Hydrodemolition (or hydro demolition), commonly referred to as hydro blasting, is a demolition technique that uses a high or ultra-pressure water jet along with abrasives or other materials mainly for the removal of concrete that has been deteriorated or for concrete repair and strengthening.
This technology, which was initially created in Europe in the 1980s, is now widely used in both Europe and North America for the removal of concrete and surface preparation. Hydrodemolition is a powerful technique for removing concrete that doesn’t harm the foundation or other components when compared to traditional demolition equipment. High-pressure water used in hydrodemolition widens pre-existing holes and micropores, breaking the concrete apart in a predictable rate.
Additionally, hydrodemolition leaves behind a roughed surface that is ideal for construction joints and for binding with new concrete. It also lowers the risk of breaking steel rebar during repair.
How Hydrodemolition Works
The process of hydrodemolition is carried out with the use of hydrodemolition equipment that employs either elevated or ultra-high pressure (UHP) pressurized water.
Three approaches are possible to accomplish this:
- Hydroscarification – When hydroscarification is utilized to remove the upper layer of concrete, extremely high-pressure water jets are employed typically ranges from 1⁄4 to 3⁄4 inches in depth.
- Partial depth extraction – Concrete with a depth of at least 3/4 inches can be selectively removed using partial depth removal.
- Complete removal – The entire degraded concrete must be removed fully during full-depth removal.
Benefits of Hydrodemolition
Microfractures are formed in the concrete when conventional demolition techniques like jack hammers are used. Reducing strength of the concrete significantly by these fractures and increasing the risk of delamination. Hydrodemolition removes concrete by using the impacts of eroding rather than compressive impact.
Enhanced Bonding Surface
Hydrodemolition technique easily isolates the two components because the aggregate in concrete has a greater compressive strength than with the cement that surrounds it. As a result, the aggregate is left undamaged while the cement to which it is connected is destroyed. This results in a cement base layer with exposed aggregates on the hydrodemolition surface ideal for construction joints in monolithic construction.
Keeping Rebar Intact
The high-pressure water jet used in hydrodemolition has no effect on the rebar because of the strong compression properties of steel. In reality, the steel rebar is cleaned during the hydrodemolition process, which helps successive repair.
Hydrodemolition virtually eliminates the risks in traditional concrete removal methods. This process is clean and doesn’t produce any silica dust, operators aren’t exposed to the risks of a demolition site, and they operate the robots from a distance, protecting them from those risks.
The techniques used in traditional approaches are frequently loud and dirty, greatly disrupting their surroundings. However, hydrodemolition produces almost no dust and significantly less noise than conventional demolition. To prevent it from contaminating natural water sources, the wastewater can be collected, treated, and recycled.
Applications of Hydrodemolition in Construction
Concrete placement is a challenging task. A minor mistake in one of the many different factors can ruin an entire batch. Robotic Hydrodemolition techniques have made it possible to fix them without structural damage.
Failure In Formwork
Hydrodemolition appears to be an impact-free method for removing concrete, offering a removal rate that is about 25% higher than jackhammers and some other handled tools. Unwanted Concrete layers due to incorrect placement removed by hydrodemolition.
Concrete Segregation and Other Batch Problems
Contractors can decide how the cuts are made by hydrodemolition robots and change the water jet’s pressure if loose, damaged concrete or unsound concrete due to Concrete Segregation needs to be removed to a certain depth. The robot carefully moves across the allocated area and removes material in accordance with the given parameters when the parameters are set. The hydrodemolition robot can also offer a cost-effective remedy for additional issues with concrete mix.
Existing Structures That Need Concrete Repairs
Hydrodemolition offers an efficient way to fix concrete weaknesses when something went wrong during the initial construction of a structure or as part of a remodeling or rehabilitation project. This lack of microfractures is primarily due to the impact-free method. Additionally, hydrodemolition creates a cleaner surface, eliminating the need for additional steps like sandblasting after jackhammering.
Non-compliant concrete mix results
When a failure is discovered, contractors can enter a building quickly using hydro-demolition, removing only the weaker components while maintaining the overall structural stability of the concrete and rebar that are still present. When the removal is complete, all that is left is the superior binding surface, which will deliver a durable repair. The high degree of controllability of hydrodemolition robots allows contractors to identify compressive strength failures on horizontally, vertically, or even overhead surfaces.
Possible Applications of Hydrodemolition in Civil Engineering and Construction:
Hydro-demolition is frequently utilized for strengthening and repairing bridges. Hydro-demolition is also widely used for preparing rough construction joint surfaces on precast deck panels and girders for in-situ concrete pours. Water jetting is a cost-effective alternative when concrete must be extracted or prepped for reapplication.
Preparation Of The Concrete’s Surface with Hydro demolition
The water jet merely removes the coating while cleaning coatings off of steel surfaces, leaving the steel unharmed and clean. Water jetting decreases the expense of cleanup and used abrasive disposal because it does not produce dust.
Concrete Section Cutting
The abrasive jet will probably be employed in the construction sector to cut concrete sections and steel beams. Compared to other tools, such plasma arcs, the water jet’s cutting rates for steel are lower.
Water-jet abrasive cutting of concrete expedites the realization of architectural designs and patterns varying from straightforward block letters to intricate and complicated designs.