Why Admixtures Are the Future of Sustainable Concrete

Despite its widespread use, concrete is not known for its sustainability. In fact, its manufacturing process alone is responsible for about 5 to 7% of global carbon dioxide (CO2) emissions. For these reasons, there is a strong push in the construction sector to make concrete more sustainable.

One emerging area of interest involves the use of admixtures. These chemicals are added to the concrete in small amounts to modify its properties — both while the concrete is still fluid and also after it has hardened. Many of these admixtures are made from polymers, including the polycarboxylates we make here at NAII.

How Admixtures Enhance Concrete

Admixtures promote the sustainability of concrete in several ways. For example, they enhance concrete’s durability and strength while at the same time decreasing its water-to-cement ratio. By enabling the use of less water, admixtures reduce the porosity of the concrete, thus extending the life of the material.

Admixtures also catalyze cement hydration, or the process by which Portland cement hardens after the addition of water. In particular, these chemicals can help concrete systems made from supplementary cementitious materials (SCM) maintain the desired performance characteristics with less clinker. Clinker plays an important role as an intermediary product in the manufacture of Portland cement. Producing it, however, involves heating up limestone in a kiln — a process that requires a substantial amount of heat and also releases CO2. Fortunately, even a very small amount of admixture can reduce the amount of required clinker by up to 20%. With the correct proportioning, this amount can more than double.

Building a More Sustainable Future

Thanks to these modifications to traditional concrete, admixtures can significantly reduce the embodied carbon of concrete, all while maintaining and even enhancing the properties of the material. We believe admixtures, including our own polycarboxylates, will play an increasingly important role in improving concrete’s environmental footprint, enabling you to meet your sustainability goals.

To learn more about our sustainability initiatives, check out our website.