Waterjet cutting of concrete: water wears away stones

Concrete waterjet cutting is a creative and effective technique that has transformed the building and demolition sectors. This method carefully slices through hard materials like concrete using a high-pressure stream of water that is frequently combined with an abrasive substance. With many advantages over conventional cutting techniques in terms of precision, security, and environmental effect, it’s a potent substitute.

The ability of waterjet cutting to make precise, clean cuts without producing heat or creating microfractures in the concrete is one of its main advantages. The material’s integrity is guaranteed by this cold-cutting method, which makes it perfect for projects requiring extreme precision and little harm to neighboring structures. It’s also a safer choice for the environment and the workforce because there isn’t any dust or hazardous gases present.

Extremely adaptable, waterjet cutting can be used for a variety of tasks, from straightforward cuts to complex designs. This method offers unmatched flexibility whether you’re working on custom concrete designs, demolitions, or renovations. Professionals seeking to maximize output while reducing waste and downtime turn to it because of its accuracy and efficiency.

With the construction industry always changing, waterjet cutting is one innovative solution that can keep up with the demands of contemporary projects. Its environmental friendliness, safety, and precision combine to make it an invaluable tool for any concrete cutting task. Adopting this technology can result in more sustainable construction methods and improved project outcomes.

Stages of a long and complex path

It is a well-known fact that a stone can be effectively sharpened with a drop of water. The crucial point was that the process might take thousands or even millions of years to complete. Accelerating the process was the only thing left to do, but for some reason, it took a long time to be successful.

In the final stages of the Third Reich, German military engineers attempted to theoretically justify the hydraulic cutting processes for the first time. The plan was to use common water, which is highly accessible and has good energy transmission capabilities, to break the molecular bonds that hold steel together.

When it came to practical implementation, the state of technology at the time made it impossible to create a precision pump that could genuinely produce the working jet’s parameters.

• This is, for a moment, 4000 atmospheres of pressure and 1200 meters per second of flow speed. And today it looks impressive, doesn"t it? In general, the case died down and was raised from the dust of the archives by Soviet trophy teams, who were actively hunting for technological secrets of Nazi Germany at the end of the war. After some refinement, Soviet scientists in 1947 announced the discovery of an innovative method of cutting materials using water. However, given the lack of practical developments, the implementation of the project in an existing installation also did not take place.
• The Americans were given the floor. And they said it. The first working sample was used for cutting large diameter logs. The installation worked, but was unstable.
• Then things got a little more fun, and the cutting ability of water began to be used for cutting composites and heat-resistant materials when thrown into space.
• The next step was the creation of waterjet cutting technology, when a small amount of abrasive was added to water, which accelerated the speed of the process tens of times. A year after the creation of the operating universal installation, already in 1980, the technology entered the market and began to be widely used for cutting metal, concrete and glass.

Glass, for example, is one of the delicate and fragile materials that waterjet cutting has long been used to successfully cut.

In 1974, a specialized installation designed for concrete waterjet cutting was successfully tested when it became necessary to make a technological hole in the computer center building’s supporting reinforced concrete structure because the structure’s specifications prohibited high vibration loads from being used.

The design and its heart

One traditional application of the technology, concrete waterjet cutting, includes:

• High-pressure pump consisting of precision plunger pairs that compress water to high values ​​and give it a stable dynamic impulse. It should be noted that there are two types of plunger pump: direct action and reduced. Unlike a direct-acting pump, a reduced one has a main channel of a smaller cross-section than the working chamber, which gives an increase in pressure and flow rate by 25% higher compared to direct-flow pumps.

The foundation of any concrete waterjet cutting system, no matter how basic or inexpensive, is a high-pressure plunger pump.

• Mixer line, consisting of high-strength tubes with a diameter of up to 10 mm and a length of up to 100 mm, in which the abrasive is mixed with water and accelerated to operating speeds. In this case, the ratio of the outer diameter to the inner one can fluctuate within certain limits, depending on the grain size modulus of the abrasive used. The mixing pipe is a consumable item and its service life ranges from several hours to two hundred.
• Supply fittings and backbone system of communicators.
• Abrasive containers.
• Security group elements.
• Working nozzles of different diameters, directly dependent on the type of work performed.

A plunger pump’s basic operating diagram is similar to that of a pump found in home appliances meant for high-pressure washing.

Application of waterjet cutting and its features

A concrete massif with a thickness of roughly 1000 mm can be cut through by powerful contemporary equipment, and this method has a number of benefits over traditional methods.

1. Absence of harmful dust, which is released en masse during mechanical cutting, and the fight against which, with traditional methods of exposure to concrete, requires the use of additional dust suppression measures, such as irrigation.
2. Much lower noise levels.
3. Absence of vibrations and obvious dynamic oscillations, which is very important when carrying out delicate work in rooms with special conditions.
4. Possibility of carrying out a curvilinear cut, a cut at a reverse acute angle, a radius cut with a small step, which in most traditional cutting methods is difficult to implement or is associated with additional operations, costly both in terms of tool consumption and operator labor costs.
5. The energy carrier is water, and in most cases — fractionated enriched quartz sand, which is less expensive compared to the use of circles, crowns, cutters made of hard alloy, composite and working surfaces with diamond spraying.
6. Water and abrasive are environmentally friendly materials that do not require special measures for their disposal after the operation is completed.
7. The operator of the unit works in more comfortable conditions compared to traditional technologies.
8. Waterjet cutting units can be performed both in a mobile and stationary version, are easily digitized in a three-dimensional coordinate system and can be used as machines for the manufacture of complex volumetric concrete products for various purposes.
9. Can be used underwater, in work related to the elimination of emergency situations on utility lines.
10. Give a clean, well-matched cut.

A numerical control system installed in a stationary waterjet cutting unit is a sophisticated and highly efficient system.

Concrete is broken with a wedge

Using a hydrowedge to break up concrete is a technology that differs slightly from waterjet cutting concrete. Furthermore, there are a lot of differences between the two technologies. Comparable to the distinction between a surgeon’s scalpel and a butcher’s axe. Furthermore, a concrete hydrowedge functions exactly like an axe.

A mass of cast concrete covered in a set of hydrowedges works slowly but surely, quietly, and dust-free.

What’s essential. When breaking large amounts of monolithic concrete with low vibration loads and to reduce the chance of secondary fragments flying away from the disassembled structure, diamond crowns are used to drill holes in the concrete mass that have a diameter of about 160–180 mm.

After inserting the hydrowedge’s working cylinders into the holes that have been prepared and applying pressure, the massif splits into cakes, or discrete pieces that can be either transported or cut on-site with a small hand tool.

How it works

The technology is predicated on the mass of concrete’s poor tensile strength. Although concrete can withstand high static loads with ease, it is frequently severely affected by acute, local, dynamic stresses that cause the massif to deform and shatter into pieces of varying sizes.

The hydrowedge is essentially a hydraulic cylinder with a short arm and a high-speed rod that moves the working mechanism, which takes the shape of an established wedge made of high-strength alloy steel.

Such a system typically consists of:

• Hydraulic cylinder with a working element.
• High-pressure oil stations.
• Working lines made in the form of high-pressure hoses.
• Communicator systems made either in the form of quick-release couplings or according to the classic nipple-nut system.
• Control and safety systems.

The oil station functions as a hydraulic power unit, producing the necessary energy that is sent to the working element via a hydraulic line to accomplish the required work.

It should be mentioned that the technology being described is very portable, easy to maintain, and mobile. In general, hydrowedge destructors are dependable and long-lasting when used properly.

Crucial! Another distinction between the technology of hydrowedge and waterjet cutting is that a unique hydraulic oil is used as the energy carrier instead of water mixed with abrasive solid particles. Furthermore, the steel wedge that serves as the working element is not solely a carrier; the oil merely transmits the energy that is received.

An excellent tool for breaking up concrete is a hydrowedge; in certain situations, its mobility, weight, and dimensions make it nearly indispensable. But what should happen when the reinforced concrete massif becomes overly dense with reinforcement, akin to a watermelon overflowing with seeds? Hydraulic scissors will save the day in this situation.

Concrete waterjet cutting is a cutting-edge method that uses high-pressure water to precisely cut through concrete surfaces. With a concentrated water jet combined with abrasive materials, this method "wears away stones" and has several advantages over conventional cutting techniques. For a variety of building and demolition tasks, it is the perfect solution because it is quicker, more precise, and produces less dust and debris.

Scissors, but not tailor"s

Typically, when people think of scissors, they automatically think of cutting materials like leather, paper, cloth, and other less sturdy materials. For reinforced concrete, how about the hydraulic shears option? There are such, I assure you.

With their raw power and aggressive appearance, hydraulic shears strongly resemble a tyrannosaurus, a type of extinct lizard.

Crusher and cruncher: brothers, but not twins

Among the many tools that come with excavators—which are typically tracked—are hydraulic shears. The working mechanism consists of two high-alloy tool steel cheeks that move in accordance with a predetermined algorithm thanks to hydraulic cylinder rods driven by a typical high-pressure hydraulic system.

Reputable manufacturers’ hydraulic shears are equipped with a rotary head that permits you to turn the working element on its axis.

An incredibly helpful device that enables the scissors to both turn and rotate around the axis is a hydraulic rotator.

Modern models of hydraulic shears, which have a quick-release mechanism, are made and designed so that the excavator operator can install and remove them alone. He connects only the hydraulic system’s connectors with his hands.

Excavator operators, even the low-skilled ones who make up the majority of the domestic labor market, can easily master the operator’s manual because it repeats the working algorithms of the boom and bucket movement of the machine during the main and most common works.

It is imperative to provide protection for the excavator cabin equipped with hydraulic shears to shield the operator from broken concrete fragments and to preserve the glazing.

The primary reason for the high cost of these systems is that only American, European, and Japanese manufacturers produce efficient mechanisms. Chinese and domestic developments are essentially cheap replicas of well-earned brands; they are incredibly ineffective and fleeting.

A crusher is used to roughly destroy reinforced concrete structures because it has larger, more powerful teeth and more capture cavities in its working element.

The Swedes have unveiled an excavator with a lifting cabin and an extra-long boom that is intended especially for demolishing big buildings.

Broken concrete pieces are crushed using a cruncher. Concrete fragments can be broken up with its jaws to create a mass that can be used for backfilling, temporary road construction, cushion organization, and other purposes.

This method yields secondary crushed stone with a fraction of 40–70 mm, which is ideal for wedging crushed stone cushions.

Watching the video in this article will teach you more about the fundamentals of concrete waterjet cutting, as well as concrete structure disassembly using hydraulic shears and a hydrowedge.

Advantages of Waterjet Cutting	Disadvantages of Waterjet Cutting
Precise cuts without damaging surrounding material	High initial equipment cost
No heat generated, preserving the integrity of concrete	Slower cutting speed compared to other methods
Can cut through thick concrete	Requires a large amount of water
Environmentally friendly, as it does not produce dust	Potential for water management issues

Concrete waterjet cutting has transformed the building and demolition sectors. This cutting-edge method precisely and efficiently slices through concrete using a high-pressure water stream that is occasionally mixed with abrasive materials. Compared to conventional methods, it is a safer and more environmentally friendly choice because it can make clean cuts without producing heat or dust.

The versatility of waterjet cutting is one of its main advantages. From intricate architectural work to massive infrastructure projects, it is perfect for a variety of applications due to its ability to handle a broad range of concrete types and thicknesses. Waterjet cutting’s accuracy also lessens the need for secondary finishing, which saves time and money.

Another important benefit is safety. Waterjet systems, as opposed to mechanical cutting tools, don’t release dangerous dust or sparks, which lowers the possibility of fire and respiratory problems for employees. Additionally, by reducing vibrations, this technique can save nearby areas from structural damage and increase the equipment’s lifespan.

In conclusion, waterjet cutting concrete is a strong and effective technique with a lot of advantages. Modern construction and demolition projects can benefit greatly from its precision, safety, and versatility. Technology is expected to become even more essential to the construction industry as it develops, opening the door for safer, more effective, and cleaner building methods.

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