High-Grade Concrete for the Single Permanent Shotcrete Lining Method
With the single permanent shotcrete lining method in underground construction in rock, a shotcrete layer placed subsequently to the application of the supporting shotcrete replaces the...
Technical Note: STC-40 Shotcrete Adhesion In Situ Tester
It is essential that the shotcrete when reinforcing the rock mass achieves a good adhesive bond to the rock surface. The strength of that bond can be controlled by pull out testing either...
Development of Mechanized Wet Mix Shotcrete Application in Norwegian Tunnelling Industry
From 1971 to 1980 wet mix shotcrete won the Norwegian market 100%. In the same period hand held spraying was replaced by hydraulic manipulators. From 1980 to 1986, steel fibre use increased...
Wet Mix Shotcrete Used in Subsea Tunnel Environments
To reject the claim that the use of accelerator in shotcrete reduces the compressive strength with time, lately cored samples were taken from an 18 to 19 years old concrete. A wet mixed...
Guidelines for Shotcreting and Current Development in the Wet-Mix Technique in Finland
Guidelines for shotcreting were written based on the literature survey and shotcreting trials. During shotcreting trials existing Norwegian and Middle-European wet-mix shotcreting concepts...
Practical Considerations on the Use of Additives for Shotcrete
Shotcrete is mostly used today for securing rock: in this capacity, it has solved many problems and has become a necessary aid. However, thedegree of utilization of the method is still...
The Influence of Water Glass on the Technological Parameters of Shotcrete
Shotcrete used in tunneling must follow a clearly defined early strength development in order to comply with stresses from rock deformations and drilling and blasting. Accelerators are...
New Advances in Shotcrete Additives: The DELVO System
The DELVO system is a two component, nonchloride chemical system developed to control the dynamics of cement hydration. Concrete, treated with the DELVO system, can be kept in a plastic...
New Developments in Tunnel Lining by Help of Steel Fibre Reinforced Concrete
The combination of single shell structures in tunnelling with the use of steel-fibre-reinforced concrete is decisively able to reduce the costs of tunnel projects. Several variants of...
An Identity Chart for Steel Fibers
Improvements in ductility and toughness by adding steel fibers to the shotcrete mix are sufficient to enable steel fibers to be used as replacement for steel mesh reinforcements. Steel...
Fire Testing of Shotcrete Samples in a Small Furnace
The fire resistance behaviour of 8 shotcrete samples were investigated in a laboratory furnace applying ISO 834 standard test. Shotcrete was applied on 20 to 30 cm thick granite slabs...
Use of Steel-Fiber Reinforced Wet-Mix Shotcrete in Extreme Rock-Bursting Conditions
If the stresses close to tunnels or caverns exceed the capacity of the surrounding rock, rock-bursting might start. When tunneling in such rock conditions the need for a safe, quick and...
Steel Fiber Reinforced Shotcrete?For Rock Support and Fire Protection
Rapid development in concrete technology and development of equipment has led to a change from dry hand-operated to wet robot shotcreting in Norway. Shotcrete of more than 100 MPa cube...
Use of Long, Variable Length Steel Fibres in Shotcrete
Steel wires are cut to fibres in a shotcrete nozzle and directly incorporated in the ejected shotcrete. Long and variable length fibres can be used. The fibre material is better utilized...
Steel Fibre Reinforced Wet Shotcrete with Very High Deformation Capacity
Tests have been carried out under site conditions in Norway where the performance of 40 mm long DRAMIX fibres was compared with normally used 30 mm fibres. The fibres were mixed into the...
Various Techniques for Fiber Reinforcement
Placing wire netting in thin shotcrete layers was found to be a difficult, dangerous and time-wasting method. Searching for other ways to reinforce the concrete, it has been found that...
Advances in Shotcrete Technology for Support of Underground Openings in Canada
This paper presents a broad overview of the state-of-the-art of shotcrete technology for support of underground openings in Canada. Advances in shotcrete technology such as the introduction...
Route 5: Steel Fibre Shotcreting in Shing Mun Tunnels Hong Kong?Specifying for Innovation
The Shing Mun tunnels form the central 2.6 km length of the Route 5 Highway connecting Tsuen Wan and Sha Tin New Towns, Hong Kong. The crossing of one of the areas was particularly difficult,...
The Introduction of Steel Fibre Shotcrete to Underground Cavern Support in Taiwan
The Mingten project is located in a sheared, sandstone rock mass near a regional fault. The design philosophy introduced steel fibre shotcrete as a permanent cavern support in Taiwan....
Fibre Reinforced Shotcrete Case Studies of Wet and Dry Processes
Both wet shotcrete and fibre reinforced shotcrete are being increasingly utilised in the South African mining industry. This Paper describes two applications of fibre reinforced shotcrete...
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