题名: |
Evaluating Fiber Reinforced Polymer Repair Method for Cracked Prestressed Concrete Bridge Members Subjected to Repeated Loadings (Phase 2). Final rept. Sep 01-May 07. |
作者: |
Larson-K.H.; Rasheed-H.A.; Peterman-R.J. |
关键词: |
*Bridges-(Structures; *Fatigue-performance; *Fiber-reinforced-polymer-(FRP; *Bridge-repairs; *Loadings-.;Nonlinear-analysis; Concrete-T-beams; Cracked-; Strengthening-; Prestressed-. |
摘要: |
This research is intended to investigate the fatigue performance of pre-cracked prestressed concrete T-beams for a specific strand stress range and its relationship to the level of strengthening gained. Controlling the strand stress range is accomplished by iterative cycles of nonlinear analysis to determine the amount of external carbon Fiber Reinforced Polymer (FRP) reinforcement needed for that purpose. Five pre-tensioned prestressed concrete T-beams were cast at a prestressed concrete plant in Newton, Kansas. Beam 1 was tested under static loading up to failure as a control specimen. Beams 2 and 3 were strengthened with Carbon Fiber Reinforced Polymer (CFRP) to have a design stress range of 18 ksi under service load condition. Beams 4 and 5 were also strengthened to have a higher stress range of 36 ksi. Beams 2 and 4 were loaded monotonically to failure while Beams 3 and 5 were cycled over a million times before they were brought to failure. The design yielded one layer of flexural CFRP wrapped around the web sides up to 2.25 from the bottom for the 18 ksi stress range design. It also resulted in two layers of longitudinal CFRP for the 36 ksi stress range design, the inner layer wrapped around the web sides up to 0.5 and the outer layer went up 3 on the web sides. External CFRP stirrups were used to prevent the longitudinal CFRP from premature separation. Beams 2 and 4 successfully reached their target strengthening design levels and Beams 3 and 5 performed very well in fatigue. |
报告类型: |
科技报告 |