Mining Publication: A Practical Method of Measuring Shotcrete Adhesion Strength
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Original creation date: February 2010
The National Institute for Occupational Safety and Health (NIOSH) is conducting research to develop safe practices for the use of shotcrete as ground support in underground mines, particularly mines operating in weak host rock. As part of this research, tests were conducted with a commercial poly-fiber reinforced shotcrete mix to develop a practical means of measuring shotcrete adhesion strength. Full-scale tests were conducted in a test frame equipped with concrete panels having three distinct surface roughness profiles. Adhesion test fixtures either embedded or epoxied in the shotcrete were overcored into the underlying concrete, and direct tensile tests were conducted to determine the bond strength of the shotcrete cores to the substrate after a selected shotcrete curing interval (1, 3, 7, 14, 28, or 90 days). Measured adhesion strengths typically ranged from 0.5 to 2.0 MPa depending on the curing age of the shotcrete samples. This paper presents the results of these tests, describes the portable test system components, and addresses some of the design issues encountered in the development of a rugged and reliable method for determining shotcrete adhesion strength in underground mines.
Authors: JB Seymour, LA Martin, CC Clark, MA Stepan, RD Jacksha, RT Pakalnis, M Roworth, C Caceres
Conference Paper - February 2010
NIOSHTIC2 Number: 20036556
2010 SME Annual Meeting and Exhibit, February 28 - March 3, Phoenix, Arizona, preprint 10-137. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2010; :1-9
See Also
- An Analysis of Flexural Strength and Crack Width for Fiber-Reinforced Shotcrete Used in Weak Rock Mines
- Bending Fatigue Tests 2 and 3 on 2-Inch 6x25 Fiber Core Wire Rope
- Developments in Sealant Support Systems for Ground Control
- Early Strength Performance of Modern Weak Rock Mass Shotcrete Mixes
- The Long-term Performance of Surface Support Liners for Ground Control in an Underground Limestone Mine
- A Shotcrete Adhesion Test System for Mining Applications
- Technology News 434 - An 'Insulating' Shotcrete for Heat Abatement in Deep Mines
- Technology News 540 - Field-Expedient Shotcrete Adhesion Test System
- Technology News 542 - Field Use Round Determinate Panel Test System
- Tests of Fibre-Reinforced Shotcrete at the Chief Joseph Mine, Butte, Montana
- Page last reviewed: 9/21/2012
- Page last updated: 9/21/2012
- Content source: National Institute for Occupational Safety and Health, Mining Program