Properties and applications of ultra-fine composite mineral admixtures prepared by fly ash

In recent years, with the rapid development of China's infrastructure and green high-performance concrete, as well as to achieve carbon peaking and carbon neutrality goals, the demand for green high-performance mineral admixtures is increasing. Ultra-fine composite mineral admixtures were meticulously crafted through the synergistic ultra-fine grinding of secondary fly ash and S95 mineral powder, incorporating varying ratios and a strategic quantity of grinding activator. This study delved into the fineness, specific surface area, fluidity ratio, setting time, activity index of these admixtures, the comparison with the main commercially available ultrafine powder, along with their application potential in cement and concrete. The findings underscore the remarkable performance of the admixtures, with a specific surface area reaching 780 m²/kg, an activity index soaring to 118%, and a fluidity ratio exceeding 112%, all exceeding the technical benchmarks set for S95 and even approaching S105 mineral powder standards. When 20% of P