Palm oil fuel ash as a sustainable supplementary cementitious material for concrete: A state-of-the-art review

New progress in recycling processes has resulted in the conversion of non-renewable materials to partially renewable resources. in this regard, the role of employing supplementary cement-based ‎materials in the concrete is significant to avoid excessive waste ending in landfills. There ‎are ‎numerous by products and wastes of have an immense value in the production of environmentally friendly concrete. In terms of application, the literature has highlighted the enormous potential of palm-oil fuel ash (PFA) as an alternative material in green concrete. PFA has been frequently used in the substitution of cement in concrete production to minimize the cost, health risk, energy consumption, and environmental degradation associated with cement production. Moreover, recycling by products and wastes aid in alleviating issues related to waste material disposal. The goal of this paper is to offer a state-of-the-art review of the published academic studies on the use of PFA in concrete and its impact on the workability, compressive strength (CS), splitting tensile strength (STS), and durability of concrete. Also, this paper aims to investigate the effect of PFA on sustainability by a scanning electron microscope (SEM) analysis of the micro-structure of concrete. The results indicate that using PFA with partial substitution improves workability and CS while decreasing STS and water absorption (WA). Furthermore, this study underscores the need for future research developments in this field.