Experimental investigations on performance efficiency characteristics of ultra-high-performance concrete (UHPC) with enhanced sustainable mineral admixtures
Sathyasai Regalla, N. Senthil Kumar
Abstract
Ultra-High-Performance Concrete (UHPC), defined by its low w/b ratio and dense microstructure, demonstrates superior durability compared to conventional concrete. This enhanced performance is primarily due to optimized particle gradation and reduced porosity, which collectively minimize permeability and enhance resistance to environmental and chemical degradation. As the demand for resilient and sustainable infrastructure continues to grow, UHPC is increasingly adopted in critical applications such as marine structures, high-rise buildings, and structural retrofitting. This study investigates the durability performance of UHPC incorporating locally sourced mineral admixtures, including silica fume, quartz powder, and glass powder, without the inclusion of steel fibers or specialized curing regimes. A detailed experimental investigation was conducted to assess key durability parameters: water absorption, void content, sorptivity, carbonation depth, rapid chloride ion permeability (RCPT), surface electrical resistivity, drying shrinkage, and x-ray micro-CT. Among all tested mixes, Mix 4 exhibited superior performance, with 1.33% water absorption, 2.84% void content, 1.66% micro-CT porosity with zero pore connectivity. The crystallinity index reached 79.82%, indicating a refined hydration matrix. RCPT was low 91 coulombs, and surface resistivity exceeded 345 kΩ·cm. Enhanced carbonation resistance and acceptable drying shrinkage confirmed Mix 4 as a technically viable, durable, and scalable UHPC solution using cost-effective, sustainable materials.