HOW CEMENT MANUFACTURERS CAN IMMEDIATELY USE SLAG TO REDUCE CARBON FOOTPRINT

A new report from The Rocky Mountain Institute states that there are ways in which the construction sector can act immediately and reduce industry carbon levels, despite the industry goal of eliminating all carbon in concrete by 2050.

Authors of the report, Radhika Lalit and Ben Skinner, say that Supplementary Cementitious Materials (SCM's) like slag and fly ash can be of use to the industry's goals of reducing carbon levels - because of the little to no emissions associated with slag and fly ash use.

Lalit states that by using these SCM products, manufacturers can immediately begin contributing to lower carbon levels in the industry by reducing the amount of concrete needed.

"Around the laying of the concrete, you can use less concrete in the first place. SCM's such as fly ash, slag, volcanic ash and calcined clays have little or no associated emissions and can be introduced into the cement blend to replace a portion of clinker", Lalit said.

"What gives us hope is the fact that there is a big rise in ambitions across the industry (to reduce emissions), where companies, corporations, real estate players, anybody who's constructing new buildings, new ports, new highways, new roads, is looking into these materials".

Skinner stated that "Historically the construction industry hasn't been incentivised to consider embodied carbon when creating our built environment. The focus has been on reducing costs, not carbon. Companies are hesitant to take on anything perceived as additional risk. With that being said, we are starting to see some great developments all across the value chain, and it's an exciting time in the construction space".

The report emphasises the need for a more comprehensive systems approach towards lowering carbon emissions, and that it has to be a combination of everything - from more efficiency in cement and concrete production through using SCM's, to utilising more efficient designs in construction.

Should the concrete industry effectively meet their goal of eliminating all carbon in concrete by 2050, SCM's such as slag and fly ash will be critical players in achieving the industry's goal.