We shall pour concrete in particular structural element by hand mix or ready-mix concrete. The shotcrete concrete is not one of those types of concrete.
Must Read: Properties of Concrete
By applying high-velocity pressure the concrete sprayed on a horizontal or vertical surface of structure through a nozzle is called Shotcrete concrete or a gunite concrete.
Sometimes instead of concrete, the mortar will also be applied on the structural surface.
Shotcrete Concrete Mix Design
- The mix ratio for shotcrete concrete is the same as what we use in conventional concrete.
- The mixing material and water-cement ratio may change since the shotcrete mostly used in the waterlogged area or seashore.
- The concrete mix design may change as per the requirement where it would be used!
- The components of the concrete mix shall be weight-batched before mixing by a proper weight watcher. Batch shall be based on the weight of single components with accuracy within ±1.0% of the values corresponding to the selected type of mix.
Reinforcement for shotcrete concrete
The reinforcement for shotcrete concrete depends upon the purpose of use because sometimes steel fabric wire will be used as reinforcement. Mostly TMT will be used as reinforcement.
When the shotcrete concrete applying in MS pipe, 13 gauge or 14 gauge steel fabric wire will be used as reinforcement.
- After selection of right materials, the material collected and dumped into the material pit of the shotcrete machine.
- The material mixed in dry condition and thereafter required water will be mixed.
- At right velocity, the concrete will be sprayed eventually on the specified surface.
- After spraying the concrete the surface levelled uniformly.
Uses of Shotcrete
- It is very effective in repair and rehabilitation works.
- We can pour concrete either on a horizontal or vertical surface.
- Mostly shotcrete used to construct a retaining wall where the soil is very loose.
- The shotcrete concrete is mainly used in underground oil line or water pipeline where the pipe is buried under the earth to avoid the pipe corrosion.
- To avoid internal damages of the surface.
Advantages and Disadvantages of Shotcrete
Advantages of Shotcrete concrete
- It can reduce manpower.
- Minimal formwork only required.
- Economically good compared to the conventional concrete.
- We can easily control the water-cement ratio.
- Cost friendly for the repair and rehabilitation work.
Disadvantages of Shotcrete concrete
- Material wastage may high compared to the conventional concrete method.
- High skill manpower required to do the job.
- The concrete smooth finishing work is a little complicated.