Prestressed CFRP for Strengthening of Reinforced Concrete Structures: Recent Developments at Empa, Switzerland
- 1 April 2011
- journal article
- Published by American Society of Civil Engineers (ASCE) in Journal of Composites for Construction
- Vol. 15 (2), 194-205
- https://doi.org/10.1061/(asce)cc.1943-5614.0000125
Abstract
In civil engineering today, only 20 to 30% of the strength of carbon-fiber-reinforced polymer (CFRP) strips is used when they are applied as externally bonded strips for flexural and shear strengthening or in confinement of reinforced concrete (RC) structural elements. The strips are better used when the CFRP material is prestressed. This offers several advantages, including reduced crack widths, reduced deflections, reduced stress in the internal steel, and possibly increased fatigue resistance. In this paper, recent developments in the field of RC strengthening using prestressed CFRP are presented. The paper focuses on developments in flexural and shear strengthening and column confinement made at the Swiss Federal Laboratory for Materials Testing and Research (Empa). Several innovative ideas have been successfully realized in the laboratory. For example, a gradient prestressing technique without end anchorage plates was developed and successfully applied to a 17 m RC bridge girder. A confinement technique using nonlaminated thermoplastic CFRP straps was also investigated and applied to 2 m high RC columns. These results are encouraging, although practical and theoretical problems remain to be solved before these techniques can be fully applied.Keywords
This publication has 35 references indexed in Scilit:
- The behavior of concrete cylinders confined by shape memory alloy wiresSmart Materials and Structures, 2008
- Nonlinear FE analysis of cracks in tension and shearMagazine of Concrete Research, 2007
- Applications of shape memory alloys in civil engineering structures - Overview, limits and new ideasMaterials and Structures, 2005
- Flexural behaviour of concrete beams strengthened with prestressed carbon fibre reinforced polymer sheets subjected to sustained loading and low temperatureCanadian Journal of Civil Engineering, 2004
- RC column strengthening by lateral pre-tensioning of FRPConstruction and Building Materials, 2003
- Prestressed and non-prestressed CFRP sheet strengthening: damaged continuous reinforced concrete beamsInternational Journal of Materials and Product Technology, 2003
- Einsatz vorgespannter Kohlefaser-Lamellen als OberflächenspanngliederBeton- und Stahlbetonbau, 2001
- Vorgespannte CFK‐Lamellen zur Verstärkung von BauwerkenBeton- und Stahlbetonbau, 2001
- The flexural rehabilitation of reinforced concrete beams by the use of prestressed advanced composite platesComposites Science and Technology, 1998
- Design of seismic retrofit measures for concrete and masonry structuresConstruction and Building Materials, 1995