The study investigates patterns in the formation of the structure and properties of calcareous-ash mortars modified with silica rock opoka and recycled basalt fiber. The research goal was to establish the relationship between the composition, pore structure, and thermophysical and physico-mechanical characteristics of the material.
The raw components used included lime, fly ash, granulated blast furnace slag, opoka, quartz sand, and recycled basalt fiber obtained from spent mineral wool substrate after heat treatment. The conducted studies involved the determination of density, compressive and bending strength, thermal conductivity, shrinkage strain, and microstructure.
The introduction of opoka was found to contribute to the formation of a microporous structure, providing a 20-35% reduction in average density and a decrease in thermal conductivity to 40-55%. Recycled basalt fiber reduced shrinkage strain and improved crack resistance by stabilizing the pore matrix structure. The study showed that synergetic interaction of components leads to the formation of a hierarchical structure providing the optimal combination of strength and thermophysical characteristics.
The optimal density range achieving the best balance of properties has been determined (1,400–1,600 kg/m³).