Digital models for designing high-performance fine-grained concrete compositions using man-made raw materials

Introduction. This research focuses on the study of the composition and properties of fine-grained self-compacting concrete, including the development of a methodology for designing their structure. Methods and Materials. The following materials were used: Portland cement CEM I 42.5B; crushed stone screening of 2.5–5 mm fraction from the Kurlek quarry in the Tomsk region; sand from the Tuganskoye deposit was used as fine aggregate; quartz flour was used as microfiller; a complex modifying additive consisting of microcalcite from the Dalnegorsk mining quarry and nanosilicon dioxide obtained by the arc plasma evaporation method. Results and Discussion. The proposed methodology incorporates a computational and experimental approach that enables the selection of optimal combinations of aggregate fractions, fillers, and developed additives to achieve the required grain packing density. The use of statistical methods, such as polynomial approximation and Gaussian process regression, allowed us to identify the relationship between particle size distribution and concrete properties. Optimal ratios of each quartz aggregate fraction from man-made raw materials were determined for specific self-compacting concrete requirements in terms of concrete mix flow and hardened concrete strength. Conclusion. Laboratory tests confirmed the accuracy and effectiveness of the proposed calculations. Self-compacting concrete grade B40 compositions with reduced cement consumption (412 kg/m3) and high-performance` characteristics were developed.