Development of a novel cementitious blend derived from calcined pozzolanic materials and nanoparticles of self-compacting high-performance concrete

This research includes an experimental study of the potential use of pozzolanic and nanomaterials, including nano calcium carbonate (CC) and calcined clay (CK), throughout the manufacturing process of self-compacting high-performance concrete (SCHPC). Binary and ternary mix systems were prepared using 475 kg/m3 of cement and a fixed water-to-binder ratio (0.35). CK was used in proportions ranging from 6 to 24% of the total mass of cementitious materials. As for the ternary mixes, samples of (6% CK 1.5% CC, 12% CK 1.5 CC, 18% CK 1.5 CC, and 24% CK 1.5% CC) were prepared by partially replacing the weight of cement with CK and CC. The properties of the new SCHPC were assessed by slump flow (D (mm) and T500 (s)), V-funnel, L-box, and segregation resistance tests. Mechanical properties, including compressive and tensile strengths, were measured, and an ultrasonic pulse velocity test of the concrete was performed. Durability properties, including porosity and water absorption, were also measured. The findings demonstrated that adding calcined kaolin clay to concrete significantly improved its durability and mechanical properties. The best improvement was for binary and ternary mixtures at a 12% replacement ratio of calcined kaolin clay, where compressive strength improved by 20.9% and porosity and water absorption decreased by 15.6% and 19.9%, at 56 days compared to the reference mixture. The ternary mixtures also improved better than the ternary mixtures for the same replacement ratios of calcined kaolin clay for all ages. For example, the 12CK1.5CC mixture recorded a 25.5% improvement in compressive strength and a 21.3% and 40.8% reduction in porosity and water absorption compared to the reference mixture at the age of 56 days. This study accomplished its goals by sustainably producing eco-friendly concrete through the reduction of cement content via pozzolanic and nanoparticles.