CoSci students use plastic bottles to increase concrete's pliability

Construction science students at Texas A&M are getting a first-hand look at how plastic bottles could someday help save concrete buildings from catastrophic failure in an earthquake.

Led by Nancy Holland, associate professor of construction science, they’re doing research at the College of Architecture’s digital fabrication facility at the Riverside Campus, assisted by John Nichols, associate professor of construction science.

“The idea is to overcome the ductility, or pliability, problems that concrete buildings have,” said Holland.

They’re starting from scratch, creating a mix of concrete, aggregate and plastic made from ordinary, shredded plastic bottles and making square beams approximately a foot long and 3 inches thick.

Student are using a three-point bending test with equipment at the digital fabrication facility on a variety of mixes using to see how they affect the ductility of the concrete blocks they’ve made. "For now, what we're looking for is crack control in footpaths," said Holland.

The tests employ standards established by ASTM International, formerly known as the American Society for Testing and Materials.

“When the concrete splits and the plastic is across the crack it stretches. Instead of snapping, it bends,” said Nichols.

The idea’s development, he said, would be especially welcome in the third world, where steel is expensive but plastic bottles are plentiful.

“The exercise," Holland said, "is helping students learn how to make concrete and see real research on basic materials.