Abstract
A local fracture energy model originally proposed to explain the influence of fracture process zone (FPZ) on fracture energy of cementitious materials is further developed in this study. By assuming a bilinear distribution for the fracture energy distribution, the ligament-dependent fracture energyG f is obtained. The analytical expression ofG f contains two important prameters: the intrinsic size-independent fracture energyG F and a reference ligament sizea *l which determines the intersection of the two linear fracture energy functions. It is shown that the ligament-dependentG f approaches the size-independentG F asymptotically. As a result,G F can be determined from the ligament-dependentG f results. It is also found that while the reference ligament sizea *l is influenced by the specimen geometry, size and loading conditions, the derived fracture energyG F is virtually constant. The present local fracture energy distribution model is also discussed and compared with the original local fracture energy model.
Résumé
Cette étude présente un développement plus approfondi d'un modèle de l'énergie locale de rupture, originairement proposé pour expliquer l'effet de la taille de la zone d'endommagement sur l'énergie de rupture des matériaux à base de ciment. En supposant une distribution bilinéaire de l'énergie locale de rupture, on peut obtenir l'énergie de rupture Gf dépendante de la longueur du ligament. L'expression analytique de l'énergie de rupture GF contient deux paramètres importants: l'énergie de rupture GF, indépendante de la taille, et une valeur de référence de la longueur du ligament, a *l , qui détermine l'intersection de la distribution bilinéaire de l'énergie locale de rupture. On montre que l'énergie de rupture dépendante du ligament Gf tend asymptotiquement vers la valeur de l'énergie de rupture non-dépendante de la taille, GF. Ainsi, GF peut être déduite de l'énergie dépendante du ligament, Gf. On a aussi remarqué que l'énergie de rupture GF, ainsi déduite, demeure virtuellement constante bien que la logueur de référence du ligament, a *l , puisse être influencée par la géométrie et la taille de l'éprouvette et les conditions de sollicitations. Ce modèle de distribution d'énergie locale de rupture est discuté en détail dans cette contribution et est comparé avec le modèle original de l'énergie locale de rupture.
Similar content being viewed by others
References
Kaplan, M. F., ‘Crak propagation and the fracture of concrete’,ACI Journal 58 (1961) 591–610.
Walsh, P. F., ‘Fracture of plain concrete’,Indian Concr. J. 46 (1972).
Higgins, D. D. and Bailey, J. E., ‘Fracture measurements on cement paste’,J. Mater. Sci. 11 (1976) 1995–2003.
Bažant, Z. P., ‘Size effect in blunt fracture: concrete, rock, metal’,J. Eng. Mech., ASCE 110 [4] (1984) 518–535.
Bažant, Z. P. and Pfeiffer, P. A., ‘Determination of fracture energy from size effect and brittleness number’,ACI Mater. J. 84 (1987) 463–480.
Mindess, S., ‘The effect of specimen size on the fracture energy of concrete’,Cem. Concr. Res. 14 (1984) 431–436.
Nallathambi, P., Karihaloo, B. L. and Heaton, B. S., ‘Effect of specimen and crack sizes, water/cement ratio and coarse aggregate texture upon fracture toughness of concrete’,Mag. Concr. Res. 36 (129) (1984) 227–236.
Nallathambi, P., Karihaloo, B. L. and Heaton, B. S., ‘Various size effects in fracture of concrete’,Cem. Concr. Res.,15 (1985) 117–126.
Hillerborg, A., ‘Results of three comparative test series for determining the fracture energyG F of concrete’,Mater. Struct. 18 (1985) 33–39.
Hu, X. Z., ‘Fracture Process Zone and Strain Softening in Cementitious Materials’, ETH Building Materials Reports No. 1, ETH Switzerland, 1990 (Aedificatio Publishers, Freiburg, 1995).
Hu, X. Z. and Wittmann, F. H., ‘Fracture energy and fracture process zone’,Mater. Struct. 25 (1992) 319–326.
Wittmann, F. H., ‘Fracture process zone and fracture energy’, in ‘Fracture Mechanics of Concrete Structures’, Proc. FRAMCOS-1, Breackenridge, Colorado, USA, 1–5 June 1992, ed. Z. P. Bažant (Elsevier Applied Science) 391–403.
Wittmann, X. and Zhong, H., ‘On some experiments to study the influence of size on strength and fracture energy of concrete’, ETH Building Materials Reports No. 2, ETH Switzerland, 1994 (Aedificatio Publishers, Freiburg, 1996).
Trunk, B., ‘Influence of structural size on the fracture energy of concrete’, ETH Building Materials Reports No 11, ETH Switzerland, 2000 (Aedificatio Publishers, Freiburg, 2000) (only available in German).
Mindess, S. and Nadeau, J. S. ‘Effect of noth onK IC for mortar and concrete’,Cem. Concr. Res. 6, (4) (1976) 529–534.
Tian, M.-L., Huang, S.-M., Liu, E.-X., Wu, L.-Y., Long, K.-Q. and Yang, S.-M., ‘Fracture toughness of concrete’, in ‘Fracture Toughness and Fracture Energy of Concrete’, Proc. Int. Conf. on Fracture Mechanics of Concrete, Lausanne, Switzerland, Oct. 1–3, 1985, Ed. F. H. Wittmann (Elsevier Science Publishers, 1986) 299–306.
van Vliet, M. R. A. and van Mier, J. G. M., ‘Experimental investigation of size effect in concrete under uniaxial tension’, in ‘Fracture Mechanics of Concrete Structures’, Proc. FRAMCOS-3, Gifu, Japan, Oct. 12–16, 1998, Ed. H. Mihashi and K. Rokugo (Aedificatio Publishers, Freburg, 1998) 1923–1936.
Hillerborg, A., Modeer, M. and Petersson, P. E., ‘Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements’,Cem. Concr. Res. 6 (1976) 773–782.
Petersson, P.-E., ‘Crack growth and development of fracture zones in plain concrete and similar structures’, Report TVBM-1006. (Division of Building Materials, Lund Institute of Technology, Sweden, 1981).
Hillerborg, A., ‘Analysis of one single crack’, in ‘Fracture Mechanics of Concrete’, ed. F. H. Wittmann (Elsvier, Amsterdam, 1983) 223–249.
Carpiteri, A., Chiaia, B. and Ferro, G., ‘Size effects on nominal tensile strengh of concrete structures: multifractality of material ligaments and dimensional transition from order to disorder’,Mater. Struct. 28 (1995) 311–317.
Carpinteri, A. and Chiaia, B., ‘Multifractal scaling law for the fracture energy variation of concrete structures’, in ‘Fracture Mechanics of Concrete Structures’, Proc. FRAMCOS-2, Zurich, Switzerland, July 25–28, 1995, Ed. F. H. Wittmann (Aedificatio Publishers, 1995), 581–596.
Hu, X. Z., ‘Toughness measurements from crack close to free edge’,Inter. J. Frac. 86 (1997) L63-L68.
Hu, X. Z., ‘Size effects in toughness induced by crack close to free edge’, in ‘Fracture Mechanics of Concrete Structures’, Proceedings of FRAMCOS-3, Gifu, Japan, Oct. 12–16, 1998, Ed. H. Mihashi and K. Rokugo (Aedificatio Publishers, Freiburg, 1998) 2011–2020.
Hu, X. Z., ‘An asymptotic approach to size effect on fracture toughness and energy’, Proc. of Inter. Workshop on Fracture Mechanics and Advanced Engineering Materials, Dec. 8–10, 1999, Sydney, ed. L. Ye and Y.W. Mai, 76–83.
Hu, X. Z. and Wittmann, F. H., ‘Size effect on toughness induced by crack close to free surface’,Eng. Fract. Mech.,65 (2000) 209–211.
Hu, X. Z., ‘An asymptotic approach to size effect on fracture toughness and fracture energy of composites’,Eng. Fract. Mech. 69 (2002) 555–564.
Duan, K., Hu, X. Z. and Wittmann, F. H., ‘Size effect on fracture resistance and fracture energy of concrete’, accepted byMater. Struct.
RILEM TC-50 FMC, ‘Determination of the fracture energy of mortar and concrete by means of three-point bend tests on notched beans’,Mater. Struct.,18 (1985) 287–290.
Dowling, N. E., ‘Mechanical Behavior of Materials’, 2nd Edn. (Prentice Hall International, Inc. 1999).
Bažant, Z. P. and Lin, F.-B., ‘Nonocal smeared cracking model for concrete fracture’,J. Struct. Eng., ASCE 114 (1988) 2493–2510.
Otsuka, K., Date, H. and Kurita, T., ‘Fracture process zone in concrete tension specimens by X-ray and AE techniques’, in ‘Fracture Mechanics of Concrete Structures’, Proc. FRAMCOS-3, Gifu, Japan, Oct. 12–16, 1998, Ed. H. Mihashi and K. Rokugo (Aedificatio Publishers, Preiburg, 1998) 3–16.
Brühwiler, E., ‘Fracture mechanics of dam concrete subjected to quasi-static and seismic loading conditions’, PhD Thesis, Laboratory for Building Materials, ETH, Lausanne (in German).
Brühwiler, E. and Wittmann, F. H., ‘The wedge splitting test, a new method of performing stable fracture mechanics tests’,Eng. Fract. Mech.,35 (1990) 117–125.
Cotterell, B. and Mai, Y.-W., ‘Fracture Mechanics of Cementitious Materials’ (Blackie Academic & Professional, 1996).
Duan, K., Hu, X. Z. and Wittmann, F. H., ‘Thickness effect on fracture energy of cementitious materials’, submitted toCem. Concr. Res.
van Mier, J. G. M., ‘Crack face bridging in normal, high strength and lytag concrete’, in ‘Fracture processes in Concrete, Rock and Ceramics’, Proc. Int. RILEM/ESIS Conf., Noordwijk, The Netherlands, June 1991. Eds. J. G. M. van Mier, J. G. Rots and A. Bakker (E & FN Spon, 1991) 27–40.
Author information
Authors and Affiliations
Additional information
Editorial Note Prof. Folker H. Wittmann is a RILEM Senior Member.
Rights and permissions
About this article
Cite this article
Duan, K., Hu, X.Z. & Wittmann, F.H. Explanation of size effect in concrete fracture using non-uniform energy distribution. Mat. Struct. 35, 326–331 (2002). https://doi.org/10.1007/BF02483151
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02483151