AN EXPERIMENTAL STUDY OF THE STRENGTHENING OF REINFORCED CONCRETE BEAMS USING PRESTRESSED CARBON COMPOSITE PLATES

Concrete structures deteriorate for various reasons and upgrading has been achieved for over twenty years by bonding steel plates using epoxy resins. Disadvantages of this method include transporting, handling and installing heavy plates and corrosion of the plates. The use of composite materials overcomes these problems and provides equally satisfactory solutions. The rehabilitation of concrete structures represents a large demand for efficient strengthening methods and composite materials are well suited to this application. Reinforced concrete beams of 1.0m and 4.5m lengths were tested in four point bending after strengthening them with externally bonded carbon fibre reinforced polymer plates. The plates were bonded without prestress and with prestress levels ranging from 25% to 50% of the plate strength. The ultimate capacities of the plated non-prestressed beams were significantly higher than those of the unplated members and plate prestress brought about further strengthening. The non-prestressed beams failed by concrete fracture in the cover to the internal rebars, while most of the prestressed beams failed by plate fracture. The plate prestress prevented cracking of the adhesive layer, a phenomenon associated with shear cracking in the concrete. The plates of prestressed beams have an initial tensile strain before external load is applied and this brings about a relatively high beam stiffness. It is found that prestressed plates are utilised more efficiently than non-prestressed plates since a given plate strain is associated with a lower structural deformation in a prestressed member. Prestressing lowers the position of the neutral axis so more of the concrete section is loaded in compression, making more efficient use of the concrete. For the covering abstract see ITRD E111699.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0947644320
• Corporate Authors:

  ENGINEERING TECHNICS PRESS

  46 CLUNY GARDENS
  EDINBURGH,   United Kingdom  EH10 6BN
• Authors:
  • GARDEN, H N
  • HOLLAWAY, L
• Conference:
  • PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON STRUCTURAL FAULTS AND REPAIR, 8 JULY 1997. VOLUME 2: CONCRETE AND COMPOSITES
• Publication Date: 1997

Language

• English

Media Info

• Features: References;
• Pagination: p. 191-9

Subject/Index Terms

• TRT Terms: Beams; Carbon; Conferences; Fibers; Material reinforcement; Polymers; Prestressing; Reinforced concrete; Reinforcing materials
• ITRD Terms: 3472: Beam; 7158: Carbon; 8525: Conference; 4557: Fibre; 7482: Polymer; 4777: Prestressing; 4794: Reinforced concrete; 3471: Reinforcement (in mater)
• Subject Areas: Construction; Data and Information Technology;

Filing Info

• Accession Number: 00922440
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0-947644-32-0
• Files: ITRD
• Created Date: Apr 2 2002 12:00AM