Project information
| Project: | Cleat protection Grube CLARA |
| Location: | Wolfach, Germany |
| Application: | Mining |
| Attribute: | Shotcrete |
| Mining material: | Fluorspar / Barite |
| Requirement: | Reduction of the dosage |
| Total volume concrete: | 4,000 m³ per year |
| Fibre type: | DE 35/0.55 N |
| Dosage: | 27 kg/m³ |
| Amount of fibres: | > 100to per year |
Special feature
to the Project
In Ground-Support protection, it is important to achieve safe and permanently reliable results when spraying the steel fiber concrete. An optimized concrete composition and coordinated fiber dosage is required.
Ground-Support with steel fiber concrete
Optimization of the results
The company Sachtleben Bergbau has so far used a steel fibre shotcrete with a dosage of 40 kg/m³ for the tunnel support in the mine “Grube CLARA”. The aim was to reduce the dosage rate and achieve at least the same performance. Numerous tests confirmed that the same or better results could be achieved with the steel wire fibre DE 35/0.5 N from KrampeHarex and a dosage of 26.7 kg/m³ or the DE 35/0.6 N with 33.3 kg/m³.
The steel fibre shotcrete is applied in the pit with a mobile sprayer with a smaller compressor to reduce dust generation and minimize fibre rebound. After the material is excavated and conveyed, the steel fibres are collected out through liquid separators and magnetic separators to obtain a pure product.
The concrete formulation considered and optimized consists of
425 kg of cement, 1,670 kg of sand and 210 kg of water. The w/c ratio is 0.5 and about 11% accelerator is dosed.
Do you have questions
about the project?
We look forward to hearing from you.
Your direct line
to KrampeHarex
Christian Braun
Projectmanagement Tunnel construction & Mining
