Modified early-strength concrete mix

This paper suggests new early-strength concrete mixes composed of Portland cement, coarse and fine aggregates, a complex modifying admixture containing carbon nano tubes and bishofite produced at the Volgograd deposit. The paper represents the findings of scientific and experimental research and describes the impact of the suggested admixtures on the structure formation, rheological, physical and mechanical properties of the early-strength concrete. The micro-structural analysis revealed that the concrete mix containing a complex modifier is characterized by compact cement-and-sand matrix and a more homogeneous structure at the interface with the grains of the coarse aggregate. Review of the test results proved that the suggested composition and the complex admixture dosage contribute to decreased water-cement ratio, increased fluidity of concrete and a higher strength of hardened concrete at the early and final hardening stages.