An Innovative Application of FRP Composites in Bridge Strengthening and Repair
Typ
Examensarbete för masterexamen
Program
Publicerad
2019
Författare
Gratwick, Sarah
Raihan Abir, Mohammad
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Abstract
With the gradual increase of vehicle loads in recent years, growing numbers of the
existing bridge stock are becoming structurally obsolete. To tackle this issue, a
bridge strengthening project, named SUREBridge, was initiated in 2015 at Chalmers
University of Technology, with the support of several other partners. This project
proposed an innovative strengthening method; the utilization of pretensioned carbon
fiber reinforced polymer (CFRP) laminates on the base of bridge girders, in combination
with glass fiber reinforced polymer (GFRP) sandwich panels on the top,
to increase the yield and ultimate capacities of existing bridge decks. From experimental
tests, 90 and 160% increases in the bending stiffness and ultimate bending
capacity were found.
This master thesis aims to replicate the experimental results from the four SUREBridge
beams which were tested in the laboratory, through the finite element software
ABAQUS and DIANA. Verification is made through comparisons of the loaddeflection
curves, maximum crack width sizes and crack patterns. A secondary
purpose is to document all approaches and modelling techniques when developing
the finite element models.
To achieve the objective, an extensive literature study was performed to determine
appropriate approaches to include bond-slip between the steel reinforcement and
the concrete beam, as well as the CFRP and the concrete beam. Several sensitivity
analyses were also performed to determine the most appropriate model and material
parameters, to find the best fit to the experimental results.
From the analyses, it was concluded that the inclusion of the full bond-slip curves
between both the concrete and steel, and concrete and CFRP are vital to obtain
accurate results. However, the delamination load can accurately be predicted with
a deviation of less than 2.5% by modelling the steel reinforcement as embedded.
Hence it is concluded that in design, embedded steel can be utilized without significant
losses in accuracy, and with considerable savings in the amount of time spent
modelling and analyzing.
Beskrivning
Ämne/nyckelord
Reinforced Concrete beam , CFRP, GFRP , Delamination , Crack Width , Bond-slip , Smeared Length