What is the purpose of shotcrete?

Shotcrete is a method of applying concrete projected at high velocity primarily on to a vertical or overhead surface. The impact created by the application consolidates the concrete.

Is shotcrete stronger than concrete?

What is Shotcrete? Frequently used in underground applications, shotcrete is a wet- or dry-mix concrete that is pneumatically propelled at high velocity through a hose and nozzle. And because the spray application process reduces the water/cement ratio, it’s generally stronger than CIP.

What’s the difference between shotcrete and concrete?

Traditionally, concrete has been poured from a ready mix truck onto a project site. It is either placed on the ground or into forms, and then vibrated to flush out air and to make sure that it is compact. Shotcrete involves applying the concrete after it is already mixed.

What is the difference between shotcrete and Gunite?

For gunite, water is added to the dry concrete mix at the gun-shaped nozzle opening (hence the name “gunite”). Shotcrete is different in that it is trucked to your property wet in a cement truck. The water and dry mix are combined prior to arrival and shot out of a nozzle premixed and ready to go.

What is a disadvantage to shotcrete?

The primary disadvantage of shotcrete compared to poured concrete is the amount of time that it takes when used for large foundations, structural piers, and other structures with large cross-sections, compared to using conventional forms for these large structures.

Can cement be sprayed?

There are many applications and uses for sprayed concrete. Dry process sprayed concrete: a predetermined dry mix of cement and aggregate is propelled through a spraying nozzle, where a finely atomised spray of water is added to the stream of materials to hydrate the cement.

Is shotcrete more expensive than gunite?

Cost. Because of the relatively simple construction process, gunite pools are generally noticeably cheaper than shotcrete or typical concrete pools. As with any pool project, potential delays or accidents may add additional time or money to the construction process.

How thick can shotcrete be applied?

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.

What are pools sprayed with?

Gunite and shotcrete are forms of pneumatically applied concrete, meaning they are sprayed on with a high-pressure air hose. Crews shoot the material over a reinforcing network of steel bars.

How do you make a shotcrete mix?

3. Shotcrete mix design

1. Gray to bone ratio. The ratio of cement to aggregate should be different according to the construction process.
2. Sand ratio. The sand rate should be controlled at 50\% to 60\%.
3. Water to cement ratio. The ratio of the water-cement ratio of the wet-spraying construction is from 0.42 to 0.50.

What are the advantages of wet shotcrete?

Less rebound The amount of water in the shotcrete mix, among other factors, influences rebound quantity. The wet-mix method provides more control over the shotcrete mix, reducing rebound in comparison to the dry-mix method.

Can you shotcrete over concrete?

Shotcrete can be either wet-mix or dry-mix concrete, as long as it’s shot out of a hose, Shot concrete. Gunite is also shot out of a hose, but it’s a dry mix until it’s applied. This might be a little confusing, so let’s dive deeper into the ways pool builders typically use these two terms.