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Are you thinking of building a new pool? You must have come across several options for the methods to choose. Which were the two most prominent ones out of the lot? That’s right, Shotcrete and Gunite are the two best ways that we use to build concrete pools.
The basic difference between the two methods relates to the time when we add water to the concrete bed of our pool. Gunite is the term used when we refer to the dry mix of the concrete. Shotcrete, on the other hand, refers to the wet concrete mix.
In Shotcrete vs Gunite, the two mixtures contain aggregate, sand, and cement in almost the same quantity. However, when it comes to water, the proportion and the method of mixing change. The method that uses Shotcrete has a cement truck already mixing water. The mixed product sprays out of the hose into the pool bed.
On the other hand, Gunite, which is the dry mixture, will have the water combined at the opening of the nozzle. The water and concrete combine when we spray them.
To choose the right one for your use, it is crucial to understand their application, advantages, and disadvantages. To know more about Shotcrete vs. Gunite, read below.
Application of Shotcrete
Shotcrete mix means wet. For this to prepare, you need to have a mixture of concrete that is thoroughly mixed. Once done, the cement truck delivers the wet mix. For this process, you use a compressed form of air to shoot out the concrete.
The compressed air provides enough pressure for the concrete to combine with water. This is done at a very high speed to make the process quick and easy.
Advantages of Shotcrete
Since Shotcrete is applied at high pressure and speed, and you can complete it quickly. Depending on the number of materials you use, the entire mixture dries up.
Lesser Weak Spots
As Shotcrete uses water in its mixture, the resultant is less rigid and brittle. The materials can mold into each other easily and make the mixture flowy. Therefore, this ensures there are no gaps in between the materials and thus has reduced weak spots.
Another advantage of using Shotcrete while comparing Shotcrete vs. Gunite is that it comes premixed. This gives a lot of time for all the constituents to settle down and mix well. This produces a strong coat that is consistent too.
Requires Unskilled Labor
As the mixture is easy to handle and is pre-mixed, you eliminate the need to have a skilled set of labor. Therefore, the crew only has to apply it to places without having to get into technical details.
Mixes Admixtures Well
Due to the already present water in this concrete mixture, we can easily add admixtures that could improve the properties of the material. The admixtures form an even paste and do not change the thickness of the concrete.
Disadvantages of Shotcrete
In Shotcrete vs. Gunite, Shotcrete has a disadvantage due to its added water. As there are always chances of the water evaporating after the application, it may leave cracks.
This happens because by adding water, we increase the volume of the mixture, but due to evaporation, the spaces stay empty and thus form cracks.
Less Application Times
Shotcrete mixture arrives premixed at the site. As they already have the mixture ready in perfect proportions, the site crew is left with less time for any last-minute changes or decisions.
They are then required to apply the mixture as quickly as possible before the water dries up, or the mixture changes its property.
When compared to Shotcrete vs. Gunite, the production of cost of Shotcrete stands higher. As the factory unit requires to add the exact proportion of water to concrete, this marks for extra labor charges than Gunite.
Changes the Final Product
Another disadvantage of Shotcrete is the probable need to add water on site. If the application time is higher, the water in the mixture will dry up. As a result, the site crew will have to add water again, which changes the property of the final product too.
Shotcrete is weaker than Gunite. The possible reason for this disadvantage is the already present water that takes up a percentage of volume and reduces the strength of the product.
Application of Gunite
To apply a coat of Gunite, you first need to load the dry mixture in your hose. You store the hose with highly compressed air that you use to shoot out the concrete mix. As the mixture starts to come out of the nozzle, you add water to its mouth.
You create the wet mixture and use it as a coating on the pool bed. To check on the water level, you can use the nozzles of water and concrete.
The amount of water you add can vary depending on the mixture and the type of pool you want. As you add more water, the resulting mixture starts getting more consistent and compressed.
Advantage of Gunite
As the mixture is already dry, when you lay it on the pool bed, it gets harder as the crew cures up the bed, the chances of the mixture remaining hard stay. The amount of water you use while curing should be closely taken into consideration so that the property of the mixture stays.
More Application Time
Since you add the water on-site, it gives more time to the crew. If there are any last-minute changes or discussions, the mixture can wait. This will not disturb its consistency and properties.
Due to the addition of water after preparing the mixture, we get a smoother finish. This is because the dry mixture gets more time in settling, and the water makes a layer over it. As a result, we get a shinier and smoother surface of the pool.
In Shotcrete vs. Gunite, Gunite wins in strength. This is because the dry mixture gets sufficient time to settle and form strong bonds. When you add the water at a later stage, it is not able to disturb the main bonds and thus disturb the strength.
Disadvantages of Gunite
Chances of Error
The resultant mixture in Gunite is not factory-made. The crew chooses the amount of water and dry mixture that gives the final product. This gives more chances of error and may disturb the accuracy. Moreover, figuring out the exact amounts can also take up a lot of time.
Chances of Weak Spots
When we lay an additional layer over a mixture, the two layers don’t settle homogenously. There are always chances of weak bonds. This leaves several weak spots and thus hampers the entire mixture.
Choosing one option between Shotcrete vs. Gunite should depend on several factors. Expenditure, site, quality of crew, etc., are important should stay in mind while making your choice.
As the pros and cons of each are present above, go through them carefully, and plan according to the factors that matter to you. Moreover, if you have the right expertise and crew, any of the options would suit you and built you a strong pool with no struggle.