HIGHEST GRADE GLASS FIBRE REINFORCEMENT: NEWEST DEVELOPMENTS AND APPLICATIONS IN BRIDGE PROJECTS

摘要

Glass fibre reinforcing bars are increasingly replacing epoxy coated and stainless steel rebars in bridge projects across Canada. This is due to their technical superiority (over epoxy coated bars) and to economic advantages compared to the installation of stainless steel reinforcement. As bending fibrous materials results in a substantial loss of their strength, it is difficult to produce glass fibre stirrups with material properties similar to those of straight bars. The installation of straight glass fibre bars with end heads as shear or punching shear reinforcement is, therefore, often a more economic solution. Most bar end heads available on the market to date were made of thermoplastic resins moulded onto the ends of the bars. A next generation bar end head has recently been developed, using ultra high performance polymeric concrete. The new heads are able to anchor far higher loads over much longer periods of time. The tensile splitting action of these heads is significantly less allowing for an installation close to the surface of concrete members. The first new bridge crossing the Grand River, linking Kitchener and Waterloo is currently being built as part of the Fairway Road Extension project. The Grand River bridge is 247 meters long and 25.85 m wide, providing ample space for sidewalks and bike paths in both directions of traffic. To extend the service life of the new bridge highest grade glass fibre reinforcement, including bars with headed ends made of polymeric concrete, is being installed in the abutments, abutment diaphragms and barrier walls. The glass fibre reinforcement is also used in the top layer of the sidewalks and the approach slabs of the four span bridge, which is to be completed in 2012. Results of lab tests on the new bar end heads, a full-scale crash test on a PL-3 barrier wall reinforced with these new headed glass fibre bars and technical details of the Grand River bridge are presented in the paper.