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Experimental and numerical simulating of the crack separation on the tensile strength of concrete

  • Sarfarazi, Vahab (Department of Mining Engineering, Hamedan University of Technology) ;
  • Haeri, Hadi (Young Researchers and Elite Club, Bafgh Branch, Islamic Azad University) ;
  • Shemirani, Alireza Bagher (Department of Civil Engineering, Sadra Institute of Higher Education) ;
  • Zhu, Zheming (College of Architecture and Environment, Sichuan University) ;
  • Marji, Mohammad Fatehi (Mine Exploitation Engineering Department, Faculty of Mining and Metallurgy, Institution of Engineering, Yazd University)
  • 투고 : 2018.01.30
  • 심사 : 2018.03.09
  • 발행 : 2018.06.10

초록

Effects of crack separation, bridge area, on the tensile behaviour of concrete are studied experimentally and numerically through the Brazilian tensile test. The physical data obtained from the Brazilian tests are used to calibrate the two-dimensional particle flow code based on discrete element method (DEM). Then some specially designed Brazilian disc specimens containing two parallel cracks are used to perform the physical tests in the laboratory and numerically simulated to make the suitable numerical models to be tested. The experimental and numerical results of the Brazilian disc specimens are compared to conclude the validity and applicability of these models used in this research. Validation of the simulated models can be easily checked with the results of Brazilian tests performed on non-persistent cracked physical models. The Brazilian discs used in this work have a diameter of 54 mm and contain two parallel centred cracks ($90^{\circ}$ to the horizontal) loaded indirectly under the compressive line loading. The lengths of cracks are considered as; 10 mm, 20 mm, 30 mm and 40 mm, respectively. The visually observed failure process gained through numerical Brazilian tests are found to be very similar to those obtained through the experimental tests. The fracture patterns demonstrated by DEM simulations are mostly affected by the crack separation but the tensile strength of bridge area is related to the fracture pattern and failure mechanism of the testing samples. It has also been shown that when the crack lengths are less than 30 mm, the tensile cracks may initiate from the cracks tips and propagate parallel to loading direction till coalesce with the other cracks tips while when the cracks lengths are more than 30 mm, these tensile cracks may propagate through the intact concrete itself rather than that of the bridge area.

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참고문헌

  1. Al-Shayea, N.A. (2005), "Crack propagation trajectories for rocks under mixed mo de I-II fracture", Eng. Geol., 81(1), 84-97. https://doi.org/10.1016/j.enggeo.2005.07.013
  2. Al-Shayea, N.A., Khan, K. and Abduljauwad, S.N. (2000), "Effects of confining pressure and temperature on mixed-mode (I-II) fracture toughness of a limes tone roc k formation", Int. J. Rock Mech. Rock Eng., 37(4), 629-643. https://doi.org/10.1016/S1365-1609(00)00003-4
  3. Atkinson, C., Smelser, R.E. and Sanchez, J. (1982), "Combined mode fracture via the cracked Brazilian disk", Int. J. Fract., 18(4), 279-291. https://doi.org/10.1007/BF00015688
  4. Awaji, H. and Sato, S. (1978), "Combined mode fracture toughness measurement by the disk test", J. Eng. Mater. Technol., 100(2), 175-182. https://doi.org/10.1115/1.3443468
  5. Ayatollahi, M.R. and Aliha, M.R.M. (2008), "On the use of Brazilian disc specimen for calculating mixed mode I-II fracture toughness of rock materials", Eng. Fract. Mech., 75(16), 4631-4641. https://doi.org/10.1016/j.engfracmech.2008.06.018
  6. Ayatollahi, M.R. and Sistaninia, M. (2011), "Mode II fracture study of rocks using Brazilian disk specimens", Int. J. Rock Mech. Min. Sci., 48(5), 819-826. https://doi.org/10.1016/j.ijrmms.2011.04.017
  7. Bagher Shemirani, A., Haeri, H., Sarfarazi, V. and Hedayat, A. (2017), "A review paper about experimental investigations on failure behaviour of non-persistent joint", Geomech. Eng., 13(4), 535-570.
  8. Bagher Shemirani, A., Sarfarazi, V., Haeri, H., Marji, M. and Hosseini, S. (2018), "A discrete element simulation of a punchthrough shear to investigate the confining pressure effects on the shear behaviour of concrete cracks", Comput. Concrete, 21(2), 189-197. https://doi.org/10.12989/CAC.2018.21.2.189
  9. Bahaaddini, M., Sharrock, G. and Hebblewhite, B.K. (2013), "Numerical investigation of the effect of joint geometrical parameters on the mechanical properties of a non-persistent jointed rock mass under uniaxial compression", Comput. Geotech., 49, 206-225. https://doi.org/10.1016/j.compgeo.2012.10.012
  10. Bobet, A. (2000), "The initiation of secondary cracks in compression", Eng. Fract. Mech., 66(2), 187-219. https://doi.org/10.1016/S0013-7944(00)00009-6
  11. Bobet, A. and Einstein, H.H. (1998), "Fracture coalescence in rock-type materials under uniaxial and biaxial compression", Int. J. Rock Mech. Min. Sci., 35(7), 863-888. https://doi.org/10.1016/S0148-9062(98)00005-9
  12. Cho, N. (2008), "Discrete element modeling of rock: pre-peak fracturing and dilation", Ph.D. Dissertation, University of Alberta, Canada.
  13. Cho, N., Martin, C.D. and Sego, D.C. (2007), "A clumped particle model for rock", Int. J. Rock Mech. Min. Sci., 44(7), 997-1010. https://doi.org/10.1016/j.ijrmms.2007.02.002
  14. Cundall, P.A. (1971), "A computer model for simulating progressive large scale movements in blocky rock systems", Proceedings of the ISRM Symposium.
  15. Cundall, P.A. (2000), "A discontinuous future for numerical modelling in geomechanics", Geotech. Eng., 149(1), 41-47.
  16. Diederichs, M.S. (2000), "Instability of hard rock masses: The role of tensile damage and relaxation", Ph.D. Dissertation, University of Waterloo, Canada.
  17. Ghazvinian, A., Nejati, H.R., Sarfarazi, V. and Hadei, M.R. (2013), "Mixed mode crack propagation in low brittle rock-like materials", Arab J. Geosci., 6(11), 4435-4444. https://doi.org/10.1007/s12517-012-0681-8
  18. Haeri, H. (2015), "Influence of the inclined edge notches on the shear-fracture behavior in edge-notched beam specimens", Comput. Concrete, 16(4), 605-623. https://doi.org/10.12989/cac.2015.16.4.605
  19. Haeri, H., Khaloo, A. and Marji, M.F. (2015), "Experimental and numerical simulation of the microcrack coalescence mechanism in rock-like materials", Strength Mater., 47(5), 740-754. https://doi.org/10.1007/s11223-015-9711-6
  20. Haeri, H., Sarfarazi, V. and Hedayat, A. (2016), "Suggesting a new testing device for determination of tensile strength of concrete", Struct. Eng. Mech., 60(6), 939-952. https://doi.org/10.12989/sem.2016.60.6.939
  21. Hazzard, J.F. and Young, R.P. (2000), "Simulating acoustic emissions in bonded-particle models of rock", Int. J. Rock Mech. Min. Sci., 37(5), 867-872. https://doi.org/10.1016/S1365-1609(00)00017-4
  22. Ingraffea, A.R. and Heuze, F.E. (1980), "Finite element models for rock fracture mechanics", Int. J. Numer. Anal. Meth. Geomech., 4(1), 25-43. https://doi.org/10.1002/nag.1610040103
  23. Itasca Consulting Group (2004), PFC2D (Particle Flow Code in 2 Dimensions) Version 3.1.
  24. Jiefan, H., Ganglin, C., Yonghong, Z. and Ren, W. (1990), "An experimental study of the strain field development prior to failure of a marble plate under compression", Tectonophys., 175(1-3), 269-284. https://doi.org/10.1016/0040-1951(90)90142-U
  25. Khan, K. and Al-Shayea, N.A. (2000), "Effects of specimen geometry and testing method on mixed-mode I-II fracture toughness of a limestone rock from Saudi Arabia", Rock Mech. Rock Eng., 33(3), 179-206. https://doi.org/10.1007/s006030070006
  26. Krishnan, G.R., Zhao, X.L., Zaman, M. and Rogiers, J.C. (1998), "Fracture toughness of a soft sandstone", Int. J. Fract. Mech., 35(6), 195-218.
  27. Lambert, C. and Coll, C. (2013), "Discrete modeling of rock joints with a smooth-joint contact model", J. Rock Mech. Geotech. Eng., 6(1), 1-12.
  28. Li, J.Y., Zhou, H., Zhu, W. and Li, S. (2016), "Experimental and numerical investigations on the shear behavior of a jointed rock mass", Geosci. J., 20(3), 371-379. https://doi.org/10.1007/s12303-015-0052-z
  29. Li, S., Wang, H., Li, Y., Li, Q., Zhang, B. and Zhu, H. (2016), "A new mini-grating absolute displacement measuring system for static and dynamic geomechanical model tests", Measure., 82, 421-431.
  30. Li, Y., Zhou, H., Zhu, W., Li, S. and Liu, J., (2015), "Numerical study on crack propagation in brittle jointed rock mass influenced by fracture water pressure", Mater., 8(6), 3364-3376. https://doi.org/10.3390/ma8063364
  31. Manouchehrian, A., Sharifzadeh, M., Marji, M.F. and Gholamnejad, J. (2014), "A bonded particle model for analysis of the flaw orientation effect on crack propagation mechanism in brittle materials under compression", Arch. Civil Mech. Eng., 14(1), 40-52. https://doi.org/10.1016/j.acme.2013.05.008
  32. Mughieda, O. and Alzoubi, K.A. (2004), "Fracture mechanisms of offset rock joints-a laboratory investigation", Geotech. Geol. Eng., 22(4), 545-562. https://doi.org/10.1023/B:GEGE.0000047045.89857.06
  33. Park, C.H. (2008), "Coalescence of frictional fractures in rock materials", Ph.D. Dissertation, Purdue University West Lafayette, Indiana, U.S.A.
  34. Petit, J. and Barquins, M. (1988), "Can natural faults propagate under mode II conditions?", Tecton., 7(6), 1243-1256. https://doi.org/10.1029/TC007i006p01243
  35. Potyondy, D.O. and Cundall, P.A. (2004), "A bonded-particle model for rock", Int. J. Rock Mech. Min. Sci., 41(8), 1329-1364. https://doi.org/10.1016/j.ijrmms.2004.09.011
  36. Reyes, O. and Einstein, H.H. (1991), "Failure mechanism of fractured rock-a fracture coalescence model", Proceedings of the 7th International Congress of Rock Mechanics.
  37. Sanchez, J. (1979), "Application of the disk test to mode-I-II fracture toughness analysis", M.Sc. Dissertation, University of Pittsburgh, Pittsburgh, U.S.A.
  38. Sarfarazi, V., Ghazvinian, A., Schubert, W., Blumel, M. and Nejati, H.R. (2014), "Numerical simulation of the process of fracture of echelon rock joints, rock mechanics and rock engineering", 47(4), 1355-1371. https://doi.org/10.1007/s00603-013-0450-3
  39. Sarfarazi, V., Haeri, H. and Bagher Shemirani, A. (2017a), "Direct and indirect methods for determination of mode I fracture toughness using PFC2D", Comput. Concrete, 20(1), 39-47. https://doi.org/10.12989/CAC.2017.20.1.039
  40. Sarfarazi, V., Haeri, H., Bagher Shemirani, A. and Zhu, Z. (2017b), "The effect of compression load and rock bridge geometry on the shear mechanism of weak plane", Geomech. Eng., 13(3), 57-63.
  41. Sarfarazi, V., Haeri, H., Bagher Shemirani, A., Hedayat, A. and Hosseini, S. (2017c), "Investigation of ratio of TBM disc spacing to penetration depth in rocks with different tensile strengths using PFC2D", Comput. Concrete, 20(4), 429-437.
  42. Scavia, C. and Castelli, M. (1998), "Studio della propagazione per trazione indotta di sistemi di fratture in roccia", Rivista Italiana di Geotecnica, anno XXXII, 48-62.
  43. Shaowei, H., Aiqing, X., Xin, H. and Yangyang, Y. (2016), "Study on fracture characteristics of reinforced concrete wedge splitting tests", Comput. Concrete, 18(3), 337-354. https://doi.org/10.12989/cac.2016.18.3.337
  44. Shemirani, A., Naghdabadi, R. and Ashrafi, M. (2016), "Experimental and numerical study on choosing proper pulse shapers for testing concrete specimens by split Hopkinson pressure bar apparatus", Constr. Build. Mater., 125, 326-336. https://doi.org/10.1016/j.conbuildmat.2016.08.045
  45. Shen, B. and Stephansson, O. (1993), "Large-scale permeability tensor of rocks from induced microseismicity", Int. J. Rock Mech. Min. Sci. Geomech. Abstr., 30, 861-867. https://doi.org/10.1016/0148-9062(93)90037-E
  46. Shen, B., Stephansson, O., Einstein, H.H. and Ghahreman, B. (1995), "Large-scale permeability tensor of rocks from induced micro-seismicity", J. Geophys. Res., 100, 5975-5990. https://doi.org/10.1029/95JB00040
  47. Shetty, D.K., Rosenfield, A.R. and Duckworth, W.H. (1986), "Mixed mode fracture of ceramic in diametrical compression", J. Am. Ceram. Soc., 69(6), 437-443. https://doi.org/10.1111/j.1151-2916.1986.tb07441.x
  48. Wang, Q.Z. (2010), "Formula for calculating the critical stress intensity factor in rock fracture toughness tests using cracked chevron notched Brazilian disc (CCNBD) specimens", Int. J. Rock Mech. Min. Sci., 47(6), 1006-1011. https://doi.org/10.1016/j.ijrmms.2010.05.005
  49. Wang, Q.Z., Feng, F., Ni, M. and Gou, X.P. (2011), "Measurement of mode I and mode II rock dynamic fracture toughness with cracked straight through flattened Brazilian disc impacted by split Hopkinson pressure bar", Eng. Fract. Mech., 78(12), 2455-2469. https://doi.org/10.1016/j.engfracmech.2011.06.004
  50. Wang, Q.Z., Gou, X.P. and Fan, H. (2012), "The minimum dimensionless stress intensity factor and its upper bound for CCNBD fracture toughness specimen analyzed with straight through crack assumption", Eng. Fract. Mech., 82, 1-8. https://doi.org/10.1016/j.engfracmech.2011.11.001
  51. Wang, X., Zhu, Z., Wang, M., Ying, P., Zhou, L. and Dong, Y. (2017), "Study of rock dynamic fracture toughness by using VB-SCSC specimens under medium-low speed impacts", Eng. Fract. Mech., 181, 52-64. https://doi.org/10.1016/j.engfracmech.2017.06.024
  52. Wei, M.D., Dai, F., Xu, N.W., Xu, Y. and Xia, K. (2015), "Threedimensional numerical evaluation of the progressive fracture mechanism of cracked chevron notched semi-circular bend rock specimens", Eng. Fract. Mech., 134, 286-303. https://doi.org/10.1016/j.engfracmech.2014.11.012
  53. Wong, R.H.C. and Chau, K.T. (1998), "Crack coalescence in a rock-like material containing two cracks", Int. J. Rock Mech. Min. Sci., 35(2), 147-164. https://doi.org/10.1016/S0148-9062(97)00303-3
  54. Wong, R.H.C., Tang, C.A., Chau, K.T. and Lin, P. (2002), "Splitting failure in brittle rocks containing pre-existing flaws under uniaxial compression", Eng. Fract. Mech., 69(1), 853-871.
  55. Yang, S.Q. (2015), "An experimental study on fracture coalescence characteristics of brittle sandstone specimens combined various flaws", Geomech. Eng., 8(4), 541-557. https://doi.org/10.12989/gae.2015.8.4.541