Underwater Hydrodemolition

The highway was closed while inspectors surveyed the damage, finding least one column destroyed and another column severely damaged.

On the damaged 66-inch diameter column, five feet of the column above the water and 10 feet below needed to have the damaged concrete removed while preserving the rebar. Typically, divers below and crews above would manually chip away the damaged concrete. But Aggregate Technologies was called on to use their hydrodemolition process.

The ATI crew set up one of its Hydro-Bot systems, the Ergo System, on the damaged column. The operator adjusted the force of the high-pressure water cutter to remove only the damaged concrete, preserving the rebar and concrete that was still sound. By utilizing this unique service, Aggregate Technologies was able to do its part in speeding up the repairs to the bridge.

Hydrodemolition is not only faster than traditional methods, it does not cause additional damage to the concrete from vibrations or micro-fracturing, and with the remote-controlled process it is a much safer method. The process also leaves a rough and superior bondable surface for new concrete to adhere to.