Performance comparison between thin spray-on liners with different compositions

Authors: Chang, S-H; Choi, S-W; Lee, C; Kang, T-H; Kim, J; Choi, M-S Download Paper

DOI https://doi.org/10.36487/ACG_rep/1710_05_Chang

Cite As:
Chang, S-H, Choi, S-W, Lee, C, Kang, T-H, Kim, J & Choi, M-S 2017, 'Performance comparison between thin spray-on liners with different compositions', in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 79-85, https://doi.org/10.36487/ACG_rep/1710_05_Chang



Abstract:
Four thin spray-on liner (TSL) mixtures were produced and tested based on the performance requirements specified by EFNARC (2008). They generally showed good tensile and bond strengths; however, one powdertype TSL mixture was shown to be unsuitable as a permanent support member (a ‘Class S’ TSL), because its elongation at break was much lower than the EFNARC (2008) specification. Two-component TSLs consisting of a liquid polymer and a powder binding material were more ductile and generally performed better than the one-component powder mixtures. Their high ductility resulted in increased elongation at break, even though their tensile strengths were slightly lower than those of the one-component powder TSLs. One prototype two-component TSL produced here satisfied every criterion specified by EFNARC (2008). Notably, it increased the average compressive strength of mortar specimens by over 20% even when coated to a thickness of only 3 mm.

Keywords: thin spray-on liner, one-component, two-component, rock, support

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