Shotcrete delivers concrete efficiently and effectively. Similar in composition to standard concrete that is mixed on-site and pumped into forms to set, shotcrete is sprayed into place instead of poured. Due to its ability to place cement in multiple forms in tight spaces and across distances quickly, shotcrete construction in Portland has been popular for decades.
The Shotcrete Process
The shotcrete process was invented in 1907. Shotcrete technology has matured since its origins and now there are two main shotcrete methods – wet or dry. Both spray concrete hydraulically from a hose system and produce concrete with comparable properties to standard concrete. Dry shotcrete accelerates dry material with compressed air through a hose and combines it with water and additives as the dry material exits the hose. The wet shotcrete process mixes the concrete before entering a hose. This allows for specific, consistent ratios of additives and/or water for the concrete mixture. The premixed concrete also creates less dust and concrete rebound when hitting the target surface. As the results for both processes are similar, the decision between each process depends of the concrete needed, job site constraints, and preference of concrete contractor.
The Shotcrete Advantage
Formwork, the molds that concrete is poured into while it cures, can be up to 35%-50% of concrete construction costs for a project. The shotcrete process bonds concrete to rebar, reducing or eliminating the need to support the internal pressures present when concrete is placed. This creates formwork cost savings potentially over 50% compared to cast-in-place construction. The resulting shotcrete concrete is also very strong and can be applied quickly. As shotcrete reduces the internal pressures of the placed concrete, it is often used to create intricate concrete shapes.
Why an Experienced Shotcrete Team Matters
The dry shotcrete process leverages a nozzleman’s expertise to combine the dry mixture with water and/or additives and the speed as it leaves the nozzle. The mixture itself continues mixing as it hits the target surface. This degree of control allows for a nozzleman to react in real-time to the concrete’s placement and adjust levels if needed. Additionally, shotcrete requires different preparation such as tying rebar at crossing points to reduce vibration during application and allowing for proper rebar encasement by the concrete when applied. Experience in these details can make the difference between an on-budget, on-time project.
At The Conco Companies, we are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products. Our experience includes providing services for commercial, educational, parking, and other construction development as well as public works projects. Please contact us for more information about our full range of premium Portland area concrete services including shotcrete.