Industrial waste-based submicron additives in cement mortars

Abstract

Purpose: The aim of this work is the development of materials and technologies, which provide their repeated life cycle. Methodology/approach: Scanning electron microscopy, thermogravimetric analysis, X-ray diffraction analysis. Research findings: The processing method is proposed for fluorocarbon-containing waste (RUSAL, Krasnoyarsk) resulting in the formation of submicron-sized carbon in the form of a coal-water slurry for solution and/or concrete modification. It is shown that carbon in the coal-water slurry represents flat plates with the submicron-sized particles. The degree of cement hydration increases with the addition of wastes, indicating the material strengthening, which is consistent with the results of strength tests. The acicular spike crystals of hydrated calcium silicates become larger and thicker, that confirms the assumption that hydration increases with the addition of submicron-sized carbon particles. Practical implications: The obtained physical and mechanical properties of the cement-sand mortar show the possibility of using the proposed modifiers in the production of materials with high bending strength at early stages to reduce cracking, especially in thin concrete layers with a large coverage area.