Influence of silica fume and ground granulated blast furnace slag on the engineering properties of ultra-high-performance concrete

The supplementary cementitious materials (SCMs) are used as an alternative material to reduce environmental concerns. Using industrial waste as an SCM can also help to reduce the amount of garbage deposited in lagoons and landfills and can have strength, durability, economic and environmental benefits. Ultra-high performance concrete (UHPC) is a new type of concrete with improved mechanical and durability properties. There is just a little amount of information on the impact of different SCMs on UHPC mechanical and durability performance. This paper presents the mechanical and durability properties of UHPC containing Silica Fume (SF) and Ground Granulated Blast Furnace Slag (GGBS). Mechanical properties of UHPC such as compressive, splitting tensile and flexural strengths were studied. Moreover, its resistance to chloride ions penetration was evaluated along with Sorptivity. According to the test findings, the strength properties of GGBS-based UHPC are significant up to 40% cement replacement level under normal water curing. Furthermore, the inclusion of 12% SF and 40% GGBS demonstrated superior mechanical and durability characteristics as compared to their binary counterpart. In terms of the synergistic effects of GGBS and SF, the efficiency factor (k value) was computed as an indicator to predict the compressive strength of UHPC. Oven curing at elevated temperature for 48 h and thereafter normal curing improved the results of early age compressive strength significantly.