Using compressed air, shotcrete is a form of low-slump concrete applied pneumatically onto a surface. It features a relatively low water/cement ratio, elevated cement content, and typically includes small aggregates, usually no larger than pea gravel. It routinely attains high compressive strengths surpassing 5,000 psi. Thanks to its adhesive qualities, shotcrete can be effortlessly placed on vertical and overhead surfaces without the requirement for formwork. Employing stringent quality control measures allows for the construction of a wall surface with a thickness of 8 inches or more in a single application.
As a proficient shotcrete contractor, Schnabel specializes in using shotcrete for the construction of temporary and permanent facings in soil nail retention walls. This adaptable material is not limited to soil nail walls and can serve as a facing for various earth-retaining wall types. In the context of soil nail walls, a temporary shotcrete layer of 4 to 6 inches is directly applied to the excavated ground surface. In the case of permanent walls, an additional 6 to 12 inches of reinforced shotcrete is applied after the installation of soil nails and the initial shotcrete layer. The final finish of the permanent facing can range from sculpted and stained to gun-finished or finish-troweled, resembling a formed concrete wall.