Team cuts sand use in concrete

Researchers from Brunel University London have developed a new method for making concrete a more sustainable material.

The authors of an article about future cities – Dr. Seyed Ghaffar, Dr. Mehdi Chougan and Dr. Pawel Sikora of Brunel University – recognise that concrete will remain a widely used construction material in future cities, but they want the material to be more sustainable. Concrete flooring is widely used in commercial buildings as it is durable, easy to maintain and cost effective. Traditionally, it has a high sand content, and the demand for sand currently outpaces the speed at which is it being replenished by the weathering of rocks. The team therefore wanted to find a way to make concrete without taking more sand from its environments.

The researchers obtained brown beverage glasses from a glass recycling company, which was crushed finely, washed, milled and dried. The glass particles were then used instead of sand to make concrete for a 3D concrete printing machine, which made blocks suitable for building construction. They also replaced some of the Portland cement in the concrete with limestone powder, which has a lower environmental impact. Lightweight fibres were added to improve the insulation properties of the concrete.

The new concrete is not produced with zero carbon emissions, but the researchers see it as a step towards a net zero goal. The article by the Brunel University researchers does not estimate the cost of their new concrete compared to that of traditional concrete.