FLEXURAL BEHAVIOR OF FLY ASH-BASED GEOPOLYMER R/C BEAM WITH BAUXITE MATERIAL AS COARSE AGGREGATES

Abstract

Bauxite materials are provided in Indonesia especially in Batam Island. Based on the previous
research, this material can be used as coarse aggregates in fly ash-based geopolymer concrete. To study the
behavior of fly ash-based geopolymer reinforced concrete beam subjected to bending, this research is
conducted. Two fly ash-based geopolymer reinforced concrete beams were made and tested. The first beam
was made from normal concrete as a reference beam, while the second beam was fly ash-based geopolymer
concrete which was using bauxite as coarse aggregates. Both beams had the same size of 120 mm width and
240 mm in height. Two longitudinal reinforcements with a diameter of 16 mm as tensile reinforcements and a
diameter of 13 mm as compressive reinforcements. The stirrups using diameter 6 mm with spacing 100 mm
along the span of the beam. Two loading points were applied to the beam using monotonic loading. The
beam is a simple beam. The load-carrying capacity of the normal beam and fly ash-based geopolymer
concrete beam were compared. Section analysis was also conducted to check the experimental program with
the theory. The result shows that the flexural behavior of both beams was similar. Both beams show as
ductile beams. The maximum load of the normal concrete beam was 63.00 kN. While the maximum load of
the fly ash-based geopolymer concrete was 66.15 kN. The section analysis of both beams closed to the
experimental result indicated that the theory can be applied to the fly ash-based geopolymer concrete with
bauxite material as coarse aggregates.