Shotcrete/Gunite

What is Shotcrete, and where is it best used?

Shotcrete, sometimes called gunite, is a process where low moisture concrete is sprayed through a nozzled hose or gun at very high velocity onto a surface to form a specific structural shape such as walls, floors, and roofs. The target base can be made of rock, dirt, wood, steel, polystyrene, or any other type of material where concrete may adhere. The new wet surface is then troweled smooth, or if desired, textures and tints can be added to create a variety of design effects. At Thorcon, we work closely with geotechnical engineers to provide you with custom shotcrete solutions to fit your needs, and we service clients not only in Colorado, but also in the surrounding region. Please visit our gallery for a more intrusive look at the types of applications.

Properties

Shotcrete is wet mixed and delivered to the job site in a standard concrete mixer truck. It is mixed as concrete is at the batch plan to ensure a clean mix design and a homogenous mix as opposed to gunite.  It is then pumped, typically with a swing tube piston pump, from the truck through 2 inch hose to the nozzle, and shot onto the surface to be coated with high pressure air. Shotcrete has excellent bonding capabilities, and thus is much less susceptible to cold joint issues encountered with cast-in-place concrete.

Gunite is very similar, except the cement and aggregates are delivered to the nozzle dry, where the water is mixed during the application.

Uses

Shotcrete or gunite projects require the same types of reinforcement specified for conventional cast-in-place concrete, including deformed bars, welded wire fabric, and pre-stressing steel. The finished product—shotcrete—now possesses a compressive strength (similar to normal and high-strength concrete) and has very good durability, low permeability, excellent bond and limitless shape possibilities. These are the properties that allow shotcrete to be effectively used as a strong structural building material or shoring face material that is incorporated in most shoring projects.

Steep Slope Stabilization

Although the hardened properties of shotcrete are similar to conventional cast-in-place concrete, the nature of the placement process provides additional benefits, particularly on fast setting forms and complex shapes. Along with home construction, shotcrete is used to build foundation walls, swimming pools, enhance complicated landscaping water features, and for steep slope stabilization applications.

Because of varying climatic conditions, steep slope grades need to be secured and stabilized. Rocks, trees, and other debris can unearth and dislodge without warning and become extremely dangerous to humans and traffic. Fiber-reinforced shotcrete (FRS) is now being used for such slope stabilization work. The shotcrete can be textured or trowel-finished, and may have color added to the mix, or stained on after the fact to match existing conditions. The results have proven to be excellent for strength and endurance, while the aesthetics of the mountainous surroundings remain intact, protecting the public from sometimes deadly accidents of nature.

Thorcon Shotcrete and Shoring is a design-build geotechnical contractor capable of delivering extremely technical projects performed to the highest standards creatively, safely, and in a timely manner.  We are OSHA- and MSHA-Certified; we are trained, equipped and available for residential, commercial and governmental work. Contact us today to get started on your shotcrete or gunite project.