UK: CemFree cement-free concrete has been applied volumetrically for the first time in a 52m3 repair to the Woodford West Viaduct on the M25 London ordbital motorway in Essex. The reason behind the choice of method was the unavailability of batching plants at night, which was the only time that a team of Jackson, DB Group and Axtell employees working on behalf of Connect Plus were permitted to perform the work on the UK’s busiest road. CemFree said that 9.4t of CO2 emissions were cut by comparison to the same project undertaken with ordinary Portland cement (OPC). Jackson director of highways Paul Watson said, “We hope this marks a turning point on the M25 and the wider Highways sector for using low carbon alternatives.”
Cemfree uses 95% ground granulated blast furnace slag (GGBFS) and a 5% alkali activator, removing the need for cement. This gave CO2 emissions of 114kg/t, which the company says is 77% lower than conventional (OPC).