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...
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...
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...
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....
A Review of Sprayed Concrete Linings Adopted at Dinorwig Power Station
Sprayed concrete was adopted extensively as one element of both temporary and permanent rock support during the construction of the 1800 MW Dinorwig underground power station in North...
Reinforced Shotcrete Linings as Part of an Integrated Support System Used in a High Stress Mining Environment
Shabanie and King Mines are situated in the Southern part of Zimbabwe, some 60 km apart and approximately 200 km east of Bulawayo. They are the largest underground operations in Zimbabwe...
Seismic Design Criteria for Transporation Structures
Presented is a discussion focusing on two critical issues which must be resolved when setting seismic design criteria for important transportation structures such as those supporting elevated...
Controlling the Seismic Behavior of Precast Concrete
Precast concrete has, through the years the years, acquired a bad reputation insofar as its ability to withstand earthquake is concerned. This reputation, though reasonably based, is not...
Design Criteria for Seismic Connections in Precast Concrete
The seismic behavior of precast concrete is contrasted with that of cast-in-place and the conditions that precast must satisfy are reviewed. Design criteria and possible strategies for...
Ductile Connections for Precast Concrete Frame Systems
This paper describes a research program to investigate the behavior of ductile connections between precast beam-column elements. The objectives of the program are to provide rational design...
Seismic Performance Behavior of Precast Concrete Beam-Column Joints
The experimental test program being conducted at the National Institute of Standards and Technology on 1/3-scale model precast concrete beam-to-column connections is summarized. The objective...
Seismic Response of Average High-Rise Building Structions in Japan
Dynamic characteristic models, representing average high-rise building structures in Japan, have been established through the regression analyses utilizing review documents of seismic...
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