Performance of high volume fly ash concrete incorporating additives: A systematic literature review

Fly ash is commonly used as a partial cement replacement material, but this is limited to replacement levels of 30% or less, with significant quantities of fly ash still not utilized globally. There has been significant recent research into High Volume Fly Ash (HVFA) concrete to enable the utilization of fly ash and to reduce CO2 emission by reducing cement demand. This comprehensive review summarizes up to date literature on HVFA concrete with more than 50% of cement replacement using ASTM Class F low calcium fly ash. Firstly, the available HVFA literature in which only fly has been used to replace cement, is categorized based on the replacement level and the mechanical and durability property results are summarized. Secondly, the remaining literature is categorized based on the different material additions to modify the HVFA concrete and the results are compared. The summarized results are discussed to elucidate the mechanisms underlying the reported results. The effect of each material addition on the HVFA concrete properties are also discussed to identify potentially more suitable additives for future development. Overall, this paper will provide an understanding of the current state of HVFA concrete research and the gaps in research for the development HVFA concrete containing higher replacement levels and achieving the required performance. Hence, summarised knowledge would significantly be beneficial to design prospective research towards a sustainable cement-free concrete using industrial waste.