The 2nd Yueyang Dongting Lake Bridge’s super toughness concrete (STC) pouring was finished on November 2, 2017. So far, the 65,000-sqm STC bridge deck construction has been completed. This is the first application of such technology in a km-scale extra-long-span steel truss beam suspension bridge.
The STC lightweight composite deck was developed by Prof. Shao Xudong’s high-performance bridge research team, including Prof. Huang Zhengyu and Dr. Cao Junhui, from HNU College of Civil Engineering. The STC bridge deck can dispense with overhauling for its whole service life.
Since this September, it has attracted four academicians, over 40 chief engineers and designers, and more than 200 peers for on-site investigation.
The STC bridge deck sections of the 2nd Dongting Lake Bridge join together.
The 2nd Dongting Lake Bridge, 2.39 km in length, is a major project between the Hangzhou-Ruili Expressway Linxiang section and Yueyang section. It connects Qili Mountain and Junshan Island, stretching across Dongting Lake. It will be China’s largest, and the world’s second largest span steel truss beam suspension bridge.
The 2nd Dongting Lake Bridge under construction
The original design of the bridge deck is composed of an orthotropic steel deck (OSD) and an asphalt pavement. However, there are two main challenges in such bridge deck around the world: steel bridge deck fatigue cracking problem, which always occurs within ten years; asphalt pavement damage problem, which requires frequent maintenance and overhauling, even in short period. These challenges cause high cost, and demands prompt solutions.
Shao’s team worked out a solution that can enhance the stiffness of the bridge deck on the premise of not increasing its weight. Based on two decades research on ultra-high performance concrete (UHPC) in HNU, they customized the STC with better performance in tensile strength and shrinkage property for steel bridge deck, and initiatively developed steel-STC lightweight composite deck structure. Research shows that, the STC can increase the partial stiffness by more than 30 times, while decreasing the deck stress by 50%.
The STC is currently widely used in 17 bridges in six provinces, including girder bridge, arch bridge, cable-stayed bridge, and suspension bridge. Over the past eight years, Shao’s team has been granted with 12 national patents for invention, compiled two local standards, published one monograph and more than 50 papers. Four papers were published on ASCE Journal of Bridge Engineering.