What is Hydrodemolition?

That’s the question we get a lot! Hydrodemolition uses high-velocity water jets to remove deteriorated, delaminated, or contaminated concrete from reinforced concrete roads, bridges and other structures, like dams and parking garages.Yes, we remove concrete with water–at ultra high pressures (36,000 psi) and at speeds of 1,500 mph.

Those waterjets are very powerful–Rampart can remove up to 16 inches of concrete in a single pass–but the removal, the erosion of the concrete is targeted only where needed. So, hydrodemolition eliminates collateral damage to rebar and adjacent, structurally-sound concrete.

In addition, because the combination of hydrodemolition and our vacuum and debris removal services, leave the remaining concrete near pour-ready, hydrodemolition is both an effective and efficient way to (1) rapidly remove deteriorating concrete and (2) prepare the surface for the installation of new concrete.

Hydrodemolition is recommended by transportation departments of many states as well as construction engineers who have experienced its significant advantages over traditional impact methods, i.e., jackhammers and rotomillers. (Please see our completed projects map for a listing of locations.)

Types of Hydrodemolition

Rampart Hydro: High-Speed Scarification Rampart Hydro: Scarification Rampart Hydro: Partial-Depth-Removal Rampart Hydro: Full-Depth-Removal Rampart Hydro: Deep-Removal

At Rampart Hydro, our computer-controlled waterjets can remove the surface concrete to provide a light profile(scarification), additional removal either to the top of the rebar or ¾” below  the rebar  (partial-depth), or (full-depth), up to sixteen inches in one pass.

Based on the project’s specifications, we program our machines to remove the concrete to the specified  average depth; however, our jets can remove weak pockets beneath this depth, which further improves the  structural integrity and longevity of the repair.

Demolition is only half of our job, Rampart also uses various methods to capture, filter and reclaim the hydrodemolition wastewater and  reduce the pH to acceptable levels so that it can be discharged in accordance with environmental regurlations or, alternatively, reused for additional hydrodemolition.


There are many advantages to using hydrodemolition over traditional removal methods, including:

  • The rough, irregular surface profile provides an excellent mechanical bond for all types of repair materials:
  • The rough, irregular profile contains more surface area per square foot then any other type of concrete removal process;
  • Surface micro-fracturing (bruising) caused by mechanical removal methods are eliminated;
  • Exposed aggregates are not fractured, split or damaged;
  • Lower strength and deteriorated concrete (delamination) is selectively removed;
  • Vibration to the surrounding structure is eliminated;
  • Reinforced metal (rebar) is cleaned, eliminating the need for sandblasting;
  • Reinforcing and other embedded metal elements are undamaged.
  • Minimizes disruptions to users of occupied space by significantly reducing transmitted sound virbrations through the structure;
  • Increase speed of concrete removal, which can reduce construction time;
  • Minimizes dust and the potential for silicosis;
  • Robotic units reduce labor and minimize injuries compared to chipping hammers.

What is a Hydrodemolition System?

A hydrodemolition system consists of:

  1. High-pressure water pump(s);
  2. A robotic cutting head; and
  3. A support vehicle or trailer.

The trailer carries the (1) pump; (2) cutting equipment and vehicle; (3) spare parts and tools; and (4) fuel and water tanks.

Our pumps are powered by diesel and electric motors and each provide 16 gpm at 36,000 psi.  Two pumps power each hydrodemolition cutting tractor.  However in some cases three pumps may be used for high-strength concrete, deep removals, or faster production rates.

During hydrodemolition the pumps are set to operate at their designed pressure and volume.  The quality and depth of removal are controlled at the cutting tractor or other device.

All of our equipment meets California EPA emission standards.

What Controls Hydrodemolition Cutting Depth?

Simply stated, it is the length of time that the waterjet is directed at the concrete surface that determines the depth of removal, and contact time is controlled at the robotic cutter.

There are five parameters that determine the quality and depth of removal. 
They are:

  • Rotation speed of the nozzle
  • Angle of the nozzle to the surface
  • Height of the nozzle above the surface
  • Traverse speed
  • Advance distance

Rampart uses a variable speed-rotating nozzle, which can be adjusted from 0 to 1,800 rpm.  In addition, the nozzle can be angled between 5° and 30° from vertical. When rotating, the angled water jet creates a demolition cone.  By raising and lowering the nozzle the base of the cone can be increased and decreased in diameter.  The robotic tractor moves the rotating nozzle back and forth on a traverse beam perpendicular to the direction of the tractor and tractor advances following a preset number and time for the traverse.

However, more important than how is what it does? Hydrodemolition removes concrete in a safe, fast, predictable manner.

Rampart Hydro was one of the first hydrodemolition firms and is the largest–with the largest investment in vehicles, equipment, technology, and most importantly, people.

If you have a hydrodemolition project, and want it done right–with a maximum of up-time–contact us today.