X-Calibur is one of the latest product offerings from TAL and was specified to protect the concrete structure of the world’s second longest cable-stayed bridge against corrosion throughout its design life.
Stonecutters Bridge is a high level cable-stayed bridge which spans the Rambler Channel in Hong Kong, connecting Nam Wam Kok, Tsing Yi Island and Stonecutters Island. Hong Kong is well known for its hot summer weather, which is also humid and unstable. Temperatures usually exceed 30 degrees Celsius during the day, which, coupled with high humidity, can result in an extreme heat index. These climate conditions presented some additional challenges, but X-Calibur was able to overcome them.
“Hot and humid environments have a great effect on the durability of concrete. As a rule of thumb we say for every ten degree Celsius increase in temperature the possibility of corrosion induced damage to concrete is doubled. Add humidity in a marine environment then protection of the structure is of paramount importance,” says Brian Davies, CEO X-Calibur International.
In order to guard the bridge from corrosion, X-Shield EpoxySeal CR was supplied to shield the prestressed concrete cable anchorages from the effects of the environment. In addition, X-Shield FlexCoat was used in various areas of the structure. This provides corrosion protection to reinforced concrete from chloride and carbon dioxide.
As a result of the interesting challenges and extreme difficulty in constructing Stonecutters Bridge, the project was featured on two of the Discovery Channel’s Extreme Engineering series. “The main challenge was compliance with the strict project specifications as the engineer wanted to ensure that protection would be provided throughout the design life of the structure. X-Calibur had the products independently tested to prove compliance to all aspects of the specification,” he says.
The materials were applied by specialist painters who had been trained by X-Calibur. “Materials were mixed and applied strictly in accordance with method statements supplied by X-Calibur to ensure working time and recoat windows were not exceeded,” says Davies.
For more information contact Andrew Dekker, construction chemicals manager at TAL on 031 579 2263 or 082 650 4199 or visit www.tal.co.za and www.x-calibur.us.