Subpar surface preparation can have a negative impact on the integrity of the structure and lead to premature failure, increasing repair intervals and overall costs. The International Concrete Research Institute (ICRI) technical guideline 310.2R-2013 pertaining to selecting and specifying concrete surface preparation identifies hydrodemolition, sometimes referred to as water blasting or water jetting, as one of few methods capable of achieving CSP 3 through 10. This versatility allows hydrodemolition contractors to efficiently achieve CPS 3, suitable for some thin film and high build film coatings, all the way up to CPS 10, which is necessary for concrete overlays and repair materials greater than .25 inches (6 millimeters).
“Proper surface preparation is necessary for long-lasting concrete restoration. Hydrodemolition not only provides a superior bonding surface, but it’s one of the only high-productivity methods that doesn’t cause microfractures,” says Roger Simonsson, managing director, Aquajet, a manufacturer of hydrodemolition robots and attachments for improved surface preparation.
“We developed our Rotolance attachments to maximize these benefits; they bring the power of hydrodemolition to surface preparation applications, allowing operators to achieve CPS 3 through 10 with the same machines for increased utilization and versatility, leading to enhanced overall return on investment,” he adds.
Aquajet’s Rotolance attachments clean, remove and roughen concrete, leaving a better bonding surface that meets international guidelines for the majority of concrete surface profiles (CSP). Rotolance attachments pair with the company’s Aqua Cutter 410 and 710 series robots, the new Aqua Cutter 750V, Ergo System and Aqua Spine, providing increased productivity and enhanced worker safety for surface preparation applications over manual methods such as sandblasting, hand lancing or pneumatic breaking.
Rotolance attachments use a rotating spray bar with multiple nozzles. With hydraulic operation and rotation speeds up to 1000 RPM, the spray bar adjusts to meet surface preparation requirements for a number of profiles. Combined with the adjustable traverse speed of Aquajet’s hydrodemolition robots, Rotolance attachments provide precise results in horizontal, vertical and overhead applications. Depending on pump flow, pressure and desired profile, Rotolance attachments can achieve production rates in excess of 500 square feet (46.5 square meters) per hour.
Contractors with a lightweight Ergo System can choose from two Rotolance attachments — the Rotolance 130 and Rotolance 130S — for maintenance and removal applications at bridges, harbors, water treatment facilities, reservoirs and tanks. The attachments offer new versatility for the Ergo System and are compatible with the Ergo Climber and Ergo Spine to provide access in confined or hard-to-reach places. The Rotolance 130S is also equipped with a suspension system, allowing it to follow uneven or curved surfaces such as ship hulls and storage tanks.
The Rotolance 1000 and Rotolance 2500 pair with Aquajet’s Aqua Cutter robots and cover a surface diameter as wide as 14 inches (360 mm). A vacuum port allows contractors to connect a vacuum system for water recovery, ensuring safe, environmentally friendly operation. Additionally, both Rotolance attachments can replace the regular cutting heads on the Aqua Spine, allowing operators to remove concrete that would be difficult or impossible to reach with a robot alone. The Rotolance 1000 is rated for a maximum pressure of 1000 bar or 14,500 PSI, while the Rotolance 2500 is rated for 2500 bar or 36,250 PSI.
“Doing more with less equipment is important on the jobsite and on the budget. We’re always looking for attachments and options to make our hydrodemolition robots more versatile, so customers can increase service offerings and grow their operations without having to invest in multiple machines. With a Rotolance attachment, they can achieve the widest range of surface profiles with minimal equipment,” says Simonsson.