Externally-bonded
fiber reinforced polymer (FRP) composites are a maturing technology for the
repair and retrofit of
existing concrete structures. Current guidelines for the
design of FRP
strengthening measures do not explicitly
consider the
uncertainties present in the FRP properties. Load and
Resistance Factor Design
(LRFD) provides an ideal framework for these considerations and is compatible
with existing trends in civil engineering design codes. A recent project has
studied the application of LRFD to FRP strengthening schemes. A widely
applicable design framework has been proposed using a composite specific
resistance factor to consider material variability, and a set of application
factors to consider specifics of field manufacture. This paper describes the
calibration of resistance factors for the example case of flexural
strengthening of T-beam reinforced concrete bridge girders. The calibration
considers FRP degradation based on existing durability models and continued
degradation of the original structure is modeled by considering general
corrosion of the reinforcing steel. Representative girders were selected from a
sample of California bridge plans. The reliability was evaluated using
simulation and first-order reliability methods.
More abstracts about the LOAD AND RESISTANCE FACTOR DESIGN FOR FRP STRENGTHENING OF CONCRETE STRUCTURES