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. 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 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% of all raw materials used are locally sourced. To further increase the speed of execution, Abyan used 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. “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 fibers 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,” said Henrik Lund-Nielsen, Founder and General Manager of COBOD.
“It is in the DNA of Abyan to be innovative. Abyan is wholeheartedly committed to revolutionizing 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% macro fibers 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,” said Dr. Ahmad Al-Nassem, CEO and Co-founder of Abyan, who is a professor of structural engineering at Kuwait University.
The two tanks were printed for Kuwait United Poultry Company and will be used for chicken drinking water at one of their many chicken farms in Kuwait. “We are very happy about the results of this project and for the huge savings in time. We will surely repeat this method in the future and get more 3D printed tanks for our many chicken farms,” said Muhammad Al-Hussain.
