A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Retrofit of Existing Reinforced Concrete Bridges with Fiber Reinforced Polymer Composites
The first part of the reported research examined the performance of four 76-year, deteriorated reinforced concrete beams (which were removed from an existing bridge slated for reconstruction) retrofitted with external carbon FRP (CFRP) post-tensioning rods, bonded CFRP plates, bonded CFRP fabrics, and bonded CFRP plates with mechanical anchors, respectively. The various FRP systems studied in this research produced different failure modes and strength gains. Despite extensive deterioration and age of the beams, the retrofitted beams could develop and exceed the expected capacity computed based on available design guides. For cases where guidelines were not available, simple, yet effective, methods were developed to establish the capacity of the retrofitted beams. In the second part of the reported research, a 45-year old, three-span reinforced concrete slab bridge with insufficient capacity was retrofitted with 76.2 and 127-mm wide bonded carbon fiber reinforced polymer (FRP) plates, 102-mm wide bonded carbon FRP plates with mechanical anchors at the ends, and bonded carbon FRP fabrics. The use of four systems in one bridge provided an opportunity to evaluate field installation issues, and to examine the long-term performance of each system under identical traffic and environmental conditions. Using controlled truckload tests, the response of the bridge before retrofitting, shortly after retrofitting, and after one year of service was measured. The stiffness of the FRP systems was small in comparison to the stiffness of the bridge deck, and accordingly the measured deflections did not noticeably change after retrofitting. The measured strains suggest participation of the FRP systems, and more importantly the strength of the retrofitted bridge was increased. A detailed three-dimensional finite element model of the original and retrofitted bridge was developed and calibrated based on the measured defections. The model was used to more accurately predict the demands needed for computing the rating factors. The addition of FRP plates and fabrics led to a 22% increase in the rating factor and corresponding load limits. During a one-year period, traffic loading and environmental exposure did not apparently affect the performance of the FRP systems. In view of the increased capacity and performance of the FRP systems, load limits were removed and normal traffic was resumed. Future tests are necessary to monitor the long-term behavior of the FRP systems.
Retrofit of Existing Reinforced Concrete Bridges with Fiber Reinforced Polymer Composites
The first part of the reported research examined the performance of four 76-year, deteriorated reinforced concrete beams (which were removed from an existing bridge slated for reconstruction) retrofitted with external carbon FRP (CFRP) post-tensioning rods, bonded CFRP plates, bonded CFRP fabrics, and bonded CFRP plates with mechanical anchors, respectively. The various FRP systems studied in this research produced different failure modes and strength gains. Despite extensive deterioration and age of the beams, the retrofitted beams could develop and exceed the expected capacity computed based on available design guides. For cases where guidelines were not available, simple, yet effective, methods were developed to establish the capacity of the retrofitted beams. In the second part of the reported research, a 45-year old, three-span reinforced concrete slab bridge with insufficient capacity was retrofitted with 76.2 and 127-mm wide bonded carbon fiber reinforced polymer (FRP) plates, 102-mm wide bonded carbon FRP plates with mechanical anchors at the ends, and bonded carbon FRP fabrics. The use of four systems in one bridge provided an opportunity to evaluate field installation issues, and to examine the long-term performance of each system under identical traffic and environmental conditions. Using controlled truckload tests, the response of the bridge before retrofitting, shortly after retrofitting, and after one year of service was measured. The stiffness of the FRP systems was small in comparison to the stiffness of the bridge deck, and accordingly the measured deflections did not noticeably change after retrofitting. The measured strains suggest participation of the FRP systems, and more importantly the strength of the retrofitted bridge was increased. A detailed three-dimensional finite element model of the original and retrofitted bridge was developed and calibrated based on the measured defections. The model was used to more accurately predict the demands needed for computing the rating factors. The addition of FRP plates and fabrics led to a 22% increase in the rating factor and corresponding load limits. During a one-year period, traffic loading and environmental exposure did not apparently affect the performance of the FRP systems. In view of the increased capacity and performance of the FRP systems, load limits were removed and normal traffic was resumed. Future tests are necessary to monitor the long-term behavior of the FRP systems.
Retrofit of Existing Reinforced Concrete Bridges with Fiber Reinforced Polymer Composites
B. M. Shahrooz (author) / S. Boy (author)
2001
77 pages
Report
No indication
English
RETROFIT OF REINFORCED CONCRETE BRIDGES WITH CARBON FIBER REINFORCED POLYMER COMPOSITES
| British Library Conference Proceedings | 1999
| British Library Conference Proceedings | 2007
| British Library Online Contents | 2007