Evaluation of Segment Lining Fire Resistance Based on PP Fiber Dosage and Air Contents

Soon-Wook Choi; Tae Sung Kang

doi:10.7474/TUS.2021.31.6.469

All Issue

2021 Vol.31, Issue 6 Preview Page Next Page

Original Article

Evaluation of Segment Lining Fire Resistance Based on PP Fiber Dosage and Air Contents 세그먼트 라이닝의 PP섬유 혼입량과 공기량 변화에 따른 화재저항 특성 평가

31 December 2021. pp. 469-479

PDF XML

Abstract

As a material for preventing spalling of concrete, the effectiveness of PP fiber has already been confirmed. However, it is necessary to consider the maximum temperature that occurs during a fire, and to solve the mixing problem and the strength reduction problem that occur depending on the mixing amount. In this study, the fire resistance performance of tunnel segment linings according to the PP fiber content and air volume under the RABT fire scenario was investigated. As a result, no spalling or cross-sectional loss occurred in all test specimens, and when the PP fiber content was small, the maximum temperature was relatively high and the maximum temperature arrival time was also fast. On the other hand, no trend was found for the maximum temperature and arrival time according to the difference in air volume. In the internal temperature distribution results for the PP fiber mixing amount of 0.75, 1.0, 1.5, and 2.0 kg/m³, the results of 0.75 and 1.0 kg/m³ showed similar temperature distribution, and the results of 1.5 and 2.0 kg/m³ were similar. It was confirmed that the internal temperature distribution tends to decrease at the same depth when the amount of PP fiber mixed is large, and it was confirmed that a remarkable difference occurred from the results of 1.0 kg/m³ and 1.5 kg/m³ of PP fiber mixed amounts.

Keywords

Tunnel

Segment

Fire resistance

PP fiber

Air contents

콘크리트의 폭렬방지 재료로서 PP섬유는 그 효과가 이미 확인되었다. 그러나 화재 시 발생하는 최대온도에 대한 고려가 필요하고 배합량에 따라 발생하는 믹싱문제 및 강도저하 문제의 해결이 필요하다. 본 연구에서는 RABT화재시나리오 하에서 PP섬유 함유량과 공기량에 따른 터널 세그먼트 라이닝의 화재저항성능을 살펴보았다. 그 결과, 모든 시험체에서 폭렬과 단면손실은 발생하지 않았으며, PP섬유 함유량이 작을 경우 상대적으로 최대온도가 높고 최대온도 도달시간 역시 빠른 것으로 나타났다. 반면, 공기량 차이에 따른 최대온도와 도달시간에 대한 어떤 경향을 발견하지 못했다. PP섬유 혼입량 0.75, 1.0, 1.5, 2.0 kg/m³인 경우에 대한 시험체 내부 온도분포 결과에서는 0.75와 1.0 kg/m³의 결과가 유사한 온도분포를 보였으며, 1.5와 2.0 kg/m³의 결과가 유사하게 나타났다. PP섬유 혼입량이 많을 경우 동일 깊이에서 내부 온도분포가 낮아지는 경향이 있는 것을 확인할 수 있었으며, PP섬유 혼입량 1.0 kg/m³와 1.5 kg/m³의 결과에서 주목할 만한 차이가 발생함을 확인하였다.

키워드

터널

세그먼트

화재저항

PP섬유

공기량

References

Beard, A. and Carvel, R., 2005, The Handbook of Tunnel Fire Safety, Thomas Telford Publishing, London, pp. 113-115. 10.1680/hotfs.31685

Chang, S.-H., Choi, S.-W., Kwon, J.W., Kim, S.H., and Bae, G.-J., 2007, "Alteration of mechanical properties of tunnel structural members after a tunnel fire accident", J. of Korean Tunn Undergr Sp. Assoc., 9(2), pp. 157-169.

Choi, S.-W., Chang, S.-H., Kim, H.Y., and Jo, B.H., 2010, "Assessment of Structural fire Resistance of a Fire-Proofed Immersed Tunnel Under Tunnel fire Scenarios", J. of Korean Tunn Undergr Sp. Assoc., 12(6), pp. 429-441.

Choi, S.-W., Kang, T.-H., Lee, C., Kim, H.S., Ahn, B., and Chang, S.H., 2021, "Fire resistance assessment of segment lining with PP fiber amount", J. of Korean Tunn Undergr Sp. Assoc., 23(5), 303-314.

Clement, F. and Focaracci, A., 2011, "Fire Protection in Tunnels: Requirements, Solutions and Case histories", Proceedings of ITA-AITES 2011, Helsinki, Finland.

Haack, A., 1998, "Fire Protection in Traffic Tunnels: General Aspects and Results of the EUREKA Project", Tunnelling and Underground Space Technology, 13(4), pp. 377-381. 10.1016/S0886-7798(98)00080-7

Hager, I., Mróz, K., and Tracz, T., 2019, "Contribution of polypropylene fibres melting to permeability change in heated concrete-the fibre amount and length effect", Proceedings of the IOP Conference Series: Materials Science and Engineering, 706(1), Montevideo, Uruguay, pp. 012009. 10.1088/1757-899X/706/1/012009

Hertz, K.D., 2003, "Limits of spalling of fire-exposed concrete", Fire Safety Journal, 38(2), pp. 103-116. 10.1016/S0379-7112(02)00051-6

ITA, 2004, Guidelines for structural fire resistance for road tunnels, Working Group No. 6 Maintenance and Repair, pp. 2-4~6.

Kalifa, P., Chene, G., and Galle, C., 2001, "High-temperature behaviour of HPC with polypropylene fibres: From spalling to microstructure", Cement and concrete research, 31(10), pp. 1487-1499. 10.1016/S0008-8846(01)00596-8

Khaliq, W. and Waheed, F., 2017, "Mechanical response and spalling sensitivity of air entrained high-strength concrete at elevated temperatures", Construction and Building Materials, 150, pp. 747-757. 10.1016/j.conbuildmat.2017.06.039

Khoury, G.A., 1992, "Compressive strength of concrete at high temperatures: a reassessment", Magazine of Concrete Research, 44(161), pp. 291-309, 10.1680/macr.1992.44.161.291

Khoury, G.A., Majorana, C.E., Pesavento, F., and Schrefler, B.A., 2002, "Modelling of heated concrete.", Magazine of Concrete Research, 54(2), pp. 77-101. 10.1680/macr.54.2.77.40895

Khoury, G.A., 2008, "Passive fire protection of concrete structures", Proceedings of the Institution of Civil Engineers-Structures and Buildings, 161(3), pp. 135-145. 10.1680/stbu.2008.161.3.135

KTA, 2008, 3rd Mechanized tunnel construction tunnel design service Technical Conference, KTA, pp. 457-458.

Mazzucco, G. and Xotta, G., 2016, "Fire spalling prevention via polypropylene fibres: a meso-and macroscale approach", Modelling and Simulation in Engineering, Volume 2016, Article ID 8639545, p. 11. 10.1155/2016/8639545

Melbye, T. and Dimmock, R., 2006, "Thermal Barriers and Fibre Concrete Roles in the Passive Fire Protection of Tunnels", In Shotcrete for Underground Support X, ASCE 2006, pp. 285-297. 10.1061/40885(215)23

Mindeguia, J.C., Pimienta, P., Carré, H., and La, C., 2009, "Experimental study on the contribution of pore vapour pressure to the thermal instability risk of concrete. Concrete spalling due to fire exposure", In Proceedings of 1 st International Workshop on Concrete Spalling due to Fire Exposure, Leipzig, pp. 150-167.

Phan, L.T., 1996, Fire Performance of High-Strength Concrete: A Report of the State-of-the-Art, NISTIR 5934, National Institute of Standards and Technology, pp. 54-56. 10.6028/NIST.IR.5934

Schneider, U., 1988, "Concrete at high temperatures-a general review", Fire safety journal, 13(1), pp. 55-68. 10.1016/0379-7112(88)90033-1

Wang, P., Jiang, M., Zhou, J., Wang, B., Feng, J., Chen, H., Fan, H. and Jin, F. (2018), "Spalling in concrete arches subjected to shock wave and CFRP strengthening effect", Tunnelling and Underground Space Technology, 74, pp. 10-19. 10.1016/j.tust.2018.01.009

Yermak, N., Pliya, P., Beaucour, A.L., Simon, A., and Noumowé, A., 2017, "Influence of steel and/or polypropylene fibres on the behaviour of concrete at high temperature: Spalling, transfer and mechanical properties", Construction and Building Materials, 132, pp. 240-250. 10.1016/j.conbuildmat.2016.11.120

Information

Publisher :Korean Society for Rock Mechanics and Rock Engineering
Publisher(Ko) :한국암반공학회
Journal Title :Tunnel and Underground Space
Journal Title(Ko) :터널과 지하공간
Volume : 31
No :6
Pages :469-479
Received Date : 2021-11-03
Revised Date : 2021-11-16
Accepted Date : 2021-11-22
DOI :https://doi.org/10.7474/TUS.2021.31.6.469

Tunnel and Underground Space ISSN:1225-1275(Print) 2287-1748(Online) 터널과 지하공간

All Issue