Micromechanics model for static and dynamic strength of concrete under confinement

Abstract

The process of propagation, kinking of micro-cracks in concrete and the interaction among cracks as well as the induced failure were analyzed using the model that describes the wing type crack from the point of view of micromechanics. The pseudo-force method is applied to calculate the compressive strength factor of kinky propagated crack taking into account the effect of interaction among cracks. On the assumption that the micro fracture toughness of concrete does not vary with stain rate, the static and dynamic strength of concrete under different confinements can be calculated. The comparison of calculation result with experimental data indicates that a good agreement is achieved which implies that the model can be used to explain the rate-dependent properties of concrete in multi-axial stress state.

References

1. Gran J K, Florence A L, Colton J D . Dynamic triaxial test of high-strength concrete. Journal of Engineering Mechanics, 1989, 115(5): 891–904
2. Song Yupu, Lü Peiyin, Hou Jingpeng . Concrete splitting tensile strength and failure criterionfor different loading rate and lateral stress. Shuili Xuebao, 2002, 33(3): 1–5 (in Chinese)
3. Yan Dongming, Lin Gao, Liu Junyu, et al.. Dynamic biaxial compressive strength and fracturepattern of concrete with constant confining pressure. Shuili Xuebao, 37(2): 200–204 (in Chinese)
4. Guo Zhenghai . Strength and Deformation of Concrete: Test Basis and ConstitutiveRelation. Beijing: Tsinghua University Press, 1997 (in Chinese)
5. Park H, Kim J Y . Plasticity model using multiplefailure criteria for concrete in compression. International Journal of Solids & Structures. 2005, 42: 2303–2322. doi:10.1016/j.ijsolstr.2004.09.029
6. Richart F E, Brandtzaeg A, Brown R L . A study of the failure of concrete under combined compressivestresses. Engineering Experiment BulletinNo. 185, Univ. of Illinois, Urbana, 1928
7. Imran I, Pantazopoulou S J . Plasticity model for concreteunder triaxial compression. Journal ofEngineering Mechanics, ASCE, 2001, 127(3): 281–290. doi:10.1061/(ASCE)0733-9399(2001)127:3(281)
8. Yu Maoqing . Concrete Strength Theory and Application. Beijing: Higher Education Press, 2002 (in Chinese)
9. Horri H, Nemat Nasser S . Compression induced microcrackgrowth in brittle solids: axial splitting and shear failure. Journal of Geophysics Research, 1985, 90: 3105–3125. doi:10.1029/JB090iB04p03105
10. Ashby M F, Hallam S D . The failure of brittle solidscontaining small cracks under compressive states. Acta Metallica, 1986, 34: 497–510. doi:10.1016/0001-6160(86)90086-6
11. Deng H, Nemat Nasser S . Microcrack interaction andshear fault failure. International Journalof Damage Mechanics, 1994, (3): 3–37
12. Zheng D, Li Q B, Wang L B, A microscopic approach to rate effect on compressivestrength of concrete. Engineering FractureMechanics, 2005, 72(15): 2316–2327. doi:10.1016/j.engfracmech.2005.01.012