폴리머 기반 박층 라이너의 초기재령 특성 평가를 위한 실험적 연구
An Experimental Study on the Evaluation of Early-Age Mechanical Properties of Polymer-Based Thin Spray-on Liners
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초록
폴리머 계열의 박층 라이너는 양호한 암반 조건에서 숏크리트와 철망을 대체할 수 있는 새로운 지보재로고려되고 있으며, 1990년대부터 광산의 안정성 확보를 위해 사용되고 있다. 하지만 TSL의 지보 성능을 평가하기위한 TSL의 특성에 대한 실험적 연구가 부족한 실정이다. 본 연구에서는 구성 성분이 다른 두 가지 TSL 재료에대해 재령 7일에 인장강도와 부착강도를 측정하였고, EFNARC(2008)에서 제시하고 있는 지지력 평가 시험도함께 실시하였다. 시험결과, 폴리머 함량이 높아질수록 재료의 인장강도는 높아지나 상대적으로 부착강도는작아지는 것으로 나타났다. 특히, 폴리머 함량은 상대적으로 작지만 시멘트계 성분이 포함된 TSL 재료의 경우에는 경화가 빠르기 때문에 부착파괴에 대한 저항성이 높게 나타났다. 이상과 같이 폴리머 함량에 따라 TSL의성능이 상이하게 나타남을 확인할 수 있었다.
Abstract
Thin Spray-on Liners(TSLs) based on polymer materials have been considered as an alternative to shotcrete and wire mesh in relatively fair rock conditions, and used in mines since 1990s. Nevertheless, Few experimental studies on their mechanical properties necessary for the evaluation of their bearing capacities as a support member have been carried out. In this study, tensile and bond strengths of two kinds of TSLs with different material compositions were measured at the age of 7 days. In addition, two kinds of bending tests proposed by EFNARC (2008) to simulate representative failure mechanisms of TSLs were carried out on the same materials and curing age as in tension and pull-out tests. From the tests, tensile strength of a TSL is shown to increase as its content of polymer is higher. In contrast, its bond strength seems to be in inverse proportion to its polymer content. Especially, the TSL material in which a cementitious component is included with relatively smaller polymer content shows a faster hardening characteristic which results in higher resistance to de-bonding between a TSL and a substrate. As a result, it is shown that the performance of TSLs might be dependent upon its corresponding polymer content.
참고문헌 (16)
- ASTM, "Standard Test Method for Tensile Properties of Plastics, D638-10", ~ (2010)
- Archibald, J.F., "Comparison of Reinforcement Benefits of Spray-on Linings in Side-by- Side Unconfined Compression Failure Tests on Rock", Proceedings of the 103rd Annual General Meeting of the CIM, pp.13~25 (2001)
- EFNARC, "European Specification for Sprayed Concrete", ~ (1996)
- EFNARC, "Specification and Guidelines on Thin Spray-on Liners for Mining and Tunnelling", ~ (2008)
- Lau, V., "Laboratory Investigation of Support Mechanism for Thin Spray-on Liners", Proceedings of the 12th International Conference of International Association for Computer Methods and Advances in Geomechanics(IACMAG), pp.1381~1388 (2008)
- 이규필, "숏크리트 품질관리를 위한 숏크리트와 암석의 부착력 평가 기법 비교", 대한토목학회 논문집C, 25(2C), pp.125~131 (2005), 대한토목학회
- Povin, Y., "Part 1: Thin Spray-on Liners(TSLs)-A Quick Reference Guide, In Surface Support in Mining", pp.3~43 (2004), Australian Centre for Geomechanics
- Roberts, R., "Time to look below the surface of membranes", pp.62~63 (2001), Australian Mining Monthly
- Spearing, A.J.S., "Proposed thin support liner definitions: performance categories, and test methods", Proceedings of the 3rd International Seminar on Surface Support Liners: Thin Sprayed Liners, Shotcrete and Mesh, Section 11 (2003)
- Saydam, S., "Ground Control-Use of Liner Support in Mining", Presentation file, MINE4300-GEOTECHNICAL ENGINEERING (2008), School of Mining Engineering, University of New South Wales
- Stacey, T. R., "Review of membrane support mechanisms, loading mechanisms, desired membrane performance, and appropriate test methods", The Journal of The South African Institute of Mining and Metallurgy, pp.343~352 (2001)
- Stern, J., "Investigation of the characteristics of thin spray liners(TSL's) and their use as an additional support medium in block cave mining", Proceedings of the 1st international Symposium on Block and Sub-level Caving, pp.217~238 (2007)
- Tannant, D. D., "Thin Spray-on Liners for Underground Rock Support", Proceedings of the 17th International Mining Congress and Exhibition of Turkey- IMCET 2001, pp.57~73 (2001)
- Tannant, D. D., "Thin Spray-on Liners for Underground Rock Support-Testing and Design Issues, In Surface Support in Mining", pp.51~59 (2004), Australian Centre for Geomechanics
- Tannant, D. D., "Laboratory test procedures for validating the use of thin sprayed-on liners for mesh replacement", Proceedings of Canadian Institute of Mining, Metallurgy and Petroleum 101st Annual General Meeting, pp.8~ (1999)
- Yilmaz, H., "Shear-bond strength testing of thin spray-on liners", The Journal of The Southern African Institute of Mining and Metallurgy, 107, pp.519~530 (2007)