Photo: T. Kaare Smith

Uses concrete like the ancient Romans

Construction and mechanics Construction materials Building construction Innovation and product development
Roman construction style inspired Professor Kristian Hertz (far left) to create ultra-light concrete structures. He has now patented the method.

One day towards the end of the 1990s, Professor Kristian Hertz from DTU Civil Engineering was walking around Hadrian’s Villa just outside Rome, when he asked himself a question: “What would I do if I were a skilled Roman engineer who suddenly found himself in the twentieth century, with all our contemporary building materials to work with?” The answer he came up with was: “Ultra-light structures”.

In the same way as the ancient Romans, Kristian Hertz combines several types of concrete in the same structure. But he does so by making a frame of strong concrete, which he then protects and stabilizes with light concrete. In this way, the strong concrete carries the load and can be placed precisely where it will provide the greatest benefit in the structure. This makes it possible to replace traditional concrete and steel structures with cheaper, lighter and more eco-friendly elements.

“When teaching the students, I make a point of telling them where the technology comes from. People find it easier understand what they are working with if they know how the construction technique arose, and when the people who learned to make concrete experienced their ‘light-bulb moment’,” explains Kristian Hertz.

In 2020, he founded the spin-out Abeo, which translates roughly from Latin as ‘out with the old’. Shortly afterwards, he successfully patented his ultra-light structures and—subsequently—the ‘string of pearls’ structures that are now used for building bridges. Today, the first ultra-light floor elements are being mass-produced and used in a variety of new building projects including Gl. Hellerup High School, the Innovest building and apartments on Krøyers Plads in the Christianshavn quarter of Copenhagen.

“The advantage of the ultra-light structures is that they grant architects much more flexibility, while providing much better soundproofing than standard floors. This means less noise disturbance between the storeys in a building. Moreover, tests have demonstrated that the new elements are able to withstand fire for four times as long as standard units,” concludes Kristian Hertz.

Article in DTUavisen no. 10, December 2014