臺南都會區北外環道路-超高性能混凝土(UHPC)伸縮縫之國內首例應用

Ultra-High Performance Concrete (UHPC) is a fiber-reinforced cementitious material, which is known for its superior mechanical properties, durability, and workability. Due to the high particle-packing density and addition of fibers, UHPC has the ability to inhibit the crack formation and possesses high tensile strength and ductility. Given this, the common weakness of conventional concrete and high-strength cement mortar, including brittle behavior and spalling, is greatly alleviated by using UHPC. In addition, UHPC is more durable than conventional concrete and high-performance concrete owing to the low water-to-binder ratio, high particle-packing density, and crack-resistant ability. As a result, the durability measures, including porosity, permeability, chloride ion diffusivity, and abrasion resistance, are substantially lower than those of conventional concrete materials, which can protect structures from harmful substances. The construction of Tainan Urban Zone Northern Outer Ring Road links the core urban area of Tainan and Southern Taiwan Science Park, which will effectively mitigate the traffic congestion between nearby roads and No. 1 Provincial Road. The existing routes such as No. 39 Provincial Road and No. 86 Provincial Road will be connected by the North Outer Ring Road. As a result, the convenient outer ring expressway system in the core area of Tainan metropolitan will be realized. The route of this project runs along the embankment of the Yanshui River, and the mainline consists of the viaduct. After the completion of this project, it will become an essential path in the Tainan metropolitan. In the third phase of the project, the construction and design units applied UHPC for the expansion joints in several bridge sections. It aimed to compare with other expansion joints using conventional high-strength non-shrinkage concrete to understand the performance of UHPC. In addition to reporting the expected effectiveness of UHPC in the new expansion joints, the paper also introduces the construction processes of the UHPC expansion joints. For the potential follow-up monitoring, it is expected to use non-destructive testing methods to continuously examine the mechanics and durability of the UHPC expansion joints and compare the results with other expansion joints using conventional high-strength non-shrinkage cement mortar.