Heavyweight Ultra-High-Performance Concrete with Micro-Reinforcement

The impacts of nano-silica addition, steel micro-reinforcement, and aggregate type on the mechanical properties and durability of ultra-high-performance concrete (UHPC) were studied. As aggregates, quartz and barite were used. The amounts of steel fibers and nano-silica were alternated. Six concrete mixes were produced with quartz sand, and the remaining six concrete mixes were designed with barite sand. Fibers made about 3-5% of the concrete composition’s mass. In a 2-5% concentration, nano-silica was used as a cement replacement. The inclusion of nano-silica significantly boosted the compressive strength of UHPC. The compressive and flexural strengths were also positively impacted by fiber supplementation ranging from 3% to 5%. The amount of fiber utilized proved to be more influential than the aggregate used. The UHPC concrete's durability was increased as all samples were highly resistant to freezing and thawing cycles. UHPC designed with barite aggregate demonstrated good X and gamma ray absorption at energies below 300 keV.