wet mix process and dry mix process

1. PRESENTED BY :
NIRANJAN CHAUDHARY
UID: 18MCE1402
CHANDIGARH UNIVERSITY
NH-95 - Dyalpura Road, Ludhiana - Chandigarh State Hwy, Sahibzada Ajit Singh Nagar, Punjab 140413
Department Of Civil Engineering
SEMINAR TOPIC: SHOTCRETE TECHNOLOGY

2. SCHEME OF PRESENTATION
• Introduction
• History
• Classification of shotcrete
• Dry mix or wet mix?
• Preparation of surface
• Sprayed concrete eqipments
• Applications of shotcrete
• Rebound
• Dust development
• Conclusion
• References

3. INTRODUCTION
• It is a sprayed concrete
• Introduced to make the work easier and immediate.
• Domes are now much easier to construct
• Tunnel linings are also becoming easy.
• It can be impacted onto any type or shape of surface.
• This technology helps in completion of the construction in
very less time and the technique id unique.

4. • Make Effective Presentations
• Using Awesome Backgrounds
• Engage your Audience
• Capture Audience Attention

6. HISTORY
• was invented in 1907
• Akeley(May 19, 1864 – November 17,
1926).
• In 1911, he was granted a patent for
his inventions.
• Till 1950s only the dry-mix process
was used.

7. CLASSIFICATION OF SHOTCRETE
1. Dry process 2. Wet process
Dry mix shotcrete
• Cement ,sand and coarse aggregates(optional) are mixed .
• Mix is fed into delivery hose
• Mix is transforted by compressed air to the nozzle,where water is
introduced under pressure.
• Material is jetted at high velocity onto surface to be shotcreted

9. 2.Wet Mix Process
• All ingredients are throughly mixed.
• Mix is fed into delivery hose
• Mix is transported by compressed air to nozzle,where accelerator is added
• Additional air is injected to inrase velocity
• Material is jetted at high velocity onto surface to be shotcreted

11. DRY MIX OR WET MIX?

12. PREPARATION OF SURFACE
• The surface should be free from lose materials. It should be clean to
receive the shotcrete layers.
• In case the surface is smooth it should be roughened with sand
blasting. Otherwise the surface could be cleaned with air water jet.
• The time lag between the first layer and the second layer is to be
kept as minimum as possible.-say less than 8 hours.

13. CONCRETE SPRAYING
EQUIPMENTS
• Batching and mixing equipment
• Admixture dispensers
• Air compressor
• Nozzles

16. REBOUND
Factors influencing rebound quantity
• Nozzleman’s technical skill and experience
• Spraying direction
• Spraying parameters
• Spraying process
• Sprayed concrete mix design
• Sprayed concrete performance
• 5to 15% for horizontal slabs,15 to 30% for sloping,20to 50% for
overhead suface and corners

17. DUST DEVELOPMENT
Measures to reduce amount of dust for dry mix process
• Use of slightly moist aggregates
• Sealing the conveyor feeding system
• Use of alkali free shotcrete accelerators
• Correct adjustment of parameters at nozzle

18. APPLICATION OF SHOTCRETE
a)Repair
 Bridges
 Buildings
 Marine
 Spillways
b)Underground exavations
c)Slope and surface protections
d)New surface structures

19. CONCLUSION
• It is perhaps the most diverse method available for concrete construction.
• The use of this innovative technology is increasing day by day and procedures
for its proper performance are well developed
• high quality work is regularly obtained.
• The use of Shotcrete to build new concrete structures aswell as to restore and
repair existing structures is wellknown and documented.

20. REFERENCES
1] Advanced technology in civil engineering,chandra pratap singh,Nishant
rana,siddhant rana
2]Advancements in shortcrete technolgy,Antonella guide,Ippolita mecca
3]Advances in shotcrete technology for infrastructure rehabilitation,Dudley
R.”Rusty”Morgan
4]The development of sprayed concrete and C.T research,Ruyi wang,Ziyi
Hou,Jiliang Wang