Concrete pools can be constructed with the shotcrete or gunite process. The difference is when the concrete mixes with the water. Shotcrete always refers to wet concrete that's already fully mixed before it's shot out of a hose.
Gunite generally lasts longer and maintains a higher quality than shotcrete. For instance, gunite tends to dry faster than shotcrete, leading to a much smoother surface and avoiding significant cracks from shrinking. Gunite can also withstand up to 9500 psi, a much higher psi than shotcrete.
Shotcrete is used to reinforce both temporary and permanent excavations. It may be employed, in concert with lagging and other forms of earth anchor, to stabilize an excavation for an underground parking structure or hi-rise buildings during construction.
Drawbacks of Shotcrete:
A more costly option than gunite. Operators may need to add water to the mixture to prevent it from hardening, which can compromise the strength of the final product.
In addition, shotcrete — while less expensive than poured concrete — is more expensive than gunite. Finally, shotcrete takes a significant amount of time as compared to poured concrete, making it a less than ideal choice for large foundations, structural piers or other large projects.
Concrete, Coping, & Tile
Next, your swimming pool / spa will be sprayed with a concrete substance of either shotcrete or gunite, which takes approximately 1-2 weeks to cure (or dry).
Sprayed concrete is the method by which concrete is sprayed into place, rather than the more conventionally used pouring or placing into formwork. According to the Sprayed Concrete Association other terms used include Gunite, Shot Concrete and Shotcrete. There are many applications and uses for sprayed concrete.
The current Indian shotcrete code, IS 9012 is not adequate to fulfil the requirement of the present scenario of sprayed concrete construction. The details about the mix design, usage of fibers, long term durability and standard testing procedures for shotcrete are deficient.
Shotcrete is pretty much the same thing as concrete (i.e. it is used ready mixed), but its name derives from the way it is applied. Instead of being poured, it is fired out of a hose at high speed (you can see how it gets its name!).
Shotcrete needs to be protected from rain until it obtains its final set, usually 4 or 5 hours. Following final set, it should be wet cured for at least 4 days, preferably 7 days if possible. The exposure to rain would prove beneficial as the rain would assure the presence of moisture for continued curing.
Structural shotcrete is a concreting method where shotcrete placement and finishing techniques are applied to structural applications in lieu of formed concrete construction.
Advantages of Using Concrete for your In-ground Pool
Using regular concrete for your in-ground pool has its advantages. They include: Concrete is pre-mixed, so there are no real concerns about finding the right ratio of materials. It forms a strong coating.
Shotcrete / concrete is ready for water as soon as the initial set is complete, which is about 4-6 hrs after placement. Water is applied to aid in hydration/curing, a process which decays exponentially, so watering is most critical in the first hours/days after placement.
Step 3. Spray the gunite surface evenly, with a hose and nozzle adjusted to a mist spray or gentle rain, at least four times a day for at least five to seven days. Stand on the edge of the pool to do this and do not walk into the pool or on the gunite surface for at least three days.
There is no stated maximum thickness for shotcrete used in shear walls or any other type of wall. Walls have been successfully placed to a thickness of 36 in. (914 mm) for some time. The two main concerns are the heat of hydration and proper encapsulation of the reinforcing steel.
Shotcrete is a mortar or high performance concrete conveyed through a hose and pneumatically projected at high velocity onto a backing surface. It is the force of this spraying action that leads to compaction of the concrete or mortar which then forms layers of concrete to the required thickness .
7.2.
Shotcrete typically consists of one part cement and four parts sand by weight with approximately 7% water by mass of dry ingredients. It can also include coarse aggregate and admixtures. Dry mix shotcrete involves the premixing of dry ingredients with water added at the nozzle.
This standard covers only the guidelines for guniting upstream face of masonry dams to give necessary guidance in this respect. This standard covers the general guidelines to be Water used for gunning should conform to the followed for guniting upstream face of masonry requirements specified in IS 456 : 1978.
The difference is when the concrete mixes with the water. Shotcrete always refers to wet concrete that's already fully mixed before it's shot out of a hose. Gunite is a dry concrete mix that only mixes with water at the end of the nozzle as it's being sprayed onto its final surface.
Gunite and shotcrete are two trade terms for different types of sprayed concrete. Sprayed concrete was developed as a construction solution for tunnels, underground structures, slope stabilization, structural repairs, and swimming pools.
Although fiberglass has been commonly use for insulation, spray foam can actually outperform it. Plus, with so many ways you can use expanding foam, this material certainly is handy. Now only if it could help us out with all of those concrete problems… Oh wait, it actually can!
A: The gunite shell must be maintained moist for at least 7 days after application is completed. The gunite should be sprayed with water using your water hose and spray nozzle. Gunite will cure better and properly if kept moist.
Shotcrete is applied pneumatically through the use of a pump, hose, and a specially designed application nozzle. The formula for concrete in a shotcrete application has a higher amount of cement and a lower amount of water than that of “cast-in-place” concrete.
Do not turn on waterfalls or fountains that aren't necessary until the start-up procedure has been completed. Do not swim in the pool until after the start-up procedure has been completed. Do not use any automatic pool cleaners for a minimum of three weeks after plastering.