The world’s first on-site 3D printed large water tanks have been constructed in Kuwait by Abyan Building Construction Company using a Cobod 3D construction printer and achieving a 25 per cent savings on the amount of concrete and reinforcement that would be required in traditionally constructed tanks.

The two tanks were printed for Kuwait United Poultry Company and will be used for chicken drinking water at one of its many farms in the country.

The tanks measuring 4.5 m in height and with a diameter of 7 m were 3D printed with low-cost concrete in just five days and only contained macro fibres for the reinforcement of the tank walls and no traditional reinforcement meshes, according to a spokesman for Abyan.

“When constructing large tanks with the traditional method of formwork and concrete, the tank walls must be the same thickness from top to bottom because formwork cannot vary the thickness in height,” explains a spokesman for Denmark-headquartered Cobod. “3D construction printing does not have this limitation, allowing structural engineers to adjust the wall thickness where needed. Since gravity and water pressure make the bottom of the tank experience more stress, those areas need thicker walls. With 3D printing, the bottom walls can be made thicker and the upper walls thinner, saving materials and making the construction of the tanks both more economical and sustainable.”

The tanks in Kuwait had 40-cm wall thickness at the bottom part, 30 cm in the middle, and 20 cm at the top, leading to 25 per cent less concrete and reinforcement used for the walls, compared to if they had been cast with 40 cm walls all the way up, says the Abyan official.

The tanks were printed with a low-cost real C40/50 concrete mixed on-site using the D.fab solution and related printing equipment invented by Cemex and Cobod, where 99 per cent of all raw materials used are locally sourced, he adds.

To further increase the speed of execution, Abyan insisted on using macro fibers for the reinforcement of the concrete. Macro fibers have not been used for reinforcement of 3D printed real-life structural constructions before, so the requirements from Abyan presented a real challenge.

Henrik Lund-Nielsen, Founder and General Manager of Cobod, says: “Abyan pursues real innovations, which we really want to support and they wanted to try to avoid using any hard reinforcement in the walls, and just add fibres to the concrete. Of course, this challenged us a lot, but together with Cemex, the three of us were able to find a very good solution, which now can be replicated elsewhere in the future”.

Abyan’s willingness to be innovative and try out new solutions is a consequence of the scientific background of the CEO and co-founder of Abyan, Dr Ahmad Al-Nassem, a professor of structural engineering at Kuwait University. Dr Al-Nassem says: “Abyan is wholeheartedly committed to revolutionising the construction industry at large by integrating cutting-edge 3D printing technology within concrete construction along with innovative solutions in design and construction materials, bringing forth a new era of efficiency and sustainability. So, when all of our calculations showed that with 0.95 per cent macro fibres in the concrete, we could remove all hard reinforcement of the tank walls, we were keen to prove this new design concept with a real-life project.”

Due to the cost and time savings realised in the project, Kuwait United Poultry Company is keen to continue 3D constructing printing for tanks in the future.