Strengthening structures with externally prestressed tendons: laboratory tests
2005 (English)Report (Other academic)
The need of rehabilitation and strengthening of concrete structures has increased considerably the last decade. The causes for repair and/or strengthening can be many, but normally change of use, increased demands on the structure, errors in the design or/and construction phase or accidents are governing. Many methods to repair or/and strengthen concrete structures exists such as concrete overlays, shotcrete, external prestressed cables etc. This report presents laboratory tests where concrete T-beams with a length of 6 meters have been strengthened. External prestressed cables and epoxy bonded CFRP (Carbon Fibre Reinforced Polymer) rods have been used. Three beams had external tendons, two with steel tendons and one with CFRP. Three beams were strengthened with epoxy bonded CFRP Near Surface Mounted Rods (NSMR). On one of those beams the rods were prestressed before bonding. One beam hade post-stressed internal steel tendons and also a non strengthened reference beam was tested. The results showed that all tested strengthening techniques increased the load carrying capacity of the beams. The beam with external tendons of CFRP obtained problems with the anchor and could therefore not be prestressed to the desired level, which also then had effect on the strengthening level. The other strengthened beams recorded for a strengthening level from 81% to 107% depending on the technique used. The tests scores show that prestressing is a very effective strengthening method to increase the load carrying capacity of existing concrete beams.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2005. , 42 p.
Technical report / Luleå University of Technology, ISSN 1402-1536 ; 2005:07
Research subject Structural Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-24911Local ID: d05451b0-2804-11dd-8187-000ea68e967bOAI: oai:DiVA.org:ltu-24911DiVA: diva2:997963
Godkänd; 2005; 20080522 (ysko)2016-09-292016-09-29Bibliographically approved