Utveckling av tätningskomponent/teknik för korrosionsskydd av bergbultar
The project addresses one of the main critical issues that has been repeatedly acknowledged in rock support systems: corrosion and consequently failure of the rock bolts in Swedish mining and tunneling industry. Defective installations of rock bolts occur frequently in form of voids in the cement-based material that is supposed to cover the steel bolt close to the tunnel wall to prevent from corrosion. Voids in the cement-based material are permeable to water and suspend the protection. The current installation process consists of several steps with heavy and dirty labor works and the process is repeated frequently. The difficult and uncomfortable work conditions in the tunnel, where the cement-based material is manually applied working mostly overhead, lead easily to execution errors. Moreover, adequate quality control of the execution is hardly possible.
The main objective of the project is therefore to develop a paper packet filled with sufficient amount of non-shrinking cement-based material that is used as corrosion protection at the exposed parts of rock bolts. The hydration process of the cement is started by immersing the paper bag in water. The final solution should be easy and cost efficient to produce, easy to install without need for specific equipment. Use of the new method should simplify the production control and documentation during the construction. Furthermore, it should reduce the material waste and enhance the productivity compared to the existing technologies.
Concerning the working environment, the new technique is anticipated to decrease the physical work load, risk of contamination, and finally, the mental stress of the laborers due to the improved manufacturing process. The final product should fulfill the design requirements, especially the designed service life, reduce the need for inspection and maintenance during the operation and consequently the life cycle costs.
RISE, Research Institutes of Sweden AB
Ali Nejad Ghafar, email@example.com