Ultra-High-Performance Concrete (UHPC): A microstructural and particle packing investigation

Abstract

This study examines into optimizing the composition of dispersed cement systems to reduce inter-particle voids, thereby enhancing solidity and density. The investigated concrete mixtures contain micro silica, granular blast furnace slag that has been finely dispersed, superplasticizer Glenium 430, high-valence hardening accelerator, and two fine aggregate fractions: 10–15 mm granite crushed stone and Portland cement grade 53. Laser analysis was used to analyze the size and shape of the particles, and the structure of the cement block was investigated using X-ray phase analysis, thermographic analysis, and scanning microscopy. The optimized concrete’s compressive strength was evaluated at five and twenty-eight days; the results showed values of 52–74 MPa and 128–163 MPa, respectively, at cement utilization levels of 650–750 kg/m3. It was shown that the use of a bimodal clinker component and granulated blast-furnace slag blend was effective. Furthermore, there is empir-ical data suggesting confirms the optimal amounts of nanoscale additions, such as micro silica, required to get the most favorable outcomes.