A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Development and Assessment of a Mechanical Strengthening System for Post-tensioned Concrete Bridge Cantilever Wings Using Post-tensioned CFRP Rods
This paper presents the development and experimental assessment of a mechanical strengthening system using post-tensioned (PT) carbon fiber reinforced polymer (CFRP) rods for the rehabilitation of post-tensioned concrete bridge cantilever wings. CFRP rods were selected as a direct parallel to PT steel bars owing to CFRP’s superior fatigue, corrosion resistance, and lightweight properties as a composite material. The mechanical strengthening system is a metal anchor comprised of a stainless steel barrel and split aluminum wedges in direct contact with a CFRP rod. The system strictly relies on friction for load-bearing capacity with no adhesives required. The developed CFRP mechanical anchorage system is assessed experimentally as part of a broader experimental program seeking to adequately transfer the CFRP post-tensioning force through bearing at anchorage ends to strengthen PT concrete bridge cantilever wing specimens that exhibit deterioration. The CFRP rods for strengthening will be embedded in near-surface-mounted (NSM) grooves in the negative moment region of the experimental PT concrete bridge cantilever wing specimens. The anchor features a contoured longitudinal profile consisting of a 1650 mm circular radius to minimize the stress concentrators at the loading end of the anchor, pushing the stress toward the back of the anchor. The anchor also features a competitive 80 mm in length stainless steel barrel and 80 mm in length aluminum wedge core. Seven specimens in total were carried out for the experimental assessment of the anchorage system. All prepared specimens measured 1.8 m in total length with a 1.5 m CFRP rod free gauge length in-between the ends of the anchors. Two specimens as proof of concept anchorage testing were carried out with no pre-setting load to observe the behavior of the design concept during loose wedge conditions. Subsequently, anchorage static testing was carried out with five prepared specimens. Two distinct pre-setting loads were selected to induce initial contact pressure between the wedges and the CFRP rod to reduce slippage. Three specimens were pre-set at 80 kN and two specimens were pre-set at 100 kN before tensioning. The average ultimate capacity of the anchorage system was 97.6 kN, yielding a system efficacy of 63.4% against a guaranteed CFRP tensile strength of 154 kN. Adhering to the Canadian Highway Bridge Design Code, S6-19, the CFRP rods will be post-tensioned up to an effective jacking force of 50 kN at transfer due to the anchorage effect on the CFRP rod.
Development and Assessment of a Mechanical Strengthening System for Post-tensioned Concrete Bridge Cantilever Wings Using Post-tensioned CFRP Rods
This paper presents the development and experimental assessment of a mechanical strengthening system using post-tensioned (PT) carbon fiber reinforced polymer (CFRP) rods for the rehabilitation of post-tensioned concrete bridge cantilever wings. CFRP rods were selected as a direct parallel to PT steel bars owing to CFRP’s superior fatigue, corrosion resistance, and lightweight properties as a composite material. The mechanical strengthening system is a metal anchor comprised of a stainless steel barrel and split aluminum wedges in direct contact with a CFRP rod. The system strictly relies on friction for load-bearing capacity with no adhesives required. The developed CFRP mechanical anchorage system is assessed experimentally as part of a broader experimental program seeking to adequately transfer the CFRP post-tensioning force through bearing at anchorage ends to strengthen PT concrete bridge cantilever wing specimens that exhibit deterioration. The CFRP rods for strengthening will be embedded in near-surface-mounted (NSM) grooves in the negative moment region of the experimental PT concrete bridge cantilever wing specimens. The anchor features a contoured longitudinal profile consisting of a 1650 mm circular radius to minimize the stress concentrators at the loading end of the anchor, pushing the stress toward the back of the anchor. The anchor also features a competitive 80 mm in length stainless steel barrel and 80 mm in length aluminum wedge core. Seven specimens in total were carried out for the experimental assessment of the anchorage system. All prepared specimens measured 1.8 m in total length with a 1.5 m CFRP rod free gauge length in-between the ends of the anchors. Two specimens as proof of concept anchorage testing were carried out with no pre-setting load to observe the behavior of the design concept during loose wedge conditions. Subsequently, anchorage static testing was carried out with five prepared specimens. Two distinct pre-setting loads were selected to induce initial contact pressure between the wedges and the CFRP rod to reduce slippage. Three specimens were pre-set at 80 kN and two specimens were pre-set at 100 kN before tensioning. The average ultimate capacity of the anchorage system was 97.6 kN, yielding a system efficacy of 63.4% against a guaranteed CFRP tensile strength of 154 kN. Adhering to the Canadian Highway Bridge Design Code, S6-19, the CFRP rods will be post-tensioned up to an effective jacking force of 50 kN at transfer due to the anchorage effect on the CFRP rod.
Development and Assessment of a Mechanical Strengthening System for Post-tensioned Concrete Bridge Cantilever Wings Using Post-tensioned CFRP Rods
Lecture Notes in Civil Engineering
Gupta, Rishi (editor) / Sun, Min (editor) / Brzev, Svetlana (editor) / Alam, M. Shahria (editor) / Ng, Kelvin Tsun Wai (editor) / Li, Jianbing (editor) / El Damatty, Ashraf (editor) / Lim, Clark (editor) / Shahrstan, Faraj (author) / Sadeghian, Pedram (author)
Canadian Society of Civil Engineering Annual Conference ; 2022 ; Whistler, BC, BC, Canada
Proceedings of the Canadian Society of Civil Engineering Annual Conference 2022 ; Chapter: 10 ; 133-149
2024-02-06
17 pages
Article/Chapter (Book)
Electronic Resource
English
Carbon fiber-reinforced polymers (CFRP) , Wedge-barrel anchor , Post-tensioning , NSM rehabilitation , Concrete bridge cantilever strengthening Engineering , Building Construction and Design , Geoengineering, Foundations, Hydraulics , Transportation Technology and Traffic Engineering , Environment, general
Strengthening Precracked Post-tensioned Concrete Beams with CFRP Composites
| Springer Verlag | 2024
Repair of reinforced concrete deep beams using post-tensioned CFRP rods
| Tema Archive | 2015
Strengthening of Steel Silos with Post-Tensioned CFRP Laminates
| British Library Conference Proceedings | 2003
SP-275-60: Prestressed Concrete Girder Repair with CFRP Post-Tensioned Rods
| British Library Conference Proceedings | 2011