Composition, Structure and Properties of Geopolymer Concrete Dispersedly Reinforced with Sisal Fiber

The application of geopolymer composites in the construction of environmentally sustainable buildings and low-carbon structures has generated considerable interest, presenting an alternative and eco-friendly approach to composite materials. The purpose of this research is to develop a new composition of geopolymer concrete, dispersedly reinforced with sisal fiber, and investigate its structure and physical and mechanical properties. To evaluate the effectiveness of the proposed compositions, the fresh properties of the geopolymer concrete mixture—density and slump—and the properties of the hardened composite, namely, the compressive strength, flexural strength and water absorption, were studied. The most rational composition of the alkaline activator was established, and sisal fiber (SF) was protected from alkaline degradation by adding styrene-acrylic copolymer at an amount of 5% and microsilica at an amount of 3% to the concrete mixture. It was determined that the most optimal SF content was 1.0%. The compressive strength exhibited a maximum increase of 12.8%, the flexural strength showed a significant increase of 76.5%, and the water absorption displayed a decrease of 10.3%. The geopolymer fiber-reinforced concrete developed in this study is an environmentally friendly replacement for traditional types of concrete with cement binders and can be used for the manufacture of small architectural forms and landscaping elements.