Shamu International Pure Polyurea Challenges Hong Kong-Zhuhai-Macao Bridge

【www.polyurea.cn, 2013-01-06 News】Hong Kong-Zhuhai-Macao Bridge project, the largest oversea bridge in the world is another huge infrastructure construction following the Three Gorges Dam Project, the Qinghai-Tibet Railway, the South-to-North Water Diversion Project, the Beijing-Shanghai High-speed Railway. It connects the west side of Hong Kong to Macao and Zhuhai of Guangdong province. This ultra large sea-crossing passage combines bridges, islands and tunnels together. Among the project, the immersed tube tunnel construction is currently the most difficult tunnel engineering in the world. Especially the flexible connection and impermeable technology of immersed tube tunnels is recognized as a world-class challenge. How to make sure that pure polyurea technology can provide super protection to the large prestressed concrete members seams under humid conditions. That will be a big challenge for polyurea technology.

Qtech-412 pure polyurea produce of Qingdao Shamu International Trade Co. Ltd., and the fourth generation polyurea Hydraulic Spray Machine entered the immersed tube tunnel pouring jobsite of Hong Kong-Zhuhai-Macao Bridge in Guishan Island in LingDingYang. Polyurea’s protection in the joints of immersed tube tunnel will provide up to 120 years of service life. Therefore, Prof. Weibo Huang made a special trip to the construction jobsite for instruction and consulting.

The flexible connection and impermeable technology of immersed tube tunnels put forward high requirement in polyurea properties. After much investigation, finally the owner chooses Qtech-412 Bridge Ultra-Long Service Life Polyurea Material of Shamu International. The material is a new type anti-aging product which is independently developed by Shamu International for Bridges protection. It has been successfully applied to Qingdao Jiaozhou Bay Bridge in 2011 (details are available at: http://www.polyurea.cn/en/2011/2011-11-19/196.html). It has overall outstanding performance, such as fast curing, effective resistance to temperature and humidity changes, excellent mechanical properties, superior corrosion resistance, impermeability capability and excellent resistance to ultraviolent radiation aging of sunshine.

The fourth generation polyurea Hydraulic Spray Machine is known that PHX-40 proportioner stable pumping performance and super enduring resistance to voltage fluctuation ability and AP-2 spray gun lightweight and no backwash in close-distance spraying. Due to these advantages, the fourth generation polyurea Hydraulic Spray Machine conquered all the technical personnel of engineering.

PHX-40 Proportioner
Spraying on the top and bottom of immersed tube by AP-2 gun

Immersed Tube Preset Field	The First Joint Immersed Tube Tunnel
Surface Grinding Treatment	Brush Primer and Repairing Putty
Steel shear key isolation membrane process

Site sampling test result made by the authority showed that mechanical properties of Qtech-412 pure polyurea materials: tensile strength is 20.08MPa, elongation at break is 478.62%. The date has exceeded the provisions of Chinese National Standard GB23446 type Ⅱ indicators: Tensile strength is 16MPa, elongation at break is 450%. The hydraulic pull-off adhesion is 3.9MPa. The design institutes, owners and constructions are united in praise for all properties exceeding the design requirements of the technical indicators.

Completion Rendering	Adhesion Test
Qtech - 412 Pure Polyurea Material Sample test in Jobsite