Utilisation of supplementary cementitious materials from agricultural wastes: a review

This paper presents a critical literature review on the use of supplementary cementitious materials (SCMs) from agricultural wastes (mainly from crop residues) in cementitious systems. The current utilisation of these materials as partial replacement of Portland cement is reviewed with respect to the influence of the materials' characteristics on the performance and the limit of replacement in cementitious systems. In spite of the benefits of SCMs from agricultural wastes (such as rice husk ash, palm oil fuel ash and sugarcane bagasse ash), their unavailability in the required form, heterogeneous nature and insufficient data make it difficult to generalise their performance. Therefore, a review of the existing information available will help to unravel areas of further research, any relationship between the influence of the processing method and materials characteristics on the limit of replacement and performance in cementitious systems and assist in their standardisation and sustainable utilisation. This, coupled with the reproducibility of results, will assist the processing and adoption of other agricultural wastes in cementitious systems.