The terms Gunite and Shotcrete are synonyms. The insert shown briefly describes the history of Gunite and/or Shotcrete. ACI defines Shotcrete as–”mortar or concrete pneumatically projected at high velocity onto a surface.” Over the years Gunite and Shotcrete are terms used to describe a material or end product. In reality, Shotcrete is actually an application product as the end product is concrete. No more and no less.
The employees of Palmetto Gunite represent hundreds of years of combined experience in the industry and the ownership is entering the third generation of commitment to excellence in this field of construction and engineering.
As with cast in place concrete, the use of Gunite is limited only by the needs and imagination of the client and the design professional.
The following pages are filled with photographs of past projects Palmetto Gunite has successfully completed.
History of Shotcrete
“In 1910, a double-chambered cement gun, based on a design developed by Carl Akeley, was introduced to the construction industry. The sand-cement product produced by this device was given the proprietary name Gunite. In the ensuing years, trademarks such as Guncrete, Pneucrete, Blastcrete, Blocrete, Jetcrete, and the terms “pneumatically applied mortar or concrete” and “sprayed concrete” were introduced to describe similar processes. The early 1930′s saw the generic term “shotcrete” introduced by the American Railway Engineering Association to describe the Gunite process. In 1951, the American Concrete Institute adopted the term “shotcrete” to describe the dry-mix process. It is now also applied to the wet-mix process and has gained widespread acceptance in the United States and around the world. (ACI Committee 506 1966)
The 1950s saw the introduction of dry-mix guns, which applied mixtures containing coarse aggregate; wet mix shotcrete equipment; and the rotary gun, a continuous feed device. Many improvements were made to wet-mix equipment and materials in the 1970s and 1980s. These improvements allowed pumping low-slump concrete longer distances at greater volumes. These innovations enhanced the utility, flexibility, and general effectiveness of the process. The development of centrifugally applied concrete and low-pressure, low velocity wet-process mortar and concrete are not considered shotcrete in this guide because they do not comply with the current definition of shotcrete or they do not achieve sufficient compaction.” (ACI Compilation No. 6 1987)