Sökning: "Shotcrete"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet Shotcrete.

1. 1. Structural behaviour of shotcrete in hard rock tunnels

   Författare :Andreas Sjölander; Anders Ansell; Richard Malm; Fredrik Johansson; Eivind Grøv; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shotcrete; structural behaviour; material models; rock support; bond strength; fibre-reinforcement; Concrete Structures; Betongbyggnad;

   Sammanfattning : Tunnels in hard and jointed rock are normally excavated in an arch shape to enable the rock mass to support its weight. Since the beginning of the 1980's, fibre reinforced shotcrete (FRS) in combination with rock bolts have been the dominating support method for hard rock tunnels. LÄS MER

3. 2. Models for analysis of shotcrete on rock exposed to blasting

   Författare :Lamis Ahmed; Anders Ansell; Erik Nordström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shotcrete; Rock; Vibration; Stress waves; Numerical analysis.; Sprutbetong; Berg; Vibrationer; Spänningsvågor; Numerisk analys.;

   Sammanfattning : In underground construction and tunnelling, the strive for a more time-efficient construction process naturally focuses on the possibilities of reducing the times of waiting between stages of construction. The ability to project shotcrete (sprayed concrete) on a rock surface at an early stage after blasting is vital to the safety during construction and function of e. LÄS MER

4. 3. Time dependent material properties of shotcrete for hard rock tunnelling

   Författare :Lars Elof Bryne; Anders Ansell; Wolfgang Kusterle; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shotcrete; rock; granite; bond strength; compressive strength; pullout testing; failure modes; interfacial transition zone; micro structure; ettringite; set accelerator; shrinkage; drains; glass fibres; laboratory testing; tunnels tunnelling;

   Sammanfattning : In this thesis different mechanical properties for shotcrete (sprayed concrete) such as compression strength, bond strength, bending tensile strength, elastic modulus, free and restrained shrinkage as a function of its age was investigated. One of the main issues was to investigate the difference between ordinary cast concrete and shotcrete. LÄS MER

5. 4. Analyses of shotcrete stress states due to varying lining thickness and irregular rock surfaces

   Författare :Andreas Sjölander; Anders Ansell; Richard Malm; Fredrik Johansson; Jan Alemo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shotcrete; cracking; shrinkage; block load; varying thickness; numerical simulations; fibre reinforcement; Byggvetenskap; Civil and Architectural Engineering;

   Sammanfattning : Shotcrete is sprayed concrete applied pneumatically under high pressure and was invented in the beginning of the 1900's. This new technique decreased the construction time and since steel fibres were introduced in the shotcrete during the 1970's, shotcrete has been the primary support method for tunnels. LÄS MER

7. 5. Interaction between shotcrete and rock : experimental and numerical study

   Författare :Lars Malmgren; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

   Sammanfattning : At LKAB’s underground mines in Malmberget and Kiruna in northern Sweden shotcrete and rock bolts are the main rock support elements. A safe working environment for the miners and high accessibility to the mine are important issues. LÄS MER