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), 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
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
ASTM International 2010, ASTM D638-10 Standard Test Method for Tensile Properties of Plastics, ASTM International, West Conshohocken.
Archibald, JF 2004, ‘Canadian laboratory and field testing’, in Y Potvin, D Stacey & J Hadjigeorgiou (eds), Surface Support in Mining, Australian Centre for Geomechanics, Perth, pp. 73–87.
Chang, SH, Choi, SW, Lee, C, Kang, TH, Hwang, GS, Kim, J & Choi, MS 2016, ‘Development and performance evaluation of a twocomponent thin spray-on liner to guarantee its homogeneous qualities and to reduce dust’, Tunnel and Underground Space, vol. 26, no. 5, pp. 441–453 (in Korean).
Chang, SH, Lee, GP, Han, JT, Choi, SW, Hwang, GS & Choi, MS 2015, ‘Development of a powder-type thin spray-on liner and its performance evaluation at different curing ages’, Tunnel and Underground Space, vol. 25, no. 3, pp. 293–302 (in Korean).
EFNARC 1996, European Specification for Sprayed Concrete, EFNARC.
EFNARC 2008, Specification and Guidelines on Thin Spray-on Liners for Mining and Tunnelling, EFNARC.
Lau, V, Saydam, S, Cai, Y & Mitra, R 2008, ‘Laboratory investigation of support mechanism for thin spray-on liners’, in NM Jadhav (ed.), Proceedings of the 12th International Conference of International Association for Computer Methods and Advances in Geomechanics, Curran Associates, New York, pp. 1381–1388.
Tannant, DD 2001, ‘Thin spray-on liners for underground rock support’, Proceedings of the 17th International Mining Congress and Exhibition of Turkey, Chamber of Mining Engineers of Turkey, Ankara, pp. 57–73.