Although these issues may seem unrelated, composite materials research at the University is addressing both concerns. Composites are materials that combine two or more components to yield characteristics superior to any one of the individual constituents. Strong and lightweight, composites offer resistance to corrosion and chemical attack. All of these characteristics make composites useful to civil engineers for construction and infrastructure rehabilitation. Using concrete and steel to repair a degraded structure like a bridge deck can actually cause its collapse, and traditional repair methods usually require closing the structure to traffic.
Rehabilitation using composites is potentially quick and can be done with the structures kept open.
Karbhari's team is adopting several approaches. Crumbling concrete columns and piers can be wrapped with fiber-reinforced composites, a technique advanced by the Japanese. In this area, Karbhari's team has obtained good results with the use of a unique, resin-infusion process that results in performance improvements of as high as 100 percent. They have already shown that the use of combinations of two or more fiber types can offer capabilities beyond those of reinforced concrete and steel. In a project supported by the Delaware Department of Transportation, Karbhari and civil engineering colleagues are studying the use of composite plates to rehabilitate cracked bridge girders.