The ultra-high-performance concrete bridge deck paving of the Dongting Lake Super Bridge of Menghua Railway. It is reported that the concrete's flexural strength is 3 times that of ordinary C50 concrete, shrinkage is reduced by 50%, and is still intact after 700 freeze-thaw cycles. It is called "never cracking" concrete.
“Our independently developed low-shrinkage ultra-high-performance concrete materials and 'steel-ultra-high-performance concrete paving technology' can completely solve the worldwide problem of fatigue cracking of steel structures.” Wang Tianliang, deputy chief engineer of China Railway Bridge Bureau, introduced For the Dongting Lake Super Large Bridge on the China Railway and the Jingliang Railway on the main bridge of the Jingzhou Gongtie Yangtze River Bridge, this composite bridge deck is adopted as the deck structural layer and waterproof pavement.
It is understood that China's self-developed, low-shrinkage, ultra-high-performance concrete with world-leading level is more conducive to engineering due to its ultra-high mechanical performance, superior durability, and excellent volume stability and superior work performance. Diversification of structure, light weight, thin wall, construction, maintenance, maintenance more convenient, can greatly reduce the maintenance cost of the entire project life cycle.
“We first performed shot blasting on the steel bridge deck, welded the shear bolts, then carried out anti-corrosion coating, then installed steel mesh, and finally poured 5 cm thick ultra-high-performance concrete.” Dongting Lake Super Bridge Deck Shop The person in charge of the project, Chen Luyi, director of the New Material Research Institute of the China Railway Bridge Science Research Institute, briefed the reporter.
“The steel-ultra-high-performance concrete composite bridge deck was first applied in 2016 in Taile City, and it has been used for many times in the repair and reinforcement of various types of bridges.” Tian Qixian, General Manager of China Railway Bridge Research Institute, said, “This time At the same time, we have paved the two bridges together, with a total paving area of 24,000 square meters.It is meaningful both for the first time to apply steel-ultra-high performance concrete composite bridge decks in domestic railway bridge decks or for large paved areas. Extraordinary, it will promote the wide application of ultra-high performance concrete and new composite deck structures to further improve the overall health and safety of the bridge structure."
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The Menghua Railway Dongting Lake Bridge is one of the key control projects for the coal passageway between Mengxi and Central China. It spans the mouth of the Dongting Lake of the Xiangjiang River and is the world's first three-tower cable-stayed bridge. The total length of the bridge is 10444.659 meters, the length of the main bridge is 1290.24 meters, and the width of the main raft is 14 meters. It can bear a load of 10,000 tons, and it can meet the operating speed of 120 kilometers for heavy-duty trains. Due to its novel structural design, difficult construction techniques, and numerous technological innovations, the bridge has created five “firsts” among similar bridges at home and abroad:
First, the world's largest span of the Three Towers cable-stayed bridge;
Second, the world is the first time in the form of a steel box steel girder combined with a main girder on a cable-stayed bridge;
Thirdly, the first time in the world, the first construction of the Helong steel box girder on the cable-stayed bridge was adopted, and then the construction plan was installed;
The fourth is the first time in China that the middle tower plus stiffeners are used on the railway bridge.
The fifth is the use of steel-ultra-high-performance concrete new composite deck systems on the railway bridge for the first time in the world.