Eco-friendly agro-waste based geopolymer-concrete: a systematic review

Abstract

Abstract Numerous scientific studies have been conducted, and a wide range of new inorganic geopolymer composite applications have emerged as a result. This innovative material can be made from agricultural waste sources rich in aluminosilicate, which provides best substitute for traditional cement in terms of both quality and cost. This paper presents the state-of-the-art review of deploying agro-wastes as precursor for geopolymer concrete with the view to aggregating the research studies of using agro waste ash-based geopolymer as the most auspicious, durable, inexpensive, user-friendly, and eco-beneficial construction materials for the long-term use. This paper thoroughly examines the rheological, workability, chemistry, and mechanical characteristics of agro-waste ash-based geopolymer concrete with emphasis on sugarcane bagasse and banana peels ash. Sugarcane and green bananas (matooke) play vital roles in East African agriculture, economy and food security. The effects micro-structures, curing conditions, molarity of metallic alkalis, proportioning of alkaline-binder ratio, aggregates content and size fractions effects on the behavior of geopolymer concrete were critically assessed. The study highlighted the abundance of these agro products which serve as staple food in East African region, therefore, it becomes imperative to recycle its waste to produce durable concrete by way of waste management strategy. As a vital component of the readily available building materials, they have a crucial role to play in providing the construction sector with a sustainable outlook while concluding that agro-wastes are potential material that could be a game changer for geopolymer concrete, a number of research gaps that worthy for further study were identified. The findings of this review further demonstrates that agro-waste derivatives when used as binder materials in geopolymer concrete can be a viable and sustainable alternative to conventional cementitious materials.

Keywords

• Geopolymer composites
• Agro-wastes based concrete
• Alkali activated binder
• Banana peel ash
• Bagasse ash