Influence of intensive vacuum mixing and heat treatment on compressive strength and microstructure of reactive powder concrete incorporating secondary copper slag as supplementary cementitious material

A higher workability of the fresh RPC was obtained by mixing under atmospheric pressure. The presence of copper slag in the RPC had no adverse effect on compressive strength for all treatments. The heat treatment decreases the porosity and enhances the RPC strength. Assessment of the pozzolanic activity by means of the Frattini test indicates low pozzolanic reaction of the slag after 15 days. The presence of slag in the paste tends to decrease the total heat production of the paste. The use of copper slag as cement replacement in the RPC production decreases the energy consumption and reduces the carbon footprint.