For over a century, Sika has been involved in highly challenging tunneling and mining projects around the globe. Sika supplies solutions for the largest and technically most complex projects - from below the Atacama Desert in Chile inside the large Chuquicamata block caving mine to the Gotthard base tunnel 2,500 meters below the Swiss Alps. All projects below ground have unique challenges and requirements. Together with our partners, we take on these challenges and implement tailored solutions for their specific technical requirements, environmental conditions and logistical hurdles.
Sika is at the forefront when it comes to efficiency improvements in tunneling and mining, reducing excavation times with faster shotcrete solutions and optimizing the cost performance of concrete in all underground operations. With a fully integrated and smart, high quality product portfolio, we are your ideal business partner to continue forging ahead in underground construction.
Sika Sprayed Concrete Solutions
Successful sprayed concrete requires the combination of many aspects of modern concrete technology especially concrete admixture chemistry, together with modern materials handling technology. The increasing demands for cost effectiveness and the protection of health and the environment mean that sprayed concrete has been in continuous development. Thanks to more than one hundred years of experience, expert knowledge and a focus on performance and economy, Sika is able to provide the newest generation of sprayed concrete solutions.
| Sika® Sigunit® | Shotcrete accelerators, available as liquid, powder or instant powder, for the highest strength development, ideal for overhead applications and building-up thicker layers. |
| Sika® ViscoCrete® Range | High range water reducing superplasticizers for better workability of the concrete mix, higher compressive strength and increased durability of the shotcrete. |
| SikaTard® | Cement hydration stabilizer to ensure long term stabilization of the concrete mix, enabling optimum shotcrete application with the highest flexibility - Always just in time. |
| SikaPump® | Pumping aids improve the pumpability of the concrete mix. For a smooth pumping process over long distances and time, with minimal friction and wear on the equipment. |
| SikaTell® | Colloidal silica additive for stabilizing the concrete mix cohesion and thereby reducing rebound and improving the long-term durability of the shotcrete. |
| SikaFiber® | Steel or synthetic fibers used to increase the resilience and energy absorption of the shotcrete. Highest performance with maximum efficiency. |
| SikaFume® | Micro silica additives that significantly improves the shotcrete and its durability: Optimum adhesion and minimal rebound, followed by watertight durability. |
| FlexoDrain | Substrate drainage system installed to allow the shotcrete application in case of moderate water ingress and protecting the lining from aggressive mountain water. |
| Aliva® | Specialist equipment for all types of wet and dry process shotcrete application and accelerator dosing. Off-the-shelf and tailor-made solutions. All Aliva® products for shotcrete applications, data sheets and more information can be found here. |
| SikaCare | Reduces the adhesion of cement mortar and concrete to the equipment, allowing extended use, lower wear and easier cleaning after the application. |
| SikaPump®-Start 1 | Lubricant for concrete pumps, significantly reducing the friction between concrete and hoses/pipes, during the start-up of the pumping process. |
| SikaShot® | Highly accelerated spray mortar for consolidating and pre-sealing the substrate. Ideal pretreatment under difficult conditions for the optimum shotcrete lining. |
Sprayed Concrete Has Many Advantages
- Application to any elevations because sprayed concrete adheres immediately and bears its own weight
- Can be applied on uneven substrates
- Good adhesion to the substrate
- Totally flexible configuration of the layer thickness on site
- Concreting without formwork
- Reinforced sprayed concrete is also possible (mesh/fiber reinforcement)
- Rapid load-bearing skin can be achieved without forms or long waiting times
Sprayed Concrete Applications
Sprayed concrete has a wide application range due to its high flexibility, good economics and good physical properties. However, the sprayed concrete method is requiring a high degree of mechanization and well trained nozzle operators. Nevertheless, the advantage over conventional concreting methods is outstanding: the application of concrete without any formwork. Sprayed concrete is mainly used in the following applications:
- Excavation stabilization in tunneling and mining construction
- Slope and trenching stabilization
- Protective lining
- Concrete repair (concrete replacement and strengthening)
- Special lightweight load-bearing structures
- Restoration of historic buildings (stone structures)
- Sealing works
- Construction of swimming pools
Requirements for Sprayed Concrete
The multiple demands placed on sprayed concrete today no longer allow standard solutions. Dependent on the spray process and the type of structure, different conditions are imposed on the sprayed concrete during application and in service.
In tunnel construction sprayed concrete is normally used for excavation stabilization, in open-pit mining and on major construction sites it is typically used for rock and soil stabilization on slopes. In bridge and other civil engineering repair and refurbishment works, sprayed concrete is often used specifically because formwork can thereby be dispensed with.