Engineers from Brunel University in London have embarked on a three-year project to develop 3D-printed interlocking building blocks using recycled building waste materials.
The Lego-style blocks hope to decrease carbon emissions caused in the construction process by reducing the amount of virgin concrete and cementitious materials sourced for building materials.
Seyed Ghaffar is the project lead and associate professor in civil engineering at Brunel University and said nothing like this project had been tried before.
“Demonstration projects built over the past few years have shown both the viability and potentials of 3D printing technologies,” Ghaffar told Brunel University London. “However, these projects have used conventional raw materials in their concrete feedstock.
“The use of recycled, waste-driven secondary raw materials to replace virgin aggregates for 3D printing of a building block has not yet been done, but we hope to demonstrate it with this project.”
Some measures suggest about 0.85 tonnes of carbon dioxide are released for every tonne of cement, so the project aims to minimise this number through recycling.
“Our objective is to decrease the CO2 footprint of printed products against traditional virgin concrete and cementitious mortars, through the development of printable mixtures that will use up to 100 per cent recycled aggregates,” Ghaffar said.
Concrete is the second most used substance on Earth, after water, and 29 million cubic metres of it are used in Australia every year. That’s enough to build a footpath around mainland Australia more than 10 times.
Ghaffar underlined that concrete supports the bulk of the extractive industries, and its carbon emissions warrant serious consideration.
“Nearly half of all materials extracted from Earth annually are used in concrete, and extraction of construction virgin aggregates is the main part of the global non-metallic mineral consumption,” Ghaffar said.
The project aims to produce recycled bricks measuring 50cm2 to form an interlocking wall.