A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Evaluation of novel combined CFRP-steel retrofit for repairing distortion-induced fatigue
Abstract Distortion-induced fatigue damage at crossframe-to girder connections affects many steel bridges built before the mid-1980s. This type of damage is associated with a prevalent detailing practice at the time which avoided welding connection plates to girder flanges to avoid fatigue cracks. The lack of connectivity and out-of-plane motion of the crossframe produce a flexible gap region in the girder web where fatigue cracks often develop, requiring frequent inspections, costly maintenance, and repairs. This paper presents a study evaluating the use of CFRP in conjunction with steel sections to repair complex patterns of distortion-induced fatigue cracks in steel bridge web gaps, without the need for bolting to the flange or concrete deck removal. A steel girder-to-crossframe subassembly was tested in distortion-induced fatigue to evaluate the performance of the retrofit measure. Realistic crack patterns were introduced by applying fatigue loading, and the efficacy of the repair method was evaluated by monitoring crack growth with the repair in place. Twelve test trials were performed: five in the unretrofitted condition to propagate the cracks, and seven in the retrofitted condition to evaluate performance of the repair. The study evaluated multiple crack patterns, different configurations of the retrofit, presence or absence of mechanical anchorage to the flange, footprint of the CFRP relative to the steel retrofit elements, and different surfaces connected by the CFRP. The results showed that the combined CFRP-steel retrofit measure was effective in preventing distortion-induced fatigue crack initiation and propagation.
Graphical abstract Display Omitted
Highlights A novel combined CFRP-steel retrofit enables repair of distortion-induced fatigue cracks. The retrofit can be applied without requiring bridge deck removal. The retrofit increases connection stiffness and reduces displacements in the web gap region. The retrofit halted crack propagation of distortion-induced fatigue cracks in rigorous testing. No debonding of the retrofit was observed in any of the fatigue trials or configurations studied.
Evaluation of novel combined CFRP-steel retrofit for repairing distortion-induced fatigue
Abstract Distortion-induced fatigue damage at crossframe-to girder connections affects many steel bridges built before the mid-1980s. This type of damage is associated with a prevalent detailing practice at the time which avoided welding connection plates to girder flanges to avoid fatigue cracks. The lack of connectivity and out-of-plane motion of the crossframe produce a flexible gap region in the girder web where fatigue cracks often develop, requiring frequent inspections, costly maintenance, and repairs. This paper presents a study evaluating the use of CFRP in conjunction with steel sections to repair complex patterns of distortion-induced fatigue cracks in steel bridge web gaps, without the need for bolting to the flange or concrete deck removal. A steel girder-to-crossframe subassembly was tested in distortion-induced fatigue to evaluate the performance of the retrofit measure. Realistic crack patterns were introduced by applying fatigue loading, and the efficacy of the repair method was evaluated by monitoring crack growth with the repair in place. Twelve test trials were performed: five in the unretrofitted condition to propagate the cracks, and seven in the retrofitted condition to evaluate performance of the repair. The study evaluated multiple crack patterns, different configurations of the retrofit, presence or absence of mechanical anchorage to the flange, footprint of the CFRP relative to the steel retrofit elements, and different surfaces connected by the CFRP. The results showed that the combined CFRP-steel retrofit measure was effective in preventing distortion-induced fatigue crack initiation and propagation.
Graphical abstract Display Omitted
Highlights A novel combined CFRP-steel retrofit enables repair of distortion-induced fatigue cracks. The retrofit can be applied without requiring bridge deck removal. The retrofit increases connection stiffness and reduces displacements in the web gap region. The retrofit halted crack propagation of distortion-induced fatigue cracks in rigorous testing. No debonding of the retrofit was observed in any of the fatigue trials or configurations studied.
Evaluation of novel combined CFRP-steel retrofit for repairing distortion-induced fatigue
Al-Salih, Hayder (author) / Bennett, Caroline (author) / Matamoros, Adolfo (author)
2021-03-07
Article (Journal)
Electronic Resource
English
Repairing Distortion-Induced Fatigue in Steel Bridges Using a CFRP-Steel Retrofit
| British Library Conference Proceedings | 2020
| British Library Online Contents | 2014