With sustainability now a key factor when seeking to procure construction materials, a new study reveals that steel is more than twice as sustainable as plastic composites, according to a new independent study.

The study was carried out by environmental consultancy Beco on behalf of Rijksdienst voor Ondernemend Nederland, a Dutch government organisation, and included input from suppliers of all the main types of construction material – wood, concrete, plastics and steel.

In essence, steel is more than twice as sustainable as other materials when used to construct bridges.

The study, entitled Comparative Life Cycle Analysis of Bridges, analysed road and bicycle bridges.

It found that steel performs best in road bridges because of its low environmental footprint due to its relatively low weight as well as its excellent recycling properties. Compared to plastic composites, a steel road bridge has a 60% lower environmental footprint. Wood scores best for bicycle bridges, followed by steel, concrete and (at a distance) plastics.

Commenting on the study, Bauke Bonnema, general manager of Tata Steel’s Construction Centre in the Netherlands, said the findings were of great significance to designers and architects, construction companies and those responsible for materials purchasing for projects. “Increasingly, sustainability has become an important factor in selecting construction materials. This study confirms that steel is an extremely sustainable material: more than twice as sustainable as plastic composites,” Bonnema said.

According to Bonnema, steel can be endlessly recycled without loss of quality and is a true cradle-to-cradle material. meaning it is used but never consumed because it is recycled in a closed loop that can continue forever. “Recycled steel can be ‘upcycled’ into steel of a higher quality than the original material, a unique characteristic of steel. Wood and plastic composites are burned at the end of their lifecycles and concrete is ‘downcycled’ to roadfill material or gravel,” Bonnema added.

“From a resources point of view our society needs to develop into a circular economy, whereby materials can be fed back into the cycle in a closed loop process. That is why this study has taken into consideration the full lifecycle of the various materials, a necessary step in coming to a sound and balanced judgment about a material’s relative sustainability. As a cradle-to-cradle material, steel always remains part of the circle, making it perfectly sustainable and in line with the European Commission’s call this week for the establishment of a circular economy that conserves materials and resources,” said Bonnema.