Structural Behaviour of Geopolymer Concrete Beams Reinforced with Bamboo Bars

Global warming has become a serious environmental problem. A major cause of global warming is CO ₂ , of which the construction industry emits large amounts from to the manufacture of cement and steel. Therefore, research and development on bamboo-reinforced concrete, which does not contain steel or cement, has increased in recent years. Geopolymer concrete, a type of concrete that does not use cement, is being researched as an alternative material to conventional cement concrete. However, many problems remain to be solved, and little research has been done on bamboo reinforcement and geopolymer concrete. In this study, to explore the feasibility of crafting a structure of cement-free geopolymer concrete with bamboo reinforcement, a beam-shaped sample was fabricated, on which a flexural test was conducted. The experimental results clarified the following: 1) A prototype geopolymer concrete was produced using glass powder as a binder. As a result, the geopolymer concrete was crafted with a setting time of 2 hours or more and a compressive strength of 15 N/mm ² or more at a material age of 28 days. 2) In a flexural test of geopolymer concrete beams with bamboo reinforcements, the main bamboo reinforcements slipped early due to low bond strength, resulting in poor crack dispersion. 3) The experimental results can be used to accurately evaluate the strength of a beam test sample via values calculated by existing reinforced concrete design formulas. In bamboo-reinforced concrete beams, it is necessary to evaluate the strength by considering the bond strength.