Seismic Retrofitting: Spending to Save
Seismic retrofitting work is most often concerned with saving lives. But in cases of infrastructure, or historic structures, saving the structure, and making sure that it can operate after...
Masonry Carries the Load
Engineers frequently have preconceived notions about building materials. Masonry, for example, is commonly selected by architects for its color and texture, rather than by engineers for...
Design and Uses of Reinforced Shotcrete in Underground Projects in Canada
The first use of steel fibre reinforced shotcrete (SFRS) in Canada was using the wet-mix process in the support of deteriorated ground in 80 year old railway tunnels in the Fraser Canyon,...
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...
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...
Fast Foundation for Soft Clay
This article describes the detailed foundation work and high-capacity piling design for a flue gas desulfurization (FGD) retrofit system for the Lambton Generation Station in Ontario,...
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