Tweet Share

• Send by email

  Send by email

  

  Permanent rock boltswith100 -yeardesign life in contaminated ground

  When used as permanent tunnel support, rock bolts are now universally required to serve a minimum 100-year design life. A couple of options may be considered when designing permanent rock bolts using either Glass-Fibre Reinforced Polymer bolts or steel rebar. Whilst the industry standard steel bar bolt with double corrosion protection system offers suitable protection in non-aggressive environments, the use of traditional cementitious systems with Ordinary Portland cements can perform poorly, particularly in highly aggressive environments with high concentrations of ammonia salts or acidic environment. In these environments, the traditional cementitious grout itself may potentially break down well in advance of the required design life and therefore compromise the durability of the rock bolt and the bond between the rock and bolt and the grout and the bolt, thus, affecting overall structural performance. This paper will discuss overall alternative systems considered for permanent rock bolting but with a focus on alternative grouting for steel rebar bolts using recent advancement in cement technology with new types of pozzolanic based cement. This new technology has been originally developed for the wastewater industry and its application is now presenting an opportunity for rock bolt grouting in chemically aggressive environments. The paper will overview accelerated long-term testing which have been completed on the new technology and discuss their use in tunnelling projects.

  Recipient :

  Name ^* :

  E-mail address ^* :

  ^* Required fields

  Send   or  Cancel

• Print