Roadmap to Carbon Neutrality

The first and most energy-intensive step in cement manufacture is the production of clinker from quarried materials like limestone, clay, shale, and sand. To reduce emissions associated with clinker production, cement manufacturers can incorporate industrial byproducts, like fly ash, that would otherwise end up in landfills, instead of virgin raw materials. These industrial byproducts have already been processed, so they no longer contain CO₂.

The industry is optimizing new blended cements that significantly reduce carbon intensity by using less clinker. These lower carbon cements use more limestone in cement composition, along with inorganic processing additions and other materials that reduce emissions. This new cement product is more sustainable and just as durable.

Mixing and delivering concrete requires energy. Concrete production facilities are shifting to renewable energy sources, with the ultimate goal of a 100% reduction in production energy by 2050, if not sooner. Concrete manufacturers have committed to the process of transitioning all delivery from diesel to zero-emissions fleets.

Many buildings are over-designed and use more concrete than is necessary. Architects can lower a building’s carbon footprint by optimizing design according to codes and standards. There’s a lot of waste, too, with 5 percent of concrete returned from construction sites each year. Optimized job sites will lead to zero waste and zero returned cement.

Concrete is porous, making it an effective carbon sink. It naturally absorbs CO₂ from the atmosphere and permanently sequesters it. This process can be accelerated with innovations in technology.