| This thesis presents the results and analysis of an experimental study to investigate the shrinkage and cracking behaviour of GFRP- and steel-reinforced concrete barriers subjected to real environmental and load conditions. Through a collaboration project between the Ministry of Transportation of Quebec (MTQ) and the University of Sherbrooke, the field monitoring of GFRP- and steel-reinforced concrete barriers type MTQ 202ME was conducted. The barriers are constructed on a 6-lane concrete bridge using high-performance concrete with a compressive strength of 50 MPa after 28 days. The barrier under consideration was incorporated in a new Highway 410 Overpass Bridge, located in Sherbrooke, Quebec, which was cast in June 2010. The barrier separate the six-lane bridge into three lanes in each direction. The field monitoring included two sections of 23 m-long and 24 m-long. The first section (24 m-long) was reinforced with GFRP bars and the second one (23 m-long) was reinforced with galvanized steel bars. The main objective of this investigation was to evaluate the restrained shrinkage cracking behaviour of median barriers by monitoring the crack initiation and propagation as well as the strain evolution in both GFRP- and steel-reinforced sections. Besides, the effect of early age shrinkage and cracking of the high-performance concrete was captured thought the monitoring. The GFRP bars were instrumented with fiber-optic sensors (FOS) at different locations along the barrier length while the steel bars were instrumented with vibrating wire strain gauges (VWSG). Thermometers (TH-T) were also used for temperature measurements. In addition to the FOS and the vibrating wire strain gauges, electrical resistance strain gauges (ESG) were also used for additional measurements. The vibrating wire sensors and thermometers were connected to two multiplexers and a Datalogger to capture their readings while the FOS sensors were connected to a 16-channel DMI unit to capture and store their readings. The readings of the ESG, however, were captured using the P-3500 readout unit. Finally, a finite element model of the barrier was designed and compared with experimental values obtained. This research is to assess the optimal amount of longitudinal reinforcement necessary to control the crack width of FRP reinforced concrete at the same level as the steel reinforced concrete. In the near future, it would be possible to believe that through this research project several retaining structures reinforced with FRP could be built.;Keywords: Concrete barrier, GFRP, durability, corrosion, shrinkage, cracking, modelling.. |
