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Shotcrete Overview | Repair & New Construction | Underground/Geotech | Refractory
In the early 1900’s, Carl Akeley, a famous hunter, naturalist and professor, devised a novel method of making plaster models of large animals for taxidermy work. He made a wire frame, and with a special gun he devised, sprayed plaster onto the frame by means of compressed air. The principle of Akeley’s method was to hold a supply of dry material in the gun, convey it to the nozzle with compressed air, and wet it with the proper amount of water as it was blown onto the frame. This resulted in strong, thin coatings that would not slump off the frame and eliminated the problem of the plaster setting up before it was fully placed.
The equipment then was used to patch deteriorated concrete with a sand and cement mix. The results were excellent, and in 1911, patents and trade names were issued for the "Cement Gun" which is what the equipment was called, and "Gunite," the material produced by the process.
Until the 1960’s all Shotcrete work was dry-process, using pressure-tank guns. During that decade, the rotary type of gun was developed. Today variations of these two basic designs are used for all dry-process applications.
The wet process also was developed in the 1950’s, with pressure tanks being used to force a stiff mortar through the hose. Additional air was added at the nozzle and the process came to be known as Shotcrete. The subsequent development of dependable concrete pumps of various types hastened the advancement of this technology, and today the wet process is widely used and favored for certain applications.
Repair & New Construction
Underground/Geotech
Refractory
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