Repair Of Impact Damaged Prestressed Concrete Girders Using Carbon Fiber Reinforced Polymers

Download or read book Repair of Impact Damaged Prestressed Concrete Girders Using Carbon Fiber Reinforced Polymers written by John David Rhodes and published by . This book was released on 2000 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every year several prestressed concrete (P/C) girder bridges are damaged by overheight vehicles. Traditional P/C girder repair strategies include beam replacement, internal strand splices, external post-tensioning, and welded steel jackets. Unfortunately, these types of repairs are both labor intensive and vulnerable to future corrosion. One possible alternative to these traditional repair techniques is to repair/strengthen impact damaged P/C girders with carbon fiber reinforced polymers (CFRP). These types of materials have the advantage of large strength/weight ratios, excellent corrosion/fatigue properties, and are relatively simple to install. This report describes the experimental results from three full-sized P/C beams that were intentionally damaged to simulate vehicle impacts, repaired, and tested. Damage consisted of removing concrete from the bottom flange and severing a number of prestressing strands. The beams were strengthened/repaired by patching the bottom flange and installing multiple layers unidirectional CFRP to restore the original flexural capacity. CFRP fibers were also used in the transverse direction to help confine the patch material and to prevent premature debonding of the longitudinal sheets. Service level and ultimate load tests were conducted to determine the effectiveness of CFRP strengthening system. A theoretical analysis of the strengthened/repaired beams was also completed. In addition to the full-size beams, a number of smaller specimens were also used to address durability and environmental concerns related to the use CFRP on bridge structures.