When the existing concrete structure is properly chipped or prepped, the newly applied shotcrete adheres easily to the concrete structure due to the force of the pneumatic application, small particle size used in the aggregate, and lower water-cement ratio. The shotcrete enters the pores of the chipped concrete and "grabs" on well. No bonding or [...]
Both place concrete by pneumatically projecting the material from a hose. The difference is when water is added to the material. In a wet-mix application, all materials - including cement, aggregate, ad-mixture and water - are mixed together before being pumped through a hose and pneumatically projected. Typically, a concrete truck supplies the wet-mix and [...]
There is really no difference between shotcrete and gunite and the terms can be used interchangebly. Shotcrete has been used as a generic term to describe the process of pneumatically applying concrete. Recently, some have defined shotcrete as utilizing wet-mix application and gunite as utilizing dry-mix application.
While this situation can occur, it is rarely due to an inappropriate use of shotcrete. Usually, shotcrete is chosen in situations that demand its superior compressive strength, excellent bond, prevention of corrosive agents, or ability to be applied under severe access and environmental conditions. If a shotcrete project begins to "fall apart" in a few [...]
Shotcrete is generally stronger than poured concrete because the method of pneumatically applying concrete reduces the water-cement ratio. Shotcrete typically reaches a strength of 3,000 psi in 24 hours or less, and a 28-day strength of 5,000 psi or greater. Ad-mixtures, such as silica fume, can increase the strength to as much as 8,000 psi.
The durability of shotcrete is equivalent to high-quality concrete. The life span of a new construction shotcrete structure is more than 50 years. For rehabilitation projects, shotcrete can extend the life of a structure by more than 25 years. Keys to a long-lasting product are 1) proper surface preparation, 2) appropriate aggregate and ad-mixtures, 3) [...]
Access, strength, prevention of corrosive materials, cost, environmental, low-impact.