Hydrodemolition scarification removes the top surface of the concrete leaving a rough, irregular surface profile with coarse aggregate partially bonded in the existing surface. The aggregate then bonds and interlocks with the new overlay or repair material. The rough surface provides an excellent bond and shear transfer to ensure the success and durability of the new concrete overlay or repair material.
Hydrodemolition scarification maximizes the surface area for bonding. Mechanical methods such as rotomilling and jackhammers, shear the coarse aggregate leaving the surface relatively flat. In addition, rotomilling will cause micro-fractures in the substrate, thereby weakening the bond between the existing and the new concrete.
Scarification typically is specified to remove between ¼” (6 mm) and 1” (22 mm) of concrete.
When vacuum equipment is attached directly to the hydrodemolition robot, the wastewater and a portion of the debris is continuously vacuumed at the robot. This ensures that water will not leave the work area and potentially enter areas of live traffic. The process is referred to as Dry Hydrodemolition®.
Surfaces that have been previously rotomilled can be scarified to remove the microcracks (bruising) using our high-speed scarification process. This process removes ¼” (6 mm) to ½” (12 mm) of damaged concrete providing an excellent bonding surface. The method is 2 to 3 times faster than normal scarification equipment and also utilizes vacuum to recover the wastewater. It is an excellent option for bridge decks in good condition but need to add cover or remove rutting.