Towards eco-friendly cement-based materials: a review on incorporating oil shale ash

Abstract

AbstractConsidering the growing environmental concerns associated with construction industry activities, this article reviews the potential use of oil shale ash (OSA) as a cement substitute in cementitious materials. Specific issues to be investigated include the ideal OSA content to be incorporated into the mix, the optimum oil shale (OS) burning temperature for obtaining the ash, the influence of the specific area and chemical composition of the OSA on the composites, as well as the effects of its addition on the fresh state, mechanical and durability properties. To this end, the ProKnow-C systematic literature review process was adopted for the first time to study this topic, resulting in a portfolio of 14 manuscripts associated with the questions to be analyzed. The primary outcomes include: OSA contents between 10 and 30% are suitable for replacing cement; the ideal burning temperature for OS is between 600 and 800 ºC; high specific areas (between 6000 and 8000 cm2/g) improve pozzolanic activity; high OSA contents may require the use of water-reducing additives to improve workability; incorporating OSA into Portland cement-based materials can improve their compressive strength and durability. These conclusions highlight the importance of understanding the effects of incorporating OSA in developing cementitious materials, providing a basis for future research.