Sensors that reveal when newly poured road concrete can be opened to traffic are just one way engineers at Purdue University are looking to improve durability and road work efficiency. Other methods include the use of self-healing and less carbon-intensive concrete.
WEST LAFAYETTE, Ind. — Self-curing concrete, self-healing roads, and concrete that reduces the global carbon footprint. Purdue University engineers are looking at new ways to pave roads, ways to extend the life of roads and ways to make roadwork less resource- and carbon-intensive.
Once new concrete is poured – whether in new road construction or in a patch on an old road – it takes a while for concrete to be ready to bear the heavy loads and stress of being driven on.
In 2019, a team led by Luna Lu, Purdue’s American Concrete Pavement Association Professor of Civil Engineering, developed sensors that can be embedded in concrete on the road to monitor strength through changes in hydration, stiffness, compressive strength and other qualities. The sensors run on electric energy that is generated when mechanical stress is applied to the patch – when something heavy runs over it.
The Indiana Department of Transportation has been using these sensors in spots along interstates 465 and 74 for nearly two years. The Purdue team is also working with the Federal Highway Administration to pilot the sensors in Texas, Colorado, Tennessee and Missouri, though Indiana was the first to implement them. The sensors allow engineers and INDOT to be confident in whether a concrete patch or road is ready for cars, trucks and other heavy vehicles to trundle across it. They can also track the concrete over its lifetime and predict when it needs to be replaced before it begins to fail.
“Our sensors could help make data-driven decisions to determine the construction schedule and improve the quality of concrete construction,” Lu said. “Being able to track concrete strength over a longer period of time would help engineers understand if they’ve over- or under-designed roads and better determine when to replace the concrete.”
The same sensors can also be used in the concrete of buildings, bridges, dams and other structures. This year, the American Society of Civil Engineers named the sensors “Infrastructure GameChangers.” A video of the sensors being installed is available on YouTube.