Tests investigate CFRP’s ability to protect against explosives

A researcher at the University of Missouri is working with the US Army to test a method of retrofitting buildings to protect them in the case of a terrorist attack.

Sarah Orton, an assistant professor of civil engineering at the University of Missouri’s College of Engineering, has focused on using carbon-fibre-reinforced polymer (CFRP), a fabric that can carry 143,000 pounds of force per square inch and has previously been used to strengthen buildings in earthquake zones.

To protect a building from an extreme event, CFRP can be used to increase the bending capacity of walls or columns. Previously, Orton invented an anchor that can be embedded in the column or joint to make CFRP more effective. In that work, Orton found that the anchors allowed the CFRP to reach its full tension strength rather than separating from the concrete at only about half its strength.

To study the effectiveness of different ways of applying CFRP, Orton worked with the US Army Engineer Research and Development Center (ERDC) to detonate explosives near CFRP-reinforced concrete slabs.

She found that CFRP, when layered and anchored, provided a significant amount of protection. However, she said that applying additional protection to the front of the concrete slab, such as a steel plate, would enhance the slab’s performance further.

But, Orton said, at present, the high cost of the material — approximately $30 (£18) per square foot — has kept it from being widely implemented in areas that are not prone to earthquakes.