GCP ‘protects’ new highway between HK and Shenzhen

The Liantang/Heung Yuen Wai Boundary Control Point, also known as the Liantang Highway, is designed to provide a direct transport link and expedite travel between the northeast New Territories in Hong Kong and Shenzhen East on Mainland China. The new highway is also expected to alleviate traffic and congestion at the two existing boundary control points at Man Kam To and Sha Tau Kok, on the eastern side of the New Territories.

Covering 57 acres, the Liantang Highway project includes construction of an 11 km two-lane concrete road bridge linking the new highway with Fanling Highway; border patrol buildings and associated facilities; improving about 4.5 km of Shenzhen River between Ping Yuen River and Pak Fu Shan and re-provisioning Chuk Yuen Village.

Key challenges of the project involved finding a way to effectively prevent water ingress on the concrete road bridge deck, reduce the risk of waterborne contaminants and prevent the onset of early corrosion. The contractor needed a waterproofing system that was compatible with the structure’s design-life requirement; engineered to provide sufficient bond and movement with the substrate and asphalt paving; tough and suitable for fast-tracking application, particularly during Hong Kong’s wet and humid seasons. The bridge deck waterproofing solution also needed to have a track record of meeting strict construction and technical compliance, plus stringent lab testing.

The main contractor, Chun Wo Construction Holdings Company Ltd, finally selected the Eliminator bridge deck waterproofing system from GCP Applied Technologies to protect the concrete road bridge section of Liantang Highway. The Eliminator waterproofing membrane’s formulation, which is based on Esselac technology, allows for application in high humidity while providing rapid full cure and early trafficability.

The cold-spray-applied Eliminator system ensured ample tensile and shear bond between the asphalt paving and membrane. It also provided Chun Wo Construction with significant speed and efficiency advantage over traditional hot melt-type bond coats, without compromising quality and performance. Plus, the use of airless pumps made it fast and easy to apply and maintain.

Advance Specialist Treatment Engineering Ltd was tasked to apply the Eliminator system on the project. The company said it could apply the system on the concrete substrate seven days after the pouring, on an area of about 1,000 sq m a day in good weather condition and with relative humidity up to 98%.

On the Liantang Highway project, two coats of Eliminator waterproofing membrane were applied. The first coat was a distinctive yellow, followed by a second coat that is light grey, enabling superior quality control over one-coat membranes.

The Eliminator system forms a tough, flexible and seamless membrane with no vulnerable joints, allowing it to perform throughout the design life of a structure while simultaneously reducing maintenance costs. Its installation causes minimal disruption, and it is capable of supporting traffic just an hour after application. The system allows for wet film thickness gauge checks to ensure the specified film thickness is achieved across the area before curing.