On the evening of April 17, 2020, after 13 consecutive hours of construction work, the concrete pouring into the first main chord pipe of the third Pingnan Bridge in Guangxi was completed successfully.

Pingnan Third Bridge is located in Pingnan, Guangxi. It is a special bridge that crosses the Xunjiang River on the Pingnan-North Interconnecting Line of Liyu Expressway. After completion, it will be the world's largest span arch bridge. The concrete pouring in the first pipe of the third Pingnan Bridge uses C70 self-compacting non-shrinkage concrete (hereinafter referred to as C70 concrete), which is vacuum-assisted four-stage continuous pumping for pipe pouring. An exhaust pipe, a sizing tube, etc., greatly improve the compactness of the concrete pouring in the pipe and reduce the risk of pipe blockage and bubble accumulation.

In order to ensure the optimal performance of C70 concrete, the research and test team of the Guangxi Luqiao Group project worked together to learn from Zheng Jielian, an academician of the Chinese Academy of Engineering, and Ding Qingjun, a professor at Wuhan University of Technology. It is difficult to successfully prepare C70 concrete with excellent working performance, controllable compensation shrinkage process, and mechanical properties that meet the design requirements. In order to ensure the high efficiency and quality of the infusion cycle, the project department intervened in advance to deploy and strictly control the materials. At present, the arrival rate of Pingnan Third Bridge materials and equipment has reached 100%, and the first quality control has been accurately controlled from the source.

It is reported that there are a total of 8 main arch ribs of the Pingnan Third Bridge, which are infused by vacuum-assisted four-stage continuous pumping process, which requires a total of 8 injections. The main string of this time is 650m long and 1.4m in diameter. It needs to be filled with about 1000 cubic meters of concrete. The continuous pouring time is about 13 hours. After the coagulation strength in the pipe reaches 80%, the next main string can be continued. Pipe concrete pouring construction, the concrete pouring construction of the full bridge pipe is expected to take about 30 days. Editor / Huang Lijun