Isothermal Creep Behaviour Investigation of Thin Spray-On Liners

2017-06-28
Güner, Doğukan
Öztürk, Hasan
Rock supporting has a vital importance in longevity and sustainability of all underground openings. There are many types and forms of supporting systems available in the mining/tunneling industry. In the last decade, a new polymer-based surface support material, thin spray-on liner (TSL), has started to take place of conventional surface support materials. TSL is defined as generally cement, latex, polymer-based and also reactive or non-reactive, multi-component materials applied to the rock surface with a layer of few millimeter thickness. They have the advantages of low volume, rapid application and low operating cost. The majority of current TSLs are two-part polyurethane/polyuria or Portland cement based latex products that are mixed on site before spraying onto surfaces. They are now being considered for highly stressed, deep, rock bursting conditions as a reinforcement and retaining element together with bolts and screen. In this study, the creep behavior of a cement-based TSL was investigated. For this purpose, 7-day cured dogbone TSL specimens were tested under 23±2°C laboratory conditions. A range of dead weights (80, 60, 40, and 20 % of the tensile strength) were applied until the rupture of the specimens. As a result of this study, the time-dependent strain behavior of a TSL was presented for different constant load conditions. Moreover, a new equation was derived to estimate tensile failure time of the TSL for a given loading condition. If the tensile stress acting on the TSL is known, the effective permanent support time of the TSL can be estimated by the proposed relationship.
Citation Formats
D. Güner and H. Öztürk, “Isothermal Creep Behaviour Investigation of Thin Spray-On Liners,” presented at the 51st U.S. Rock Mechanics /Geomechanics Symposium (June 2017), California, USA, 2017, Accessed: 00, 2021. [Online]. Available: https://www.onepetro.org/conference-paper/ARMA-2017-0320.