Research of Physical and Mechanical Properties of Self-Compacting Concrete Based on Polyfractional Binder

This article presents the results of a study on the influence of a three-level dispersed composition of the clinker component of a binder, which includes coarse, medium, and fine fractions, on the physical and mechanical properties of self-compacting concrete (SCC). One of the current challenges in SCC technology is enhancing its durability and resistance to aggressive environments while maintaining self-consolidating properties. Addressing this challenge holds significant engineering importance, especially for infrastructure under freeze–thaw cycles and chemical exposure. The work aimed to determine the optimal polyfractional composition that ensures the maximum packing density of cement binder particles and to assess the changes in the operational characteristics of SCC. A software and calculation complex featuring a three-dimensional modeling algorithm, Drop and Roll, was used to select the optimal composition. Experimental studies were conducted for mixtures with varying fraction contents, differing in average particle sizes of 12 μm, 6.6 μm, and 4.9 μm. It was found that the optimum composition, consisting of 15% of the 1500 cm2/g fraction, 75% of the 3000 cm2/g fraction, and 10% of the 4500 cm2/g fraction, contributes to an increase in compressive strength of 26%, bending strength of 10%, a times two increase in freeze-thaw resistance, a decrease in water absorption, and an improvement in chemical resistance to aggressive environments. The results confirm the effectiveness of optimizing the grain composition of the binder to enhance the durability and performance characteristics of SCC used in aggressive conditions.