5 Common HydroDemolition Questions Answered

March 1, 2024

No matter your industry, you’ll likely get a set of questions that keep being asked repeatedly. Although HydroDemolition has been around for over 40 years, with common use for more than twenty years, we still find that many people are curious about the technique and technology behind HydroDemolition. From the obvious to the obscure, there’s a lot to know about HydroDemolition, and while our Lunch and Learn events are a great place to learn even more, there are plenty of questions that can be answered, and here are five of the most common questions about HydroDemolition and their answers. 

What is HydroDemolition?

Let’s be honest, the most commonly asked question about HydroDemolition would probably have to be: What is HydroDemolition? Thankfully, that’s a question we can answer well! HydroDemolition is a low-impact form of demolition, also known as hydro blasting or hydro milling. It is a commonly used technique for the removal of concrete and other materials using high-pressure or ultra-high-pressure water jets. Compared to traditional demolition techniques, HydroDemolition is an effective and precise method that cuts concrete without affecting the substructure, or the rebar, among other parts. To put it simply, HydroDemolition is an eco-friendly, more precise, safe, and rebar-preserving method of demolition that not only removes the selected concrete or material but can do so without releasing a lot of silica dust or using a lot of materials. HydroDemoliton uses the power of water, meaning you’re left with an intact rebar and a bonding surface that is clean and ready for sturdy, everlasting bonds. 


How Much Water Do You Need?

The answer to this will vary depending on the project at hand. The simple answer is: The amount of water you need is directly proportional to your high-pressure pump. If your pump needs 50 gallons per minute, then your water source needs to provide at least that, and probably a little more to account for overflow and extras. You’ll need to plan for additional volume if you use water to clean the surface after the HydroDemolition process.

But how many gallons per minute isn’t all people are looking for when they ask this. They also likely want to know other important things:

1. How much water will the site need to supply?

For urban projects such as projects in cities or towns, or those near a reliable water source, this might not be an issue. But for rural locations and those trucking in water, running out could spell disaster, making water logistics a top priority that needs to be worked out ahead of time. 

If  3,000 gallons every hour are needed to complete a project, and the water source is quite some miles away, there will be extra logistics to figure out and likely extra costs as well. 

To help combat this, Aggregate Technologies uses a better solution: a closed-loop system. This allows the wastewater to be treated on-site and reused. Aggregate Technologies uses a closed-loop system with two 21,000-gallon tanks. This allows for the collection of and recycling of water right on the job site, meaning that less water has to be supplied at one time since the water can pass through a loop to be used again. This saves time, frustration, and money. 

2. How much water has to be managed during HydroDemolition?

This will depend on the scope of the project, as with any specific dependent question. For example, A 50-gallon per minute pump will create 50 gallons of water per minute, at maximum RPM, regardless of the pressure. If the project ends up taking 40 hours, you’re looking at 120,000 gallons for the HydroDemolition process alone. How much water is used and managed depends on the factors of the job and the machinery used on the job. Aggregate Technologies always does what we can to reduce the amount of water needed and the amount of money spent. 

Aggregate Technologies uses a closed-loop system

How Much Pressure Is Used?

The amount of pressure used depends on what needs to be accomplished and how fast you need it done. Our HydroDemolition equipment operates between 15,000 and 50,000 PSI, which allows you to select the right pressure for the job at hand. This is true for both HydroDemolition and Hydromilling. But what’s the difference between the two?

For starters, HydroDemolition provides a more selective removal process and option. 

This means HydroDemolition removes the chosen concrete without damaging the surface around it. HydroDemolition also doesn’t cause microfractures, meaning that your results can last three times longer than traditional methods of demolition, like a jackhammer. The water jet travels over the surface at a constant speed and pressure, usually between 15,000 – 20,000 PSI. This method requires a high volume of water but maximizes productivity, efficiency, and preciseness. 

Hydromilling tends to use ultra-high pressures for controlled depth removal in concrete and other surfaces. The water jet involved travels over the surface at a constant speed and pressure, usually between 30,000 and 40,000 PSI, removing all concrete to a certain depth. This process uses a low volume of water but doesn’t allow you to be as selective. This is often the better option when you’re looking to remove large chunks of concrete at a time, with little need for any preciseness. Depending on the depth and what you need, your PSI may differ. 


How Do You Treat the Wastewater?

There are several ways to handle wastewater, from vacuum trucks to off-site treatments, to setting up your own filtration system or using OEM systems. Each method comes with unique associated costs and considerations. 

While hauling the water off-site for treatment is an option that some consider, the costs associated and the time commitment make it an impractical solution for most projects. Similarly, self-built systems require constant monitoring and more labor in general, which isn’t always cohesive with HydroDemolition sites. Arguably, the best solution for water treatment is an OEM-designed and tested system such as the system that Aggregate Technologies uses, which can be located on-site and even offers the ability to reuse almost half of the water used. 

However, not all OEM systems are created equal. Our water treatment system provides on-site, on-demand treatment with a compact footprint. Our unit can move up to 88 gallons per minute, or about 5,238 gallons per hour. Your swimming pool uses about double that and takes hours to fill via your standard garden hose. Now, imagine how fast our equipment is working when you consider that you’d be able to recycle your entire swimming pool of water in just around two hours. This is done through a series of treatment chambers that neutralize alkaline water to a proper pH and reduce suspended particles to just 20-40 ppm. The entire process can be monitored and controlled with the control system.

Most other OEM systems use mineral acid to treat water, which can be dangerous to handle, can be expensive, and can acidify the water if accidentally taken too far. Our water treatment system, on the other hand, uses carbon dioxide to neutralize water pH, avoiding all of these pitfalls. Additionally, the treatment unit is self-contained in a 20-foot shipping container. This container is easy to transport just about anywhere and can even be set up in less than four hours. Aggregate Technologies employs only the finest technology, setting every job for success. 

Why Choose HydroDemolition?

Perhaps the question of the hours is also the one that is somewhat the hardest to answer. Someone should choose HydroDemolition for its many benefits. There are countless benefits to HydroDemolition, and all of them are valid reasons to employ HydroDemolition services for almost any concrete removal or concrete cutting job. These benefits include but aren’t limited to:


Overall, it’s easy to see why someone should choose HydroDemolition, it’s smarter, efficient, precise, requires less materials, uses less crew, and gets your most difficult jobs completed on budget and on time. 

Type of Industries we utilize our concrete removal expertise in:

  • Civil Engineering
  • Heavy Industrial
  • Petrochemical
  • Railroad & Highway Bridges 
  • Ports, Piers, and Wharfs 
  • Offshore & Underwater
  • Locks & Dams
  • Paper & Steel Mills
  • Hospitals & Medical Facilities 
  • Commercial Buildings
  • Universities & Colleges 
  • Manufacturing Facilities 

There are many valid questions about HydroDemolition, from what it is to how much water it uses. HydroDemolition is efficient, it’s eco-friendly, and allows you to stay on budget while still receiving excellent results.

Interested to hear more about what HydroDemolition has to offer? Contact us today!

Contact us when you need a contractor with a record of safety and success for your concrete cutting and hydrodemolition needs.

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