The shotcrete It's yet another example of the endless possibilities that concrete offers; it's worth learning more about it.
Thanks to its versatility and the nearly endless possibilities for modifying the concrete mix, you can find a wide variety of a variety of uses and techniques for applying it. One of them—and one of the most unique—is shotcrete or shotcrete; very used as an additive or soil amendment and to facilitate the construction of other elements.
The term “shotcrete” comes from the English vocabulary, specifically from the term “”Gun" what does that mean “gun” in Spanish, referring to the tool or machinery used to pour the concrete in this technique. This technique is already widely used in the construction of swimming pools, and it is becoming increasingly common in the slope preparation and land for construction.
What is shotcrete?
As you might guess, this technique involves spraying concrete using a “canyon” o high-pressure hose on a surface, whether even or uneven, to create a layer of concrete that levels it out or seals it against water. Creating a new surface with low porosity, with a thickness that can be very thin if required, or, conversely, quite thick; this always depends on the number of layers of shotcrete applied.
Contrary to what one might expect, even when applying a thin layer of this type of concrete It provides excellent strength, without using any formwork or steel reinforcement, yet, A reinforced structure can be used for more demanding applications. On the other hand, it is necessary to have additives that accelerate setting shotcrete, to prevent the concrete from shifting due to gravity before it bonds to the surface.
Shotcrete slope in a tunnel. Ganivel
Concrete Shotcrete Machine: How Does It Work?
It's a machine that works quite simply. It uses a hopper where the dry ingredients for concrete are deposited, that is, cement and aggregates; water is mixed with these components at different points depending on the type of system used by the concrete spray machine. If water is added at the outlet nozzle, this is called “dry method”, when the water is added 5 or 6 meters from the nozzle, it is “semi-dry method”, and if it is mixed with water right from the hopper, it is called “wet process”.
Types of Shotcrete
Concrete can be sprayed in three ways using a shotcrete machine:
- High-speed shotcrete: This is the method used to achieve the highest degree of compaction for shotcrete. This is because the concrete is sprayed at high pressure through a narrow nozzle.
- Low-speed shotcrete: It is done using large-diameter hoses and a wide nozzle. Moderate pressure is used, which means the concrete is not compacted as thoroughly as it would be at high speed, but it is still able to settle into place.
- Transportation shotcrete: In this case, the shotcrete machine is used to propel the concrete over long distances to the point on the job site where it will be poured. It should be noted that the shotcrete machines used in this case have nozzles with a much larger diameter.
Concrete Sprayer. .Grunimar
Benefits of Shotcrete
Although it was invented in the early 20th century, the use of concrete shotcrete machines was limited to large-scale infrastructure projects, such as tunnels, due to their complexity and high cost. Today, it is a much more accessible technology which is increasingly used in conventional construction thanks to its many advantages:
- Shotcrete has a very good adhesion on many types of surfaces: concrete, tile, rock, soil, and steel. Always keeping in mind that The surface must be clean.
- Since this mixture requires water to be added throughout the entire process, Its strength properties exceed those of conventional concrete manufactured at the plant.
- You save on formwork costs, since its consistency allows it to set on the surface where the concrete is poured. In many cases, it is not even necessary to use electro-welded reinforcing mesh.
- Thanks to its versatility It can be applied to any surface no matter how uneven it may be, and easily adjust the amount of concrete applied.
- Once the shotcrete has been applied, it has a very long service life over time and requires little to no maintenance.
In short, this technique is very useful for preparing slopes, swimming pools, and even in repairs to existing buildings where there is neither space nor time to maneuver, achieving superior quality. Investing in shotcrete can be a very smart decision, considering the time savings and improved durability, preventing moisture leaks and future damage.
