Featured Project: CatStrong Biaxial Hemp Wrap
The deteriorated wooden pier-piles on the KY 32 Bridge over Blaine Creek in Lawrence County required repair or replacement in order to keep the bridge in service. KTC’s Structures group assisted the District 12 Bridge Crew with a retrofit solution that deployed an experimental hemp fabric to apply to the damaged timber. The bridge is the first Civil Engineering structure in the world to use hemp as a construction material. UK students produced the CatStrong Biaxial Hemp Wrap (BHW) in the laboratory by applying a two-part epoxy resin to the fabric. Hemp is a natural fiber and an agricultural product of Kentucky, and has the advantages of being biodegradable and carrying a smaller carbon footprint than synthetic fibers. The Structures Laboratory plans to experiment with plant-based resins instead of epoxy to produce future biodegradable, flexible, lightweight, and re-usable wraps.
Dr. Issam Harik and Dr. Abheetha Peiris received the Prestigious American Concrete Institute (ACI) Design Award for 2021. Go to ACI’s webpage for more information. The award was given at the ACI’s President’s Virtual Reception. Congratulations to Drs. Harik and Peiris!
Approximately 25% of bridges in the United States have been classified as structurally deficient or functionally obsolete. Although the number of deficient bridges has gradually declined over the past 10 years, much work remains to be done, especially with many state transportation agencies that have limited funds for repairing or replacing bridges that are quickly aging beyond their planned service lives. KTC’s Structures group is dedicated to playing a critical role in helping to preserve the nation’s infrastructure. They use the most sophisticated technology and modeling techniques to evaluate and monitor bridges and other structures, and implement novel, high-performance materials to strengthen new and existing structures. The group’s researchers have developed the CatStrong family of products, including CatStrong CRP-XXX, a lightweight carbon fiber reinforced polymer rod panel used to repair deficient bridges, and several varieties of carbon fiber reinforced polymer fabrics and wraps. CatStrong products are designed for quick application, which reduces the cost and labor necessary to complete bridge maintenance projects. The Structures group has worked extensively with the Kentucky Transportation Cabinet, completing over 85 projects on issues ranging from bridge retrofit and bridge replacement, to instrumenting bridges and performing structural health monitoring. Researchers also collaborate with KTC’s Bridge Preservation program and the Pavements, Materials, Geotechnology, and Infrastructure Assessment program to devise holistic solutions to challenging bridge structure problems.
CatStrong: The Composite Revolution
The CatStrong family of products are revolutionary, lightweight carbon fiber reinforced polymer rod panels, fabrics, and wraps used to repair deficient bridges. CatStrong products are designed for faster and more efficient application, reducing labor hours and equipment costs that are typically necessary for bridge maintenance projects. CatStrong rod panels were the first product developed by a joint team of researchers from the Structures Program at The Kentucky Transportation Center (KTC) and the Department of Civil Engineering at the University of Kentucky. The rod panels consist of small diameter carbon fiber rods that can resist up to 195,700 pounds of force per one foot wide section, but only weigh 6.48 ounces per square foot. On bridge structural members that have become deficient over time, CatStrong rod panels are bonded directly to existing reinforced and pre-stressed concrete.
Scroll down to read about KTC projects that feature a lightweight carbon fiber CatStrong product. For specifications and further information about CRP rod panels and the complete line of CatStrong Products, please click here for further information.
Structures – News & Research
Rapid Retrofit & Strengthening of Bridge Components
Rapid repair of damaged or deteriorated concrete bridge components prevents irreversible damage to the bridge’s structural integrity. KTC used newly developed spliced carbon fiber reinforced polymer rod panels (CatStrong CRP) and CatStrong Unidirectional and Triaxial Carbon Fabric (UCF and TCF) to rapidly repair seven selected bridges in Kentucky. Ease of application is the advantage of CRP, requiring only a single worker without the need of heavy construction equipment or tools. Although high performance materials are higher in cost, they reduce overall repair costs compared to other retrofit measures. This is due to the reduction of work days. As a part of this study, KYTC will implement CatStrong Triaxial Carbon Wrap (TCW) and TCF for timber pile repair and strengthening.
Retrofit of Pier Impact Damage using CatStrong UCF and TCF
A semi tractor-trailer truck traveling south on William H. Natcher Parkway veered off the road and impacted a pier-column of the overpass bridge on Elrod Road in Warren County, KY. The impact caused cracking and spalling of concrete in the column as well as cracking on the pier cap. Requiring a rapid retrofit due to the approaching winter weather, KYTC, in cooperation with KTC, proposed the use of CatStrong Uniaxial and Triaxial Carbon Fabric (UCF and TCF) to retrofit the impacted bridge pier-column and pier cap. KTC designed the retrofit, performed analysis, and oversaw the retrofit construction, which was carried out within six work days. Additionally, the bridge remained open to vehicle travel during the repair work.
Click on the links below to learn more:
Load Rating of Bridge Size Culverts
Bridge Load Posting Based on Load Testing (In Progress)
Rapid Pothole Repair in Concrete Bridge Decks (In Progress)