Grant Could Help Crack Down on Concrete Deficiencies

Senior Walk, an integral part of the University of Arkansas campus, spans five miles of pavement etched with graduates’ names reaching back to 1876.

As the university’s oldest tradition, and as the only Senior Walk in the country, preservation of the pavement is vital. When walking around campus, however, it is hard not to notice the cracks and wear that stretch along the pathways.

Now Senior Walk and other future campus concrete projects might benefit from research supported by a recent $500,000 gift from the Oklahoma/Arkansas chapter of the American Concrete Pavement Association. The intent is for researchers to study methods of creating stronger, more cost efficient concrete.

The half-million-dollar pledge will make the U of A a national leader in concrete pavement research, said Cameron Murray, assistant professor in the Department of Civil Engineering. It also supports Campaign Arkansas, the university’s $1.25 billion capital campaign to advance academic opportunity.

This gift comes at an appropriate time; many noticeable sections of campus pavement could use a touch up, including portions of Senior Walk that have been mauled by construction or simply become worn over time.

“We have cracking sometimes. Concrete cracks,” Mike Johnson, the associate vice chancellor for facilities management, said. “We try to put in joints so it cracks where we want it to crack. We’re quasi-successful.”

New concrete is always tested when it is placed, Johnson said.

“They’ll take cylinders and they’ll break cylinders at 7, 14 and 28 days and look at the compression to make sure we actually have what we paid for,” Johnson said.

The association gift will be provided in five yearly installments and will support teaching and research activities in the concrete laboratory at the Engineering Research Center, Murray said.

“Early on it looks like we will mostly use the money to fund graduate students who will do work related to concrete pavements,” Murray said. “In particular we will be looking at ways to make more efficient, more cost effective concrete pavements.”

More cost efficient concrete could make it easier for the university to make some quick fixes around campus.

They can approach the matter of more efficient pavements by either selecting more cost effective combinations of ingredients for concrete or by proposing different designs to the pavement, Murray said.

“For example, we can look at how the ‘structure’ of the pavement is designed, trying to use a thinner section that will be more cost effective,” Murray said.

Concrete is designed for its specific application, said Daniel Clairmont, the director of engineering and construction.

“Foundations, patios, sidewalks and roads are all different strengths and different thicknesses,” Clairmont said. “If it is expected to carry heavy loads, it would generally be thicker and stronger.”

These differences in the pavement around campus might explain why some portions look pristine and have held up well over the years, while adjacent areas are cracked or otherwise damaged.

“Senior walk is a totally separate formula and process because it has to be a very smooth surface so we can glue down the rubber stencils and do the sand blasting,” Johnson said. “So it’s higher strength; we pay more attention on how it’s finished and that type of thing.”

The quality of the base on which the concrete is poured also plays a factor in its longevity, Clairmont said.

“A poorly compacted base, or if it is not protected from water infiltration and erosion, will almost guarantee the concrete will crack and fail,” Clairmont said.

As graduating classes are added to Senior Walk, alumni will appreciate any effort to preserve the names that have been engraved for decades.

“Concrete is pretty simple,” Johnson said.