Shot Crete

Shot Crete Uses

Landslide stabilization. Reactive soils. Hold downs. Wall Reinforcement. Internal layer for contiguous piers seals gaps between piers and provides a water barrier

Shot crete is the shooting of concrete onto a surface. The concrete mix can be wet or dry and propulsion provided by compressed air. Wet mix is referred to as shot crete and the dry mix , mixed with water at the nozzle as gunite. It is used to apply concrete to vertical, inclined or overhead surfaces.

Shot crete has the advantage of reduced costs [Formwork savings of 50 to 100% over conventional cast-in-place construction]  and the ability to construct straight, curved, and irregularly shaped surfaces while providing a durable concrete structure.

It doesn’t require form work and allows visual access to the working face so can be more cost effective, time and labour saving.  Concrete swimming pools are usually formed up this way as curves can be easily incorporated into the finished product.

 

Strength Benefits

Shot-creteing is one method of building  structures using a concrete mixture. A shot-crete mix ratio  is likely to exceed the compressive strength of most mixtures used for placed concrete components because the application of shotcrete requires a much lower water-cement material ratio than commonly found in residential floor/wall mixtures. A shot-crete mixture will have a water-cementitious material ratio of approximately 0.50, yielding a compressive strength of about 4000 psi at 28 days. Poured floor or wall mixtures have ratios of approximately 0.70 and compressive strengths of 2500 to 3000 psi. The lower cement water material ratios  mixtures produce other benefits such as reduced shrinkage and lower water permeability. Additionally, the greater compaction of shotcrete achieved through the velocity of placement improves compressive strength and durability of the concrete.
Videos

Shotcreting guniting work at NH.

http://www.shotcrete.org/whyshotcrete/index.htm

http://retainingwallsydney.com.au