Influence of fly ash on concrete - A systematic review

Climate change is one of the most concerning issues existing. Carbon dioxide, which is a significant contributor to the greenhouse effect, is at the highest atmospheric levels ever recorded. The construction industry contributes to around 40% of carbon emissions produced all over the world. By consuming large amounts of non-renewable energy, the construction sector delivers infrastructure and buildings to society. This consumption consequently causes significant carbon dioxide emissions. The manufacture of cement contributes to greenhouse gasses both directly by producing carbon dioxide when calcium carbonate decomposes thermally, producing lime and carbon dioxide, and also by using electricity, especially from the combustion of fossil fuels. This paper focuses on studying the properties of fly ash and its impact on the characteristics and performance of concrete. Fly ash is a by-product that is obtained by the combustion of coal; thus, it is a waste product. The incorporation of this pozzolanic material which requires no manufacturing process like cement, as a replacement, contributes to sustainability by reducing the amount of cement used and also taking care of the disposal of fly-ash. (C) 2019 Elsevier Ltd. All rights reserved.