Enhancing the performance of mortar with two pozzolanic materials: Silica fume and basalt powder

This study examined the effects of incorporating two pozzolanic materials, viz., silica fume (SF) and basalt powder (BS), on the mechanical and durability properties of mortars, with a specific focus on compressive strength, porosity, chloride penetration, chloride diffusion coefficient, and reinforcement corrosion resistance. Ordinary Portland Cement Type I (OPC) was partially replaced with a fixed proportion of 10% SF, combined with BS contents of 10%, 15%, 20%, 25%, and 30% by weight of binders. A water-to-binder (W/B) ratio of 0.48 was maintained, and a superplasticizer (SP) was incorporated to ensure adequate workability. The inclusion of BS and SF necessitated additional superplasticizer to maintain flowability, highlighting the influence of fine particle size and increased surface area on the rheological properties of the mixtures. Test results at 28 and 90 days demonstrated that mortars containing 10% SF with either 10% or 15% BS outperformed the control mortar (CT) and other mixtures, exhibiting superior compressive strength, low porosity, and enhanced resistance to chloride ingress and reinforcement corrosion. Strength and durability enhancements were more pronounced at later ages, emphasizing the long-term benefits of pozzolanic reactions in refining the mortar microstructure. Furthermore, a mathematical model was proposed to facilitate a comprehensive understanding and prediction of compressive strength in the ternary binder systems (OPC, SF, and BS), offering valuable insights for optimizing sustainable cementitious materials in construction applications. • Basalt powder (BS) and silica fume (SF) were used to replace cement. • Ternary binder system of BS, SF and OPC improved the properties of mortar. • Mathematical model was proposed to facilitate a comprehensive understanding and prediction of compressive strength in the ternary binder systems (OPC, SF, and BS). • Compressive strength, porosity, chloride penetration, chloride diffusion coefficient, and reinforcement corrosion resistance of mortar were improved.