On March 7, the south main tower legs of the South Navigational Channel Bridge of the newly-constructed Hangzhou Bay Sea-Crossing Bridge on the Tong-Ning-Yong High-Speed Railway were successfully closed, marking the official transition to the construction phase of the upper tower columns, and laying a solid foundation for the subsequent capping of the main tower and the timely completion of the entire bridge.

The newly-constructed Hangzhou Bay Sea-Crossing Bridge on the Tong-Ning-Yong High-Speed Railway has a total length of 29.2 km. It is currently the world's longest sea-crossing high-speed railway bridge project constructed with the highest standards. The South Navigational Channel Bridge is a double-tower cable-stayed bridge with a main span of 364 m, serving as a critical control project for the entire line. The south main tower, which recently completed closure, is of reinforced concrete structure with a total height of 157.5 m. The middle and lower tower sections stand at 105.5 m tall and feature a concrete double-leg structure; the upper tower section, which anchors cables, is 52 m high.

During the construction of the 105.5 m-high main tower, vertical concrete pumping presented a core technical challenge. The HLC-IX retarding polycarboxylate-based superplasticizer developed by Nanjing R&D Hi-Tech Co., Ltd. (hereinafter referred to as “the Company”), affiliated to NHRI, was used in the Project. The Company collaborated closely with the Project Department of CCCC Second Harbor Engineering Co., Ltd. Taking the environmental characteristics of the Hangzhou Bay area, such as frequent monsoons, strong tides, and salt spray, into account, the Company participated in optimizing concrete mix design. While ensuring strength and durability, and controlling heat of hydration and setting time, the Company significantly improved concrete workability, mitigated the risk of pipeline blockages, and ensured the continuous and stable conveyance of concrete for the ultra-high tower columns.

The application of this superplasticizer fully demonstrates the Company's professional technical expertise in the R&D and application of concrete admixtures, providing high-quality and reliable materials for the construction of ultra-high tower columns. The Company dispatched a professional technical team to provide on-site services, tracking the whole construction process and adjusting concrete performance in real time. From pile foundation construction to main tower erection, the Company adhered to a customer-centric approach, safeguarding the project quality throughout the process and contributing to the efficient and steady progress of the Hangzhou Bay Sea-Crossing High-Speed Railway Bridge.