Instead of adding air at the nozzle as in wet-mix shotcrete
or water at the nozzle as in dry-mix shotcrete, the concrete mixture is pumped to a nozzle that spins at speeds up to 5,000 rpm and sprays the concrete onto the surface.
In wet-mix shotcrete
, the nano-silica's spontaneous binding capacity enables nozzlemen to reach a specified lining or cover thickness in fewer passes versus application of a conventional silica fume mix.
Yun, "Air-void structure, strength, and permeability of wet-mix shotcrete
before and after shotcreting operation: the influences of silica fume and air-entraining agent," Cement and Concrete Composites, vol.
Typically, a wet-mix shotcrete
process generates less airborne particles and rebound (waste) than gunite, simply because the material has 100% of the moisture added to it.
Had cracks in the underlying concrete been sealed properly to stop leaks, and had wet-mix shotcrete
been applied by a well-trained, conscientious crew, city officials likely would have gotten the results they wanted.
has been specified for the final shaft lining, and the local subsidiary of Swiss-based specialist supplier, MBT, won a R1.5 million contract to provide materials and admixtures for the shotcrete.
Pumping process is the first phase ahead of spraying concrete to a substrate, which is very important for wet-mix shotcrete
. However, blockages, leading to low work efficiency and causing the danger of pipe explosion in site, occur occasionally during pumping process, especially at the stage of startup if the lubricating layer that generally forms between the pipe and the material bulk was broken or not formed [1, 2].
Atlas Copco's self-contained, mobile MEYCO Versa concrete spraying system allows wet-mix shotcrete
to be applied accurately underground by a single operator.
mainly evaluated the pumpability of wet-mix shotcrete
including various admixtures, that is, silica fume, fly ash, ground granulated blast furnace slag, metakaolin, and steel fibers based on rheological properties.
DICOM applies mechanized, wet-mix shotcrete
, working with Putzmeister machinery.
Pumpability and shootability are important functional parameters considered in the design procedure for wet-mix shotcrete
(WMS) mixtures .
In 1993, Inco successfully introduced wet-mix shotcrete
as a replacement for dry shotcrete at its Frood mine, adjacent to Stobie, as a principal means of support in challenging ground conditions.