Bio-Based Composite Bridge – Lessons Learned

The concept and design process of the world's first bio-based composite pedestrian bridge at the campus of Eindhoven University of Technology was described and presented at the previous IASS conference in Tokyo [1], [2]. The bridge has a span of 14 m and uses a bio-composite as the main structural material, which is based on hemp, flax and Greenpoxy. In the meantime the project has been successfully realized and finished in November 2016.

The focus of this paper will be on a couple of major aspects, that can be helpful for future projects using bio-based composite materials: evaluation of the material tests, comparison of the FEM analysis with the 1:1 scale load test, production process as well as the monitoring of the bridge after installation. In order to understand the material properties in a better way a series of tests have been and still are being conducted in the laboratory at TU/e. Apart from the prior essential tests, such as strength and stiffness, further ongoing tests look at the creep behaviour of the composite material. The installation of the bridge was carried out in public space, so full approval of the authorities had to be obtained. Due to the fact that no building codes exist for bio-based composite materials the authors had to prove the correctness of their calculations with a full scale load test. At the moment the longterm behaviour of the bridge is monitored with in total 27 fibre-optical sensors to further study and evaluate the strain properties over a period of 1 year with varying environmental conditions. It can be concluded that bio-based composite materials show a great potential for applications in the built environment, while also a long list of questions remains for researcher to be answered.