Influence of nanoadditives on the physical and mechanical performance of cement concrete

Introduction. The influence of nanoadditives on the physical and me-chanical performance of cement concrete remains a relevant issue driven by the need for finding the most promising and cost-effective solutions to enhance performance during in situ concreting. This issue has been thoroughly examined by the authors in earlier publications. Methods and Materials. Two experimental formulations of a composite concrete nanoadditives were developed, based on ammonium hexafluorosilicate ((NH4)2SiF6) and silicon carbide (SiC). Results. In the first part of the study, concrete samples were tested after 28 days of hardening to assess mechanical strength properties. The kinetics of hardening and the influence of each of the specified additives on the concrete were studied. Discussion. The conducted studies allowed for the establishment of the optimal combination of nanoparticles included in the special additive, as well as a detailed investigation of the mechanism of strength gain in cement stone. It was found that the use of the best additive formulation (combination No. 2) significantly improved the strength characteristics of the concrete mix, providing an average strength increase of 38%, as confirmed through both destructive and non-destructive testing. Conclusion. The optimal dosage of nanocomponents for the production of the recommended additive per cubic meter of concrete is approximately 0.0141 of the mass of the main raw material, which confirms the economic feasibility of its application. In addition, low concentration of nanoparticles in the additive ensures environmental compatibility of the finished product, minimizing the impact on the environment. The optimal dosage of nanocomponents ensures the uniform distribution of particles in the concrete structure, contributing to an increase in its durability and resistance to environmental influences.