Types Of Gunite and The Best Applications Of Gunite in Construction Projects
TweetWhat is Gunite
Gunite can also be termed as sprayed concrete.Gunite is a method by which Concrete is sprayed into place rather than the more conventionally used pouring or placing into formwork. Gunite is the dry mixed form of Sprayed Concrete. It mainly consists of Fine particles in it's mix. While processing the application of Gunite the builders load pre-mix dry materials in the delivery equipment. In the next step compressed air is then sent through a nozzle where it is blended with water to hydrate the cement. After the mixing It propels out from the? spraying nozzle as super strength which enhances to compact the material.
Gunite Vs Shotcrete
Gunite and Shortcrete consist of a mix of sand, Aggregate and Portland Cement.However for composing Gunite Water is added to the dry concrete mix at the gun shaped nozzle opening. The concrete is made in the air right before hitting the target.
Shotcrete on the Other hand is a wet concrete mix, this mixture is sprayed in high pressure on the surface.The shotcrete process can be done with dry or wet mix and hence can be called as dry mix shotcreting and wet mix shotcreting.
Types of Gunite - Dry Mix And Wet Mix
The two best methods of applying Gunite is the dry mix process and the wet mix process.
Dry Mix Process
In this method portland cement and wet aggregates are blended well and then placed into a device that meters the mixed component into a stream of Compressed air.Material is carried by the compressed air through a delivery hose to the nozzle where water is added under pressure through a perforated ring.The water thoroughly moisturises the other ingredients as the mixture is jetted from the nozzle at a very high velocity onto the surface which needs to be shotcreted.
Wet Mix Process
In the wet mix process all the ingredients like cement and other aggregates and blended to create a mortar or a concrete. The wet concrete is delivered by a cement truck. The concrete sprays out at such a high speed that it bonds to itself where it is applied.
Advantages of Wet Process
- It requires Little or No formwork
- It is a cost effective method? for placing concrete.
- This specific process is quintessential for irregular surface applications and allow easy material handling in remote areas.
Advantages of Dry Process
- This is the most ideal product for cleaning and easy to start up and shut down.
- In this process one can get onsite control of materials.
- There is a limitation of the nozzle delivery equipment,the nozzle can move the gun to 1000 feet? horizontally and 500 feet vertically.
Application Tips for Using Gunite
The selection of Gunite for a particular application? should be based on Knowledge ,experience and a careful study of required? and achievable material performance.The success of the gunite? for that application is contingent upon proper planning and supervision, plus the skill and continuous attention provided by the Gunite applicator.
Pools and Tanks
A Gunite Pool can take between 4 to 6 weeks for completion. The reason this may seem long when compared with other inground pool options is because of the time taken to set the Gunite. Gunite is exclusively used to construct concrete swimming pools. More recently large aquariums have been constructed using Gunite.
Floors and Walls
Gunite floors in tanks and pools on well compacted sabbase or on undisturbed earth have generally delivered perfect service.Vertical and overhead construction of walls and slab columns and other structural members has been Gunited.
Slope Stabilization
Gunite is often used for Temporary protection of exposed rock surfaces that will deteriorate when exposed to air. Gunites are especially used to permanently cover the slopes or cuts.To prevent? damage from excessive? uplift pressure slope protection must be properly drained in.To prevent surface water infiltration , application of Gunite is always beneficial as it enhances the smoothing effect to the waste areas and also the the surface landfills.
Gunite Domes
Construction Techniques using inflatable air forming systems have made the construction of shotcrete cells or domes practical. These large structures have been used for residential housing ,warehousing bridge and culvert applications.
Dams
The exclusivity of Gunite is it is a concrete mixture with a very low water to cement ratio, granting the structure low absorption levels, and since it consists of high concrete compaction, therefore reducing the likelihood of cracks.Another advantage of Gunite Dam is it is impervious to fluctuating weather condition and it can even resist certain chemicals from penetrating the shells,and contaminating the inner stored liquids.
With high compaction and steel-reinforced concrete making up the shell of the Gunite Dam, structural integrity and resistance to the elements are at the top of the list of benefits of this liquid storage tank. As a result, this tank is ideal for the storage of potable water, as it offers an effective barrier to any form of outside contamination. The Gunite Dam can also be used for manure storage, giving the farmer a viable method of storing and accessing liquid manure, virtually eliminating the risk of contamination.
Final Thoughts
The usage of Gunite without reinforcement should be limited to small or confined areas for gunite thickness not exceeding 20 mm.The details of such installation should be approved by the purchaser. During Guniting operations, the equipment should be grounded in locations where there is a possibility of flammable materials being present.
The reinforcement should be placed not less than 13 mm from the surface to be gunited and there should be a minimum of 20 mm between the reinforcement and the final surface of the gunite.
Properly applied Gunite is structurally sound and durable construction material which exhibits excellent bonding characteristics rock steel and many other materials. It can have high strength, low absorption, good resistance to weathering and resistance to some form of chemical attack.Improper application of shotcrete may create conditions much worse than untreated conditions.
