Shear behavior of fly ash-based geopolymer R/C beam with bauxites as coarse aggregates: Experimental program

Abstract

Some regions in Indonesia have bauxite materials but difficult to find gravel stone for coarse aggregates. Strength behavior of fly ash-based reinforced concrete beam with bauxite material as coarse aggregates was very important to investigated before applying in the real project. Two beams were tested in this study. The first beam was normal reinforced concrete beams as a reference beam. The second beam was fly ash-based geopolymer reinforced concrete beam with bauxite as coarse aggregates. The beams had the section of (120 mm × 240 mm) and simple support with span of 3000 mm. Two points loading was applied to the beam to investigate the shear behavior. The beam specimens were tested under load control. A transfer beam was used to transfer the load from the actuator to the beam. The experimental result showed that the normal reinforced concrete beam and the fly ash-based geopolymer reinforced concrete beam with bauxite as coarse aggregates were fail in shear failure. The normal reinforced concrete beam was failure in brittle manner, while the fly ash-based geopolymer reinforced concrete beam was more ductile than the normal reinforced concrete beam. The maximum load-carrying capacity of normal reinforced concrete beam was 14.30 kN with maximum deflection was 23.78 mm. While the fly ash-based geopolymer concrete with bauxite as coarse aggregates reached the maximum load-carrying capacity 14.45 kN with maximum the deflection was 49.49 mm. Comparing the shear strength based on the theory and experimental result showed that the experimental result was lower than the theory.