Evaluating the role of silica fume and Alccofine in concrete mechanical and durability strength using machine learning models

Cement manufacturing is a significant source of CO₂ emissions in the world, with approximately 8% of the global emissions being due to cement manufacturing, mainly through clinker manufacturing. In order to reduce its environmental effects, this paper examines the use of silica fume (SF) and Alccofine (AF) as additional cementitious materials (SCMs) to improve the mechanical and durability characteristics of concrete. The first stage involved the addition of SF at 5, 7.5 and 10% replacement levels to establish the optimum dosage and the second stage involved the addition of AF at 5, 10 and 15% with the optimum SF content maintained. Mechanical properties such as compressive strength, flexural strength, and split tensile strength and durability properties such as water sorptivity and rapid chloride penetrability (RCP) were tested. The best combination of 7.5% SF and 10% AF was 34.7% increase in compressive strength, 16.1% increase in flexural strength and 16% increase in split tensile strength over the control mix. This blend showed a 43.7% decrease in water sorptivity and a 42.8% decrease in RCP in terms of durability, which is significant in terms of resistance to water ingress and chloride penetration. Compressive strength was well predicted by machine learning models, with the most significant variables being cement content and AF. Life cycle assessment (LCA) indicated that the optimum blend had a global warming potential that was reduced by a factor of about 10% relative to OPC. These findings indicate that the integration of SF and AF does not only improve the performance of concrete but also minimizes its environmental impact, which is a promising avenue to sustainable and high-performance construction materials.