Experimental Investigation of the Flexural Behavior of Geopolymer Concrete Beams with Different Reinforcement Schemes

: This paper presents an experimental study of the flexural behavior of geopolymer concrete beams reinforced with steel and Glass Fiber-Reinforced Polymers (GFRP) bars in addition to two types of fibers in the mixture: steel fibers and polypropylene fibers. Ten beams divided into three groups were cast and experimentally tested under four-point bending up to failure. Mid-span deflection, strain at reinforcement bars, and crack pattern of the examined beams were recorded and analyzed. The results showed that the crack width and deflection at failure were notably reduced by increasing the reinforcement ratio of GFRP bars and steel bars. Reinforced geopolymer concrete beams showed enhancement of flexural capacity than normal reinforced concrete beams. Geopolymer concrete beams reinforced with steel bars achieved increment for ultimate load and corresponding deflection by 8.78%, and 114.66% respectively than normal concrete beams. In addition, the ultimate load and deflection of geopolymer concrete beams reinforced by glass fiber polymer bars showed an increase of 1.54%, and 25.53% respectively to normal concrete beams. For geopolymer concrete beams reinforced by steel bars while the reinforcement ratio raises from 0.48% to 0.58%, the ultimate load improved by 34.25% and while the reinforcement ratio raises from 0.58% to 0.68% the ultimate load improved by 3.75%. The addition of steel or polypropylene fibers to the mix increased the failure load of GFRP-reinforced geopolymer concrete beams by 10.49% and 8.10%.