Recycled tyres form pavement that self-repairs when it rains
Rain would repair rather than damage roads if they were made of the tyre-based pavement invented by Israel Antonio Briseño Carmona, a Mexican student and winner of the nation's James Dyson Award.
The Coahuila Autonomous University student's rubber pavement is made of recycled tyres combined with additives that allow it to self-regenerate upon contact with water.
Carmona began his research wanting to solve the problem of rainwater damage to streets, which manifests as potholes and cracks.
"Damage is caused by rain filtering to the base of pavements, weakening it and creating subsidence," said the designer. "This is how the idea that turning the greatest degradation agent into a recovery agent was born."
There are other self-regenerating pavement materials in the world, but his appears to be the only one to harness water as a catalyst and to use waste tyres as its primary component.
Usually, concrete is combined with limestone-producing bacteria to make it self-repairing.
In Carmona's invention, that effect is created by a putty, which is formed by heating the tyre rubber and other additives into one homogenous mixture.
When it touches rainwater absorbed by the pavement, this putty creates calcium silicates, healing any cracks.
Carmona initially used standard asphalt instead of tyre rubber for the project, until he saw the opportunity to replace it with a common waste product.
He is planning to have the material certified for use in Mexico and ultimately hopes to offer it through his own construction company.
The pavement was the winning entry from Mexico in the national heats of the 2019 James Dyson Awards, which recognise the best in student design and engineering.
The overall international winner will be announced later this year. Other national winners this year include the UK's MarinaTex bioplastic, China's self-santising door handle and Switzerland's seaweed-fibre nappies.
Last year's grand prize winners were the UK team of Nicolas Orellana and Yaseen Noorani, who invented the O-Wind Turbine for cramped urban environments.