02 May 2008
Changshan River is a busy shipping route, so the bridge is being removed in small sections, with an emphasis on care and precision. The main contractor, a state-owned company called ‘The Second Company of The Transportation Construction Group of Zhejiang Province’, is using three Hilti DS-TS 32 saw heads with the appropriate blades, powered by D-LP 32 hydraulic units, along with DS-WS 15 diamond wire saw as well as the lighter, easily-handled DS-WS 10 units for the horizontal cuts.
Other equipment includes a DD 130 diamond coring system to drill holes in the concrete that are needed to thread the diamond wires through.
Support is provided by Charlie Ren and Gusty Taymans, diamond systems specialists with Hilti China. Mr Taymans told D&Ri, “The sections are cut vertically from the edge of the carriageway are 4 m x 4 m (13’ x 13) in size, and those from the middle of the carriageway measure 2.5 x 4 meters (8’ x 13). They have a thickness of 350 mm (13) on average.” He explained that wire saws even cut through concrete as thick as 450 mm (18) and also slice through rebar and tensioning cables.
John Ding is responsible for infrastructure projects at Hilti China, where he oversees construction of streets, railway lines, sea and airports. He estimates that China has 4000 bridges each year that require renovation, enlarging or strengthening.