Mapping and synthesizing the viability of cement replacement materials via a systematic review and meta-analysis

Abstract

Supplementary cementitious materials (SCM) are alternative to the conventional cement and have been studied by so many authors owing to the high carbon content of cement. The use of SCM is significant in addressing challenges of carbon emission and its impact on the 2050 carbon reduction RoadMap. Available studies shows that SCM obtained from both industrial and agricultural wastes presents significant variability in performance as cement dosage in concrete increases. The first aim of this study is to map and synthesize the available evidence from literatures to support this variability. The second objective is to provide statistical evidence from available literatures of certain SCM that enhance the structural performance of low carbon concrete in terms of compressive strength. From the results, trend of findings from literatures on the use of SCM shows a surge in research for cement replacement occurring over the last decade with optimal performance for industrial waste SCM shown to be limiting at 40% cement replacement while that from agricultural waste occurs at 10% cement replacement. Data were sourced from Scopus database and selected from peer review journals of both primary and secondary studies on cement replacement materials. 728 published articles were obtained from the search using four strings namely,’Recent cement* replacement and cementitious materials’’, ‘’Recent supplementary cementitious materials’, ‘’Eco-friendly and cementitious materials’’ and ‘’Low carbon intensive cement replacement materials’. Meta-analysis is carried out on the selected articles having quantitative data to synthesise some of the result of the published articles to examine the impact of Ground granular base slag and Pulverized Fuel Ash cement on concrete strength development as cement replacement. It is shown that Ground granular base slag, Pulverized Fuel Ash and Metakaolin improve and enhance the eco friendliness of the concrete. From the results, optimal percentage of cement replacement is a gap which remains unresolved due to mineralogy and reactivity of the SCMs and would provide the solution for the desired green concrete optimization. It is shown with statistical evidence from meta-analysis that ground granular base slag and Pulverised fuel ash decreases the effect of low compressive strength by at least 2% to about 75% which is considered in our opinion as effective to enhance the sustainability of concrete.