Concrete is the most widely used building material in the world, and it’s a major contributor to climate change. The carbon “embodied” in concrete accounts for about a quarter of the total greenhouse gas emissions from the global building sector. Fortunately, there are many new formulations, carbon capture technologies, 3D printing and other innovations that can reduce concrete’s impact without sacrificing structural performance or cost.

This guide provides a user-friendly overview of proven and scalable solutions to lowering the embodied carbon in concrete and cement products, while meeting the needs for design, specification, construction Campbelltown Concreting Solutions and operation. It is designed for students, researchers, academics and practitioners of all construction disciplines and is intended to serve as a reference to help advance the concrete industry’s climate-conscious innovation efforts.

The most common ways to lower the embodied carbon in concrete and cement include using blended cements with slag (and sometimes fly ash, red mud and natural pozzolans) and no OPC; incorporating waste materials into the mix such as recycled aggregates, blast furnace slag, blast furnace slag-derived granules, fly ash, red mud, trough slurry or synthetic aggregates made from sequestered CO2; introducing cellulose fibres to the concrete recipe; and deploying additives like retarders and air entraining agents to control the hydration reaction.

Another way to reduce embodied carbon in concrete is to use more recycled aggregates and avoid overuse of virgin aggregates, which require energy-intensive transportation. A study commissioned by the Portland Cement Association found that a typical cement and concrete plant can save more than half of its embodied carbon by using 100 percent recycled aggregate.

Self-healing bio-concrete, which is inspired by biology and modeled on the way that trees and human skin heal themselves, offers the potential to make concrete more sustainable. It has been tested to close cracks up to 0.03 inches wide, but research is underway to expand the size and width of the repair area to be more like regular concrete.

Dell said that other sustainable solutions to reduce the use of concrete include new construction methods, like 3D printing, and digitalization of the entire construction process. He added that construction sites often pour more concrete than needed to meet specifications, but the use of advanced computer models to optimize the packing of the concrete could go a long way toward minimizing this kind of waste.