Preparation of sustainable ultra-high performance concrete (UHPC) with ultra-fine glass powder as multi-dimensional substitute material

Abstract

High cost and CO2 emissions are the issues that need to be addressed in the widespread application of UHPC. The application of mineral admixtures in UHPC has become a new development direction. Ultra-fine glass powders with median diameter d50 of 316 nm (named as nGP) and 5.33 μm (named as mGP) were fabricated to replace silica fume and blast furnace slag, respectively, to prepare eco-friendly UHPC. The outcomes of the study revealed that both nGP and mGP can significantly promote the hydration of UHPC pastes. The incorporation of ultra-fine GP increased the hydration products and improved the microstructure of UHPC due to its pore filling effect, nucleation effect and pozzolanic activity. The compressive strength of UHPC containing ultra-fine glass powders was larger than the reference ones and the optimal substitution rates of silica fume by nGP and blast furnace slag by mGP were 60% and 50%, respectively. Ultra-fine GP is feasible to be employed as multi-dimensional substitute material to produce low cost eco-friendly UHPC.