AN INNOVATIVE ACCELERATED BRIDGE CONSTRUCTION APPROACH INCORPORATING PRECAST PANELS, FIBRE-REINFORCED POLYMERS BARS AND ULTRA HIGH PERFORMANCE CONCRETE

摘要

The need for enlarging the extents and capacity of existing transportation structures has been growing rapidly worldwide during the past decade. Meantime, minimizing the impact on traffic and shortening the construction duration pose significant challenges to jurisdictions, engineers and contractors. This paper presents a project for widening an existing two-lane bridge over a major water stream within the Great Toronto Area (GTA). Two additional lanes are needed to improve the vehicular traffic flow of the road crossing the water stream. The subject bridge and its proposed widening are of a semi-integral abutment type. This type of bridges is characterized with high durability of both superstructure and substructure components. Two deck systems utilizing Steel Ⅰ-girders and Steel Box-girders were examined in order to achieve an optimum bridge design. Some of the various challenges were to maintain the existing bridge functional during construction and to keep the water stream beneath flowing free of any falling debris. Further, high durability measures were considered for the widening structure along with a reduction of the construction schedule within a reasonable budget. Therefore, the design/construction criterion focused an innovative accelerated construction approach in order to satisfy such challenging demands. Through such approach, a deck system of precast concrete panels reinforced with Glass Fibre-Reinforced Polymers (GFRP) bars and jointed, on site, with Ultra High Performance Concrete (UHPC) is proposed. The proposed construction methodology, complemented by such advanced construction materials, accommodates the technical and financial measures of the project from both short and long term aspects.