Floriade, the International Horticultural Exhibition, will feature several innovations for climate protection, including a high-tech new bridge built with an old material: flax. This plant-based material has been used for countless applications throughout history, including clothes, sacks and strong ropes for ships.
Showcasing its potential as a sustainable building material of the future, flax has been combined with a special bio-resin to create the “Smart Circular Bridge”, an EU project that will be showcased at Floriade Expo 2022.
In this bio-composite form, flax becomes a light, stable material that has similar properties to aluminium or steel. Flax is fast growing and has a smaller carbon footprint than many modern construction materials.
Eco-friendly solutions
The first “Smart Circular Bridge”, which can be found in Almere in the Netherlands as part of Floriade 2022, spans 15 metres. It was brought to life by an international consortium of 15 partners led by the Eindhoven University of Technology in the Netherlands. Two more bridges will be built, following this flagship construction.
In addition to the 100% natural flax fibres, the resin also comes from non-fossil sources as much as possible. The proportion of bio-resin is 25% for the first bridge, but it will reach 60% or more for the next bridges. This is achieved by using waste products from biodiesel production and recycled PET bottles.
AI helps make sense of the data
Research on these eco-friendly alternative materials is ongoing and the bridges will be systematically monitored in real-time. Nearly 100 sensors in the bridge provide data on how the material behaves while in use. A Structural Health monitoring system with optical glass fibre sensors in the bridge provides information on material strains, and acceleration sensors detect even the finest vibrations caused by wind.
This data is evaluated with the help of artificial intelligence (AI) and can be viewed on a dashboard on a public website. Engineers will be able to use this data to refine their calculations and material models, helping them to further develop materials and design models for the next bridges and many other applications, such as columns, façade elements and even rotor blades for wind turbines.
The circular economy
End-of-life options for these materials have been considered right from the start of the project. At the end of several decades, these bridges can be recycled in more sustainable ways: mechanical, chemical, and even biological recycling with fungi.
This project illustrates how innovations for climate protection and circular economy can successfully be put in place. Looking at alternative materials could have a huge impact in this area, as tens of thousands of bridges need to be replaced in Europe over the coming years.
“These materials have a great future,” says project leader Professor Rijk Blok from TU Eindhoven. “In particular, the intensive cooperation between science, industry, and communities has given a big push to materials development.”
Professor Dr Patrick Teuffel from TU Eindhoven, the lead partner in the international Smart Circular Bridge consortium, adds:
“The current results make us optimistic: we expect to build bridges with significantly larger spans and higher loads in the future.”
The King of the Netherlands will open Floriade Expo 2022 later this month. The features 400 participants from 33 countries, showcasing advances in horticulture and sustainability.
