3D Concrete Printing: A Major Ecological Asset for the Construction Industry?

With its dependence on fossil fuels, high carbon footprint, labor shortages, and technical constraints, the construction industry is facing significant environmental challenges. 3D concrete printing is a groundbreaking technological innovation that promises to reshape the future of the construction sector. Offering numerous technical, economic, and most importantly, ecological advantages, it aligns with an eco-responsible approach. One of the key challenges for the construction industry, low-carbon building, will help reduce the sector's carbon footprint and move closer to the goal of carbon-neutral buildings.

To understand the challenges of tomorrow, it is essential to reflect on the current state of the market. Since traditional construction methods contribute one of the largest carbon footprints across all industries, it is crucial for professionals to adapt and innovate. The construction sector is one of the leading contributors to global greenhouse gas emissions. According to a study by ADEME (French Agency for Ecological Transition), it accounts for 25% of the average French citizen's carbon footprint, whereas individual waste accounts for only 3.6%. The sector's dependence on fossil fuels is substantial. Gas and fuel oil make up 40% of the total energy consumption in the industry. Large amounts of embodied energy are used in the production of materials, significantly increasing the environmental impact of traditional building construction. Concrete, for example, is one of the most energy-demanding materials. Therefore, quick action is necessary, and the construction industry is starting to recognize this need. The building sector is moving towards more sustainable practices to reduce its carbon footprint and aim for carbon neutrality. Faced with global awareness and the climate emergency, many innovations have emerged to improve the ecological impact of construction. Supported by the government through stricter regulations such as the RE2020 standard, the sector also benefits from the support of external organizations to assist market players. ADEME, the Agency for Ecological Transition, offers support for responsible projects. In 2019, ADEME partnered with Constructions-3D, marking the start of a strong collaboration. Iman Bahmani Piaseczny, Coordinator of the Transversal Research – Innovation – Future Investment division at ADEME, recalls this collaboration and emphasizes that "The various innovations fully meet our expectations. They will gradually transform construction techniques and business models in the building industry to enhance resilience in the face of climate challenges."

3D printing has quickly become a valuable opportunity for numerous sectors, attracting an increasing number of users who find it an immediate solution to their needs. Naturally, the construction industry has also embraced this technique and partnered with industry experts to address its challenges. As a pioneer in 3D concrete printing, Constructions 3D embarked on the development of 3D concrete printing machines to build the structures of the future. Using similar printing techniques but on a larger scale, 3D concrete printing has quickly become an effective solution to reduce the CO2 emissions of the construction industry. To meet the demands of the sector, materials had to be adapted to fit the specifications. For over a decade, industry players have been researching and developing effective solutions to enable eco-friendly 3D-printed buildings. Operating like a traditional 3D printer, the machines were reengineered to print large volumes of concrete on construction sites. Concrete, the primary material used in this type of construction, was redesigned to reduce drying time and to be compatible with the machine. The challenge was to develop a concrete mix that would flow smoothly without clogging the printer while maintaining its original shape. Additionally, the concrete must meet regulations to withstand weather conditions and the overall weight of the building. In order to meet market expectations and with a continued focus on eco-responsibility, every stage of building construction is rethought to reduce the carbon footprint. Insulation, for example, is a key issue. In 2019, Constructions-3D began using an insulating material made from locally sourced flax shives in its building projects. To envision zero-carbon construction in the future, it is therefore necessary to rethink the design of buildings as a whole.

The technical advantages of this type of printing are significant. Typically used in construction, concrete formwork is eliminated, contributing to waste reduction and lower production costs. Thanks to the mobility of the machines and the more malleable concrete, low-carbon building constructors have unlimited freedom of design, unlike traditional construction methods, which are limited in execution. This leads to an era of ultra-customization in construction. In the past, certain design requests were impossible to fulfill. The 3D machine provides quick execution, allowing professionals to save considerable time. Construction time is reduced by 50% to 70%. More competitive due to faster construction times, 3D concrete printing offers attractive economic benefits. With controlled printing and material reduction, expenses can be lowered, especially through optimized concrete usage. The volume of concrete used is reduced by 20% to 30% compared to traditional construction. Staying within the framework of green, sustainable, and responsible building, labor practices are rethought. Work-related strain is significantly reduced thanks to the automation of the construction process. This leads to better working conditions, fewer on-site accidents, and a decrease in occupational diseases caused by repetitive physical tasks. Workers’ exposure to weather conditions is also reduced. Site noise is diminished by 40% to 60%, enhancing the comfort of construction workers. When it comes to reducing the carbon footprint of 3D concrete printing, the benefits are numerous. Waste reduction is a major advantage of this innovation. This green technology uses less material during building construction. Its printing process allows up to 70% less waste to be produced. The mortar contains less cement, making the material more eco-friendly and reducing its environmental impact. To further cut CO2 emissions through 3D concrete printing, insulating materials are carefully selected, and these materials are carbon-negative. This technology is more environmentally friendly and less energy-intensive than traditional construction. There's no longer a need to transport materials to the construction site as the structure is directly printed on-site. This leads to significant energy savings, with transportation reduced by nearly 50%. Researchers Habert and Ouellet-Plamondon estimate that the overall carbon footprint of the construction industry could be reduced by 20% to 40%. Thus, 3D concrete printing presents a considerable opportunity for the construction industry to significantly lower its carbon footprint and global ecological, economic, and human impact.

3D concrete printing in construction is a challenge that has attracted many industry players. It’s a race for development and innovation. At Constructions 3D, we have developed Termix 3D, an innovative technology dedicated to the local production of printable micro-concrete. The future goal is to facilitate 3D concrete printing through micro-factories located on construction sites. The future looks bright with sustainable construction and zero-carbon buildings. For the construction industry, reducing CO2 emissions is a top priority, and it can rely on new green technologies to lower its ecological impact.