Asphalt made from biomass waste repairs road cracks on its own

A team of scientists from Swansea University in the UK and King's College London, in collaboration with Chilean scientists, have developed an asphalt that can close cracks without the need for human intervention for maintenance. The composition of the asphalt, which is partly derived from biomass waste, was determined with the help of artificial intelligence (AI).

Potholes in roads are a major traffic problem (not only) in the UK. The sticky bitumen used in asphalt mixtures hardens through oxidation and also cracks under the influence of temperature changes, so that road surfaces develop major damage and have to be repeatedly renewed. In the United Kingdom alone, this results in costs of 143.5 million pounds sterling per year, around 172.5 million euros.

The British researchers have set themselves the goal of reversing cracks as far as possible to reduce road repairs to a tolerable level and make roads more durable overall.

Simulating bitumen compositions

The researchers used a machine learning method to investigate organic molecules in complex liquids such as bitumen. The scientists' aim was to minimize bitumen oxidation and thus the formation of cracks. To do this, they used a data-driven model to perform atomistic simulations more quickly, as they describe in their study “Data-driven representative models to accelerate scaled-up atomistic simulations of bitumen and bio-based complex fluids”, which was published in Digital Discovery. Google Cloud and the AI tools Gemini and Vertex AI were used. The researchers simulated the behavior of different compositions of bitumen.

In the end, plant spores were used as a tiny, porous material that was filled with recycled oils. These oils are released as soon as the asphalt begins to crack. The cracks then seal themselves – again in a short space of time. In the laboratory, the researchers were able to prove that microcracks in the asphalt surface were able to completely close again within an hour.

The research is still at an early stage, the British scientists admit. However, they believe that asphalt made from biomass waste and other sustainable materials can reduce dependence on oil and natural resources. Biomass waste is available locally everywhere and, above all, is inexpensive.

The scientists now want to press ahead with the development of self-healing asphalt. They are currently experimenting with biopolymers made from brown algae and plant oils. They are also investigating the use of thermally converted old tires for use in self-healing asphalt.

(olb)