Kentucky transportation officials unveil new composite product for bridge repair

Dr. Issam Harik's research team has developed a repair panel, called CatStrong CRP-X3, made with small-diameter pultruded carbon fiber rods in an epoxy matrix that can be bonded to structurally-deficient bridges.

The Kentucky Transportation Center’s research team (Lexington, Ky.) has developed a new product called CatStrong CRP-X3. This product consists of Carbon Fiber Reinforced Polymer Rod Panels (CRP) in an epoxy matrix, in a panel form, that can be bonded to existing, structurally deficient reinforced and pre-stressed concrete bridge structural members. The goal of CatStrong CRP-X3 is to decrease bridge repair costs by reducing the number of labor hours typically required to retrofit and repair concrete bridges. 

CatStrong CRP-X3 is produced in the structures laboratory at the University of Kentucky in Lexington. The research team, led by program manager Dr. Issam Harik, developed CatStrong CRP-X3 by using small diameter carbon fiber rods in an epoxy matrix, backed with fiberglass mesh to form a sheet or panel. The rods are manufactured by Diversified Structural Composites (Erlanger, Ky.), and range in diameter from 0.078 to 0.156 inch (2 to 4 mm), depending on the panel strength level (designated by the “X3” in the title). For example, a CatStrong CRP-195 panel with 0.156-inch/4 mm diameter rods can resist more than 195,000 lb of tensile force per one-foot-wide section, while weighing only 6.84 oz/ft2. One square foot of CatStrong CRP-195 provides a strength equivalent to a square foot of A36 steel that is 0.28 inch thick and weighs 183.2 oz (more than 27 times the weight of CatStrong CRP-195).

CatStrong has been installed successfully on four bridges in Kentucky since 2011. During the application of CatStrong CRP-X3, roads remain open, and the impact on the traveling public is minimal. The product's sponsor is the Kentucky Science and Technology Corp., and is supported by the Kentucky Transportation Cabinet and the Federal Highway Administration (FHWA).

“The objective is to reduce repair costs since it can be quickly applied by a single person, thus reducing the labor hours and the construction equipment needed for the job. CatStrong CRP-X3 panels are ideally suited for structures with limited access, such as bridges over a waterway or a deep ravine,” says Harik.