A Review of Life Cycle Assessment (LCA) for Evaluating Environmental Impacts of Geopolymer Concrete

Concrete is the most commonly used material in the construction industry after water because of its special properties. However, the production process of Portland cement has major environmental drawbacks, as it is responsible for 8% of global CO2 emissions (4 billion tons per year). Therefore, it seems necessary to use an alternative to conventional cements (Portland). In recent years, geopolymer has been introduced as a new and environmentally friendly cement agent to replace Portland cement. Geopolymers are chains or networks of mineral molecules linked by covalent bonds and consist of a combination of two main components, the aluminosilicate source (secondary raw material) and the alkaline activating solution. They can have excellent technical properties such as high mechanical strength, good chemical resistance or high thermal resistance. The fact that the good performance of geopolymers can also be achieved by using secondary raw materials such as industrial waste including fly ash or slag has been proven by various studies. This shows the great attention given to this technology. The use of waste to produce geopolymers can not only solve the problem of waste disposal, but also reduce the consumption of secondary raw materials. However, there is limited knowledge about the environmental consequences of geopolymer production. In this paper, an overview of the impacts of geopolymer production from an ecological perspective is presented. In addition, the drivers of the ecological impact of geopolymers are discussed to provide guidance for the development of geopolymer compounds for diverse applications.