Sustainability Potentials of the Precast Industry in Kenya

Abstract Kenya is overly affected by the consequences of climate change and struggling to find ways to balance mitigation with the urgent need to meet the country’s infrastructure and housing needs. Traditional concreting methods, such as onsite mixing and manual compaction, are slow, material, water, and labor-intensive. The precast industry therefore offers a competitive alternative in terms of cost and environmental impact. When ordinary Portland cement is used, it is responsible for 80–90% of the carbon footprint of concrete. Hence, there is urgent need to minimize carbon emissions by using supplementary cementitious materials (SCMs) in concrete construction. Since cement factories are mostly located around the city of Nairobi, in other regions, the price of cement increases with transport distance. Precast concrete construction could become a lever for both lower prices and carbon emissions. Clinker reduction can take place at the cement plant or concrete mixing plant. Blending in the cement factory can produce more robust binder qualities but is limited to large SCM supply streams. Blending at the precast plant allows for tailored, smaller, local supply streams from industrial and agricultural by-products. The paper discusses the potential of using artificial intelligence to merge multiple small heterogeneous feed streams from renewable and recyclable resources into large homogeneous feed streams, with a particular focus on the use in precast concrete processing.