Prestressed CFRP Strips for Concrete Bridge Girder Retrofitting: Application and Static Loading Test

Julien Michels,Christoph Czaderski,Renata Kotynia,Yunus Emre Harmanci,Michał Staśkiewicz,Masoud Motavalli

doi:10.1061/(asce)be.1943-5592.0000835

Abstract

AbstractThis paper presents an investigation on the practicability and structural efficiency of prestressed carbon-fiber–reinforced polymer (CFRP) strips with a gradient anchorage in the framework of a bridge-strengthening application in Poland. The nonmechanical anchorage system avoids the installation of metallic bolts and plates, with the exception of a temporary support frame. Two 18.4-m-long large-scale prestressed concrete girders were produced following the drawings of the existing bridge construction. One girder served as a reference, and the second one was strengthened with two prestressed CFRP strips. In this case, the initial negative cambering was leveled out by a layer of dry shotcrete. CFRP strips with a prestrain of 0.58% were applied for flexural upgrading. Both girders with a total length of 18.4 m were finally statically loaded up to failure to assess the strengthening efficiency in flexure of the retrofitting technique used. Tensile failure of the CFRP strips was reached, indicating an ...

Highlights

The application of Carbon Fiber Reinforced Polymer (CFRP) strips in structural strengthening is nowadays well accepted (Meier 1995),(Bakis et al 2002).Their use in the civil engineering domain has drastically increased over the last three decades, several available design codes and recommendations (see,(ACI440.2R-8 2008),(SIA166 2004),(DAfStb 2012), among others) attest their popularity
For the strengthened Girder 2, the ultimate load carrying capacity of 240 kN by tensile failure of the CFRP strips was reached at a concrete compressive strain level at midspan of about 0.15%
It is important to notice that, for both the reference and the strengthened girders, the strain gauges used for capturing the compressive strains on top were mounted after the cable and CFRP strip prestressing

Summary

Introduction

The application of Carbon Fiber Reinforced Polymer (CFRP) strips in structural strengthening is nowadays well accepted (Meier 1995),(Bakis et al 2002).Their use in the civil engineering domain has drastically increased over the last three decades, several available design codes and recommendations (see (fib bulletin14 2001),(ACI440.2R-8 2008),(SIA166 2004),(DAfStb 2012), among others) attest their popularity. For the strengthened Girder 2, the ultimate load carrying capacity of 240 kN by tensile failure of the CFRP strips was reached at a concrete compressive strain level at midspan of about 0.15%.

Results

Conclusion