Promising Developments in 3D Printing for Construction

In the face of an ongoing housing shortage, 3D printing – including automation and robotic machinery – has been hailed as a way to construct buildings and infrastructure quicker and less expensively. Multiple efforts are underway to identify 3D printing materials that can make the needed improvement in productivity, while living up to evolving sustainability goals in the industry.

One of those 3D processes, concrete printing, has increased in popularity significantly over the past five or so years. This innovative process, with the potential to get construction over the hump of shorter schedules and the skilled labor shortage, was explored recently in a report on ScienceDirect.com.

In addition to enabling the creation of complex, customized structures, 3D concrete printing also brings the advantages of reduced waste materials, greater accuracy, more uniform results, and faster construction times. Research is ongoing into using waste materials as supplements to the cement portion of a concrete mix, keeping in mind its effect on the way concrete flows and deforms, as well as its strength. The article summarizes that concrete printing mixes will heavily influence the use of 3D concrete printing for better economic and environmental outcomes.

A Colorado-based company recently completed a remarkable 3D-printed expansion of a Walmart in Tennessee. At twenty feet tall with a footprint of about 8,000-square-feet, the addition became one of the largest free-standing 3D printed commercial concrete structures in the US.

Companies in England are working together to develop low carbon types of graphene-infused mortar that can be 3D printed for use in roads, bridges, water/wastewater systems, and other civil construction. This 3D printing mortar will incorporate a graphene additive, which results in a lower carbon version of mortar. The Graphene Construction Materials Market report by Graphene-info explains that graphene can provide vital benefits to the construction industry like enhancing the performance of materials, lowering costs and reducing carbon emissions. Graphene-enhanced construction materials are already in use and, pending changes to design codes and regulations, that usage is anticipated to increase.

Representation of graphene nanomaterial

At the University of Virginia, researchers are developing another type of graphene enhanced concrete for 3D printing. The composite material combines graphene with limestone and LC2 (calcined clay cement) for better mechanical performance and a lower environmental impact.

Another advancement in 3D printing involves glass, a recyclable building material. A team at Massachusetts Institute of Technology (MIT) has created interlocking 3D-printed glass bricks that reportedly rival the crush-resistant properties of concrete blocks. A report from MIT News describes the glass bricks as similar to LEGO blocks in that they can “be disassembled at the end of a building’s lifetime and reassembled into a new structure.” The report also explains that, if it is not contaminated, glass itself can be recycled “almost infinitely.”

On the topic of recycling, ScienceDaily has reported on research in Australia that indicates up to 70% of textile waste – carpeting and fabrics – could be suitable for conversion to fiber and added to concrete. This would increase its strength and reduce shrinkage cracks by up to 40%. There are already 3D printing companies that offer carbon fiber reinforcement options, and the use of textile fibers will enable more successful curvatures and freeform concrete projects.

Tests continue to be conducted on the variety of 3D printing options to determine how durable and cost effective they are compared to traditional construction methods. There are hopes that all of these technologies will help address current and future housing issues, while simultaneously promoting sustainability.

Download the GRAITEC e-book “An Introduction to Sustainability in the Built Environment,” and learn how sustainable design and building performance can go hand-in-hand.