Research trends on high volume fly ash (HVFA) binders’ strength and durability: a global bibliometric and visualisation analysis

Fly ash (FA) from Eskom coal-fired power stations in South Africa is readily available. It is produced in more than 30 million tonnes annually. It presents a huge waste handling challenge and an opportunity for South Africa to offset it carbon emissions by developing and using Ultra High-Volume Fly Ash binders with FA content > 70%. The current study analyses peer-reviewed research articles on HVFA binders’ strength and durability using cooccurrence and bibliographic coupling of authors, institutions, countries, journals, and keywords using Covidence, Bibliometrix, and VOS viewer. Findings reveal that research efforts toward increasing fly ash dosages in HVFA binders remain significantly limited below 70%. HVFA binder strength and durability research depends on a nation’s coal consumption level and fly ash availability. Leading global coal consumers are also leading nations in HVFA binders’ research. Although South Africa is among the leading coal consumers and carbon emitters, it is ranked the least among nations contributing to developing high-strength and durability HVFA binders. The lack of research on HVFA binder strength and durability in South Africa calls for urgent scholarly efforts, given that findings from other nations and power plants cannot be generalised due to wide variations in fly ash characteristics within the same classes. The variations within same fly ash classes calls for further research to develop classification systems for HVFA binders’ development. Compressive strength and shrinkage were identified as the predominant properties of interest. The findings suggest that higher dosages of fly ash (FA) tend to reduce shrinkage. However, there are exceptions challenging this trend, underscoring the need for further research to address inconsistencies.