UK-based Keltbray has partnered with Australian cement maker Wagners and London-based supplier Capital Concrete to use a minimum of approximately 11,000 cubic meters of Wagners’ zero-cement, geopolymer concrete by the end of June. Keltbray previously used the material, dubbed Earth Friendly Concrete, for the Charterhouse Place project in central London.
Keltbray has committed to using at least 11,000 cubic metres of a low-carbon concrete in its projects by the end of June next year.
The guarantee is part of a deal struck with Australian cement maker Wagners and London-based supplier Capital Concrete, which will see the contractor deploy Wagners’ Earth Friendly Concrete (EFC) in both permanent and temporary works.
EFC is described as a zero-cement, geopolymer concrete with a claimed 50 per cent saving in embodied carbon over conventional piling concrete. Its binding agent is made from two industrial waste by-products: blast furnace slag from iron production and fly ash waste from coal-fired power generation.
Keltbray said the agreement “comes on the back of increased stakeholder interest and demand for significant reduction in embodied carbon”.Low-carbon concretes like EFC typically come with a price premium of at least 10 per cent but can also offer material advantages in addition to their eco-credentials.READ MORE
The finely divided residue that results from the combustion of ground or powdered coal and that is transported by flue gases from the combustion zone to the particle removal system.
Fly ash is a by-product from the combustion of pulverized coal, and is widely used as an ingredient in hydraulic-cement concrete. Because it improves many desirable properties of concrete, it is introduced either as a separately batched material or as a component of blended cement. Fly ash reacts with the hydrating hydraulic cement to form a cementing medium.
Slag in Concrete
Granulated blast-furnace slag that has been finely ground and that is hydraulic cement.The use of slag in concrete has several benefits, including reduced energy, reduced greenhouse gas emissions, and reduced use of raw materials.
arious types of slag are produced: – Blast-furnace slag—The nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and of other bases, that is developed in a molten condition simultaneously with iron in a blast furnace. – Air-cooled blast-furnace slag—The material resulting from solidification of molten blast-furnace slag under atmospheric conditions; subsequent cooling may be accelerated by application of water to the solidified surface.
– Expanded blast-furnace slag—The lightweight, cellular material obtained by controlled processing of molten blast-furnace slag with water or water and other agents such as steam, compressed air, or both. – Granulated blast-furnace slag (GBFS)—The glassy granular material formed when molten blast-furnace slag is rapidly chilled, as by immersion in water.
Ground-granulated blast-furnace slag (GGBFS)—Now known as cement, slag—granulated blast-furnace slag that has been finely ground and that is a hydraulic cement.