 Hydrodemolition is very effective in removing concrete from around reinforcing or other embedded metal items without damaging them. If the concrete is deteriorated and/or delaminated, or if the chloride content exceeds the threshold level for the initiation of corrosion, then it will be necessary to remove the concrete from around all of the embedded metal items. Typically concrete is removed a minimum of ¾-inch from around the reinforcing.
Some of the advantages of hydrodemolition over mechanical removal methods (rotomillers, jackhammers, and chipping guns) are as follows: Hydrodemolition eliminates micro-fractures caused by mechanical removal methods. During hydrodemolition, the reinforcing steel and other embedded metal items are cleaned eliminating the need to sandblast. Hydrodemolition leaves exposed undamaged coarse aggregate in the surface profile. The Hydrodemolished surface profile is very rough providing the maximum amount of surface area for bonding.
All of these advantages help to provide an excellent bonding surface for the new overlay or repair material. Excellent bond strength is obtained when concrete is placed on a Surface Saturated Dry Hydrodemolished surface. Tensile bond strength tests have proven that the bond between repair material and a hydrodemolished surface is much stronger than the bond strength between a repair material and a mechanically prepared surface.  Partial depth removal may also be performed following the initial scarification of the deck surface. Following scarification, the deck is surveyed for delaminated or deteriorated areas. They are then marked for further removal, typically ¾ to 1.0 inch below the reinforcing steel.
| 
