A pilot awaiting runway repair to fly a military mission or a restless driver stalled in traffic due to road repair wants nothing more than to get moving. A new material created by TTU engineers allows rapid, easy and relatively inexpensive repairs of airfields and highways when time is of the essence.

The new material, dubbed ZOOM, debuted after the Tennessee Department of Transportation requested a product that could help it reduce user delays experienced during road repairs. TDOT wanted a quicker way to backfill trenches after making road cuts to repair pipes buried under roads.

Pouring ZOOM into a test trench.

“The challenge was to create what the industry calls ‘rapid-set, flowable fill,’ a substance that can be poured into the trench that sets quickly so you can pave over it and get the road open again for traffic,” explains L.K. Crouch, the professor of Civil and Environmental Engineering who supervised the project.

“It looks a lot like pancake batter,” he says. “That’s part of the appeal because it doesn’t need compacting, which takes more time and manpower.”

Although initially pourable like batter, ZOOM rapidly hardens, supports foot traffic in about two hours and vehicular traffic within three-to-six hours depending on the ambient temperature. It's inexpensive and uses commonly available materials.

ZOOM cures quickly, a key element of its success.

By using ZOOM, road workers avoid having to compact soil and crushed rock into the trench. Compacting a trench is slow, often dangerous, work because rock and soil are not stable and can collapse on workers.

Alan Sparkman, executive director of the Tennessee Concrete Association, says that unlike gravel that settles, ZOOM gains strength to hold pavement up, eliminating the previously inevitable “reverse speed bump” driver experience.

“As an industry representative, this is what we need,” says Sparkman. “What we liked about whole process is that Tennessee Tech was able to take the concept or idea, generate data and come up with a product that met a specific industry need.”

ZOOM was used to repair Robertson Road in Nashville on a busy Memorial Day weekend, and the results were as good as predicted.

“This is best road cut I’ve ever seen,” says Ross Allen of Metro Ready Mix. “It’s performed as advertised, and a ditch has not formed where the repair was made.”

The new composition allowed TDOT to add guidelines to incorporate ZOOM into its operating standards.

“Our specifications for flowable fill weren’t complete until we worked with Crouch and Tennessee Tech on ZOOM,” says Brian Egan, TDOT’s assistant director of materials and tests. “ZOOM was the answer to the need we had for specific applications.”

Although traffic user delays are annoying and time consuming, an upcoming version of ZOOM may hold even more importance to the nation’s military. This rapid repair material is ideal when airfields need a quick repair.

Crouch says recent results that will be further tested this summer promise an even faster set up time than the original ZOOM.