Glass Fiber Reinforced Polymer Strengthening and Evaluation of Railroad Bridge Members

In this work, damaged timber railroad bridge stringers and piles were rehabilitated with glass fiber reinforced polymer (GFRP) composites, and tested. Four timber stringers (152 x 203 x 3560 mm) removed from the field were rehabilitated with GFRP spray lay-up and GFRP wrap vacuum bagging methods. GFRP strengthening increased the shear moduli of the two stringers by 41 and 267%. Rehabilitation and load testing were also performed on an open-deck-timber railroad bridge built during the early 1900s on the South Branch Valley Railroad (SBVR) owned by the West Virginia Department of Transportation (WVDOT) in Moorefield, WV, USA. Specifically, field rehabilitation involved repairing piles using GFRP composite wraps and phenolic formaldehyde adhesives. Static and dynamic tests using a 80 ton locomotive showed that the rehabilitated piles and pile cap showed a 43 and 46% strain reduction, respectively. Dynamic load amplification factor was noted to be almost close to a speed of 24 km/h.