US: A team from the Massachusetts Institute of Technology (MIT) has developed a new method to sequester CO2 in concrete before curing it. The method is based on the addition of bicarbonate of soda, which reacts with cement to produce a calcium carbonate-calcium silicone hydrate composite. The Journal of Engineering has reported that the method adds the benefits of CO2 mineralisation during production and casting, doubling the mechanical performance of early-stage concrete. It also eliminates the effects of carbonation reactions in cured concrete, which weaken the concrete by lowering its alkalinity, which accelerates the corrosion of rebar. The method has the potential to sequester 15% of CO2 emissions from cement production.

The team said “The pre-curing capacity of concrete to sequester CO2 has been largely underestimated and underutilised. Our new discovery could further be combined with other recent innovations in the development of lower carbon footprint concrete admixtures to provide much greener, and even carbon-negative, construction materials.”

Finland: VTT Technical Research Centre subsidiary Carbonaide has concluded its seed funding round, having raised funds worth Euro1.8m. Lakan Betoni, which produces precast and ready-mix concrete, led the funding, along with utilities provider Vantaa Energy. Carbonaide will use the funds to build an industrial pilot plant for its carbon neutral precast concrete product at an existing precast concrete plant in Hollola. The plant will bind captured CO2 in the product at atmospheric pressure. The process generates 50% lower CO2 emissions than precast concrete production using ordinary Portland cement (OPC). Suitable raw materials include ground granulated blast furnace slag (GGBFS), green liquor dregs and bio-ash. In trial production, the use of GGBFS gave Carbonaide's concrete a negative carbon footprint of -60kg/m3.

Other sources of loans and in-kind contributions included Finnish state innovation fund Business Finland.

Poland: Switzerland-based Holcim has acquired precast concrete producer HM Factory. HM Factory supplies precast concrete products manufactured in Poland to the Scandinavian export market. It employs 70 people across its operations.

Holcim’s Europe regional head Miljan Gutovic said “HM Factory is a perfect complement to our existing operations, offering multiple technological and raw material synergies. I look forward to welcoming the employees of HM Factory, whose expertise will be invaluable in accelerating green growth, especially in highly efficient modular construction.”

Canada: The city administration of Langford in British Columbia plans to enact regulations requiring all public and private projects to use reduced-CO2 concrete. It plans to support the rules with parallel measures affecting the design of buildings.

Victoria News has reported that the city authorities previously mandated reduced-CO2 cement for all projects in June 2022, but subsequently relaxed the regulations after only one company – Butler Concrete and Aggregates – completed the transition. Butler Concrete and Aggregates produces its reduced-CO2 concrete using slag cement supplied by Lafarge Canada.

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