CONCRETE

[:ru]Голицынский Д. М.[:en]Golitzynski D. M.[:] [:ru]доктор технических наук, профессор[:en]PhD, professor[:]

Alitinform №3-4 (04-05) 2008 г. 87-94 p.

Abstract

Air-placed concrete (spritzbeton, gunite, shotcrete, sprayed concrete) is a high-strength concrete obtained as a result of base mixture spreading by compressed air onto working surface. Base mixture consists of cement, filling aggregate (sand, gravel or crushed stone), water and, usually, a special additive to accelerate setting and hardening.

The process of concrete spraying is a further development of guniting method that is characterized by a significant amount of rebound (up to 30%) and dust-forming (Pic. 1).

The guniting method is known from the beginning of XX century when American inventor C. Akeley in year 1911 had patented the first «Cement-Gun» machine.

Since 1918 in USA the studies of gunite features were carried out that become the basis for practical use of this concreting method in construction.