Expert: Holiday traffic jams could be prevented by ‘smart concrete’

Luna Lu’s research is enabling concrete-paved roads to prevent and repair their own damage. (Purdue University photo/John Underwood)

THANKSGIVING TRAVEL: As an expected 13% more Americans prepare to travel for Thanksgiving this year, construction on major interstates could leave millions in traffic jams. Purdue University civil engineering professor Luna Lu can discuss how her research is working to cut down on road repairs and traffic through the development of “smart concrete.”

“Traffic jams caused by infrastructure repairs have wasted four billion hours and three billion gallons of gas on a yearly basis. This is primarily due to insufficient knowledge and understanding of our infrastructure’s condition,” Lu says. “For instance, we don’t know when concrete will reach the right strength needed for opening up major roads to traffic after construction. In many states, major interstates need to reopen in a 12-hour window, which only leaves three to four hours for concrete to cure. The concrete may go through premature failure, leading to frequent repairing.”

SMART CONCRETE: Lu and her students have invented technology that addresses two big challenges in road construction: figuring out exactly when concrete is strong enough to handle heavy traffic and improving the durability of concrete. In reducing the frequency of road repairs, these inventions could also save millions of taxpayer dollars.

Road sensors: To better communicate with concrete, Lu’s lab has developed sensors that wirelessly track concrete strength development in real time, giving engineers more precise data on how much time is needed before traffic can use new concrete pavement. In 2019, the Indiana Department of Transportation began embedding these sensors in Indiana highways. Lu has also been working with the Federal Highway Administration to embed the sensors in other states, including California, Texas, Missouri, Tennessee, Colorado and North Dakota.

Self-healing concrete: Harsh winters can cause concrete to crack. Lu’s lab discovered that mixing nano-silica materials into concrete can help the mixture to seal its own cracks while regaining strength. The healing process also prevents water from seeping into the concrete and corroding steel or rebar reinforcement.

NEXT UP – SMART ASPHALT AND SOIL: Lu’s research currently applies to concrete, the most challenging road material to repair, but could resolve issues with other road materials in the future.

“Like with concrete, we can understand the conditions of strength for materials such as asphalt and soil, and use that information to determine traffic opening time,” Lu says.