1. Performance of Concrete Railway Ties Prestressed with Basalt FRP
Maen Farhat, Momenur Rahman and Mohsen Issa, Univeristy of Illinois at Chicago Primary Grant Support: NURail Center (U.S. DOT-RITA)
Problem Statement & Motivation
Concrete crossties prestressed with steel strands are subject to corrosion once cracks are initiated. This causes the life cycle of the crossties and their cost effectiveness to be jeopardized.
Basalt FRP is well-known for its resistance to corrosion and high strength performance. A combination of the durability and strength properties of Basalt FRP along with the enhanced performance of precast concrete crossties can greatly reduce the cost of repair and replacement for corroded crossties and boost their cost effectiveness.
Technical Approach
FEA will be used to optimize the geometry and amount of prestressing used in the crossties and examine its performance against ultimate and service rail loads.
Full-scale prototypes will be fabricated and tested at UIC structural laboratories.
Experimental study will be performed to investigate the flexural behavior, cracking and failure modes of concrete crossties under different loading, and setup conditions.
Key Achievements
Basalt FRP bars are practical to replace the steel strands in railway prestressed concrete ties.
Proposed railways ties are resistant to corrosion, durable, and cost effective.
An innovative method has been developed to apply the jacking force to Basalt FRP bars using epoxy filled steel tube. This method allows the BFRP bars to avoid being crushed by the prestressing jack.
Future Goals
Experimental Investigation of the performance of the crosstie subjected to static and cyclic fatigue loading .
Further optimization and calibration of the finite element model.
Implementation of the prestressed concrete crossties with BFRP in elevated structure-bridge applications as well as assessment the track bridge interactions.
Center rail
Stress distribution at service load
Stress distribution at Ultimate load
Rail Seat
Stress distribution at service load
Stress distribution at Ultimate load