A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Behavior of prestressed concrete strengthened with various CFPR systems subjected to fatigue loading
Many prestressed concrete bridges are in need of upgrades to increase their posted capacities. The use of carbon fiber-reinforced polymer (CFRP) materials is gaining credibility as a strengthening option for reinforced concrete, yet few studies have been undertaken to determine their effectiveness for strengthening prestressed concrete. The effect of the CFRP strengthening on the induced fatigue stress ratio in the prestressing strand during service loading conditions is not well defined. This paper explores the fatigue behavior of prestressed concrete bridge girders strengthened with CFRP through examining the behavior of seven decommissioned 9.14 m (30 ft) girders strengthened with various CFRP systems including near-surface-mounted bars and strips, and externally bonded strips and sheets. Various levels of strengthening, prestressing configurations, and fatigue loading range are examined. The experimental results are used to provide recommendations on the effectiveness of each strengthening configuration. Test results show that CFRP strengthening can reduce crack widths, crack spacing, and the induced stress ratio in the prestressing strands under service loading conditions. It is recommended to keep the prestressing strand stress ratio under the increased service loading below the value of 5 % for straight prestressing strands, and 3 % for harped prestressing strands. A design example is presented to illustrate the proposed design guidelines in determining the level of CFRP strengthening. The design considers the behavior of the strengthened girder at various service and ultimate limit states.
Behavior of prestressed concrete strengthened with various CFPR systems subjected to fatigue loading
Many prestressed concrete bridges are in need of upgrades to increase their posted capacities. The use of carbon fiber-reinforced polymer (CFRP) materials is gaining credibility as a strengthening option for reinforced concrete, yet few studies have been undertaken to determine their effectiveness for strengthening prestressed concrete. The effect of the CFRP strengthening on the induced fatigue stress ratio in the prestressing strand during service loading conditions is not well defined. This paper explores the fatigue behavior of prestressed concrete bridge girders strengthened with CFRP through examining the behavior of seven decommissioned 9.14 m (30 ft) girders strengthened with various CFRP systems including near-surface-mounted bars and strips, and externally bonded strips and sheets. Various levels of strengthening, prestressing configurations, and fatigue loading range are examined. The experimental results are used to provide recommendations on the effectiveness of each strengthening configuration. Test results show that CFRP strengthening can reduce crack widths, crack spacing, and the induced stress ratio in the prestressing strands under service loading conditions. It is recommended to keep the prestressing strand stress ratio under the increased service loading below the value of 5 % for straight prestressing strands, and 3 % for harped prestressing strands. A design example is presented to illustrate the proposed design guidelines in determining the level of CFRP strengthening. The design considers the behavior of the strengthened girder at various service and ultimate limit states.
Behavior of prestressed concrete strengthened with various CFPR systems subjected to fatigue loading
Das Verhalten von mit verschiedenen CFPR-Systemen verstärktem Spannbeton unter Dauerbeanspruchung
Rosenboom, Owen (author) / Rizkalla, Sami (author)
Journal of Composites for Construction ; 10 ; 492-502
2006
11 Seiten, 9 Bilder, 1 Tabelle, 35 Quellen
Article (Journal)
English
Behavior of Prestressed Concrete Strengthened with Various CFRP Systems Subjected to Fatigue Loading
| British Library Online Contents | 2006
Behavior of Prestressed Concrete Strengthened with Various CFRP Systems Subjected to Fatigue Loading
| Online Contents | 2006
| British Library Conference Proceedings | 2005
| British Library Conference Proceedings | 2005
Flexural behavior of aged prestressed concrete girders strengthened with various FRP systems
| British Library Conference Proceedings | 2007