Nansha Bridge, a transportation artery newly built in the heart of the Greater Bay Area, was open to traffic this Tuesday. Scientists and engineers of SCUT contributed greatly to solving the scientific puzzle of laying down large areas of road surface on the bridge.
The 12.89-kilometer bridge was a two-way, eight-lane passageway connecting Guangzhou and Dongguan across the Pearl River. With designed driving speed of 100 km/h, it is expected to considerably relieve the road congestion on both sides of the river.
The Nizhou Waterway Bridge is one of the two main bodies of this cross-river traffic system. Its main span reaches 1,688 meters, which makes it the world's largest suspension bridge that uses steel box girders.
Laying down road surface on such a major project posed difficult challenges to its designers, who needed to deal with the particular climate of high humidity and temperature in the Pearl River Estuary, and to make sure the pavement has enough durability and anti-slipping performance that are able to sustain extremely heavy traffic loads.
Zhang Xiaoning, a professor at the Institute of Road Engineering of SCUT, was assigned to lead the research on finding a technique of pavement and conducting quality control. His team was looking at as large as 130,000 square meters of road surface on a highway over water.
After thorough studies, researchers at the institute decided to use hot mix epoxy asphalt as the surface material. In addition, to avoid the high fault and repair rate and poor performance in anti-slipping that had been reported in other similar projects, they used full asphalt content (FAC) concrete to strengthen the pavement.
This was the first time, in China or in other countries, to use hot mix epoxy asphalt plus FAC to lay down large-scale pavement on steel decks. The team spent more than a year to compare and conduct tests on tens of different types of materials, and finally found a solution that was able to meet a series of designed goals, including strong durability, stabilities in high-temperature, low temperature and water environments, as well as adequate performances in watertight sealing and anti-slipping.
Except for Zhang Xiaoning, several key engineers in the project also come from SCUT, including Xu Wei, Ma Lin, and Zhang Shunxian, who are all PhD graduates trained by Zhang Xiaoning, and they together formed an extraordinary teacher-student team.
Zhang Xiaoning is known for his academic reputation in road surface engineering, especially in dealing with road pavement on steel box girder bridges. His team also contributed to the building of the Hong Kong-Zhuhai-Macao Bridge, which was open to traffic last October and became the longest sea-crossing fixed link on earth.
Source from the School of Civil Engineering and Transportation
Translated by Xu Peimu
Edited by Xu Peimu and Wang Manjie
From the SCUT News Network