experimental ultimate loads of the beams reinforced with steel were acceptable, with a ratio ranging from 0.98 to 1.12. But, in the beams reinforced with GFRP, the theoretical and experimental ultimate loads of the beams were varied and spaced clearly with a ratio that ranged from 0.82 to 1.36. The study showed that the hollow ferrocement beams reinforced with steel bars and steel wire mesh layers were more efficient than beams reinforced with GFRP bars and fiber glass mesh.