A review on developments of environmentally friendly geopolymer technology

This study aims to present an overview of the progress of geopolymer composites with regards to the latest developments on its constituents (binders, activators, and aggregates) and manufacturing techniques. Some ecological, economic, and industrial limitations of the traditional aluminosilicate binders yield to the pursuit of alternative ones over the period. Some of these latest binders e.g. ferrochrome ash, mine tailings, rice husk ash, red mud, have been highlighted in this paper. Current advances on replacement of natural fine and coarse aggregates such as mine tailings (iron ore tailings), recycled/lightweight aggregates for geopolymer preparation have been reviewed from the past literature. The paper also focuses on developments regarding the new class of green alkaline and acidic activators, which is traditionally considered to be the binding agent in the preparation of geopolymer composites. Different geopolymer production methods have been briefly discussed to study their effectiveness in achieving a strong and durable composite. This paper may serve to encourage further experimental research works for achieving more sustainable, cost-effective geopolymer composites with enhanced mechanical properties.