Bridge pylons

When complete in 2009 the six-lane, CNY 6.45 billion (US$ 726 million) Sutong Bridge will link Nantong and Changshu.

Main contractor China’s Second Navigation Engineering Bureau started on site in June 2003 and has just topped out the two 300 m high pylons, which stand on concrete foundations anchored in bedrock 122 m below the riverbed. Pontoons act as working platforms and house the mixers and stationary concrete pumps, including a high-pressure Putzmeister’s BSA 14000 HP-D. It is delivering 30 m³/hour of high-strength concrete (C80) through a 125 mm pump line. “The aggregate mix was one of the hardest we’d seen,” said a Putzmeister spokesman. “It consisted of open-pored, ground slag, while a sharp grit is used for a grain size of 4 mm. The largest aggregates, 5 to 25 mm, are made from hard-wearing granite, besides which there were also some extremely difficult additives to contend with.”