736m3 of cement-free concrete poured in London Power Tunnels project

UK: Contractors poured 736m³ of cement-free concrete in an 11-hour continuous pour at the Hurst substation tunnel drive shaft of the London Power Tunnels project on 11 May 2023. Construction Index News has reported that Capital Concrete supplied the concrete. It uses a formula developed by Earth Friendly Concrete to replace 100% of cement with fly ash and ground granulated blast furnace slag (GGBFS) in the presence of an activator and admix solution. The supplier said that the concrete will reduce CO₂ emissions by 64% compared with ordinary Portland cement (OPC), corresponding to 111kg/m³ of concrete.