Вплив технологічних факторів на властивості реакційних порошкових бетонів на основі шлакопортландцементу, активованого лугами

The development of reactive powder concrete (RPC) based on Portland cements containing varying amounts of granulated blast furnace slag and activated with soluble sodium silicates is of global importance in terms of protecting critical infrastructure. The article identifies factors influencing the kinetics of strength gain, inherent shrinkage deformation and impact strength of reactive powder concretes when using sodium metasilicate pentahydrate as an alkaline activator in various aggregate states (powder, solution), as well as soluble sodium silicates with a silicate modulus of Ms = 2...3. It has been shown that changing the ratio between slag portland cement and sand from 1:3 to 1:1 and using sodium metasilicate in powder form ensures the production of sand concrete with compressive strengths of 35.7, 63.8, 87.5, 118. 1 and 123.9 MPa after 1, 3, 28, 180 and 360 days, respectively. The use of sodium metasilicate in the form of an aqueous solution significantly accelerates the kinetics of strength gain and provides a strength of 52.3, 85.0, 108.7, 126.1 and 141.1 MPa after 1, 3, 28, 180 and 360 days, respectively. The introduction of finely dispersed calcite reduced the shrinkage during drying of RPC by 1.2...1.6 times. Reducing the OPC content from 45 to 5% by mass with a water silicate glass modulus of 2.6...2.7 resulted in a slight decrease in the early compressive strength of ultra-rapid hardening RPC, but provided a significant increase in the compressive strength limit from 112.5 MPa to 132.4 MPa after 28 days. Viscous fracture after 28 days is confirmed by a better brittleness coefficient of 5.3...5.9 and 10.5...28.7% higher impact toughness of samples on sodium metasilicate and sodium disilicate compared to the analogue based on OPC. RPC with stable long-term strength, high impact toughness, and reduced shrinkage during drying has been obtained. The introduction of bleaching agents in the form of CaCO3 and mineral pigments allows decorative RPC to be obtained. The possibility of obtaining products by extrusion based on alkali-activated RPC, with the determination of the main technological parameters of the process, is indicated.