Lateral Behavior of Concrete

Authors: Ali Khajeh Samani, Mario M. Attard

Abstract:

Lateral expansion is a factor defining the level of confinement in reinforced concrete columns. Therefore, predicting the lateral strain relationship with axial strain becomes an important issue. Measuring lateral strains in experiments is difficult and only few report experimental lateral strains. Among the existing analytical formulations, two recent models are compared with available test results in this paper with shortcomings highlighted. A new analytical model is proposed here for lateral strain axial strain relationship and is based on the supposition that the concrete behaves linear elastic in the early stages of loading and then nonlinear hardening up to the peak stress and then volumetric expansion. The proposal for the lateral strain axial strain relationship after the peak stress is mainly based on the hypothesis that the plastic lateral strain varies linearly with the plastic axial strain and it is shown that this is related to the lateral confinement level.

Keywords: Confined Concrete, Lateral Strain, Triaxial test, Postpeak behavior

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1081854

References:

[1] Cusson, D. and P. Paultre, Stress-strain model for confined highstrength concrete. Journal of Structural Engineering, 1995. 121: p. 468.
[2] Ahmad, S. and S. Shah, Stress-strain curves of concrete confined by spiral reinforcement. ACI Journal, 1982. 79(6): p. 484-490.
[3] Talaat, M. and K. Mosalam, Computational modeling of progressive collapse in reinforced concrete frame structures. 2007: University of California, Berkeley.
[4] Lokuge, W., J. Sanjayan, and S. Setunge, Stress-Strain Model for Laterally Confined Concrete. Journal of Materials in Civil Engineering, 2005. 17: p. 607.
[5] Attard, M. and S. Setunge, Stress-strain relationship of confined and unconfined concrete. ACI Materials Journal, 1996. 93(5).
[6] Imran, I. and S. Pantazopoulou, Experimental study of plain concrete under triaxial stress. ACI Materials Journal, 1996. 93(6): p. 589-601.
[7] Binici, B., An analytical model for stress-strain behavior of confined concrete. Engineering structures, 2005. 27(7): p. 1040-1051.
[8] Imran, I., Applications of non-associated plasticity in modeling the mechanical response of concrete. University of Toronto, 1994.
[9] Willam, K., B. Hurlbut, and S. Sture, Experimental and constitutive aspects of concrete failure. Finite Element Analysis of Reinforced Concrete Structures (Proceedings of the Seminar sponsored by the Japan Society for the Promotion of Science and the U.S. National Science Foundation), 1986: p. 226-254.
[10] Hurlbut, B., Experimental and computational investigation of strainsoftening in concrete. 1985, University of Colorado.
[11] Samani, A. and M. Attard, A Stress-Strain Model For Uniaxial Compression And Triaxially Confined Plain Concrete Incorporating Size Effect, in UNICIV Report R-457. 2010, The University of New South Wales, School of Civil and Environmental Engineering, Kensington,Sydney, Australia.
[12] Candappa, D., J. Sanjayan, and S. Setunge, Complete triaxial stress- strain curves of high-strength concrete. Journal of Materials in Civil Engineering, 2001. 13: p. 209.
[13] Jamet, P., A. Millard, and G. Nahas, Triaxial behaviour of microconcrete complete stress-strain curves for confining pressures ranging from 0 to 100 MPa. RILEM-CEB International conference concrete under multiaxial conditions, 1984. 1: p. 133-140.
[14] Smith, S., et al., Concrete Over the Top--Or, is there Life After Peak? ACI Materials Journal, 1989. 86(5).
[15] Lu, X. and C. Hsu, Stress-Strain Relations of High-Strength Concrete under Triaxial Compression. Journal of Materials in Civil Engineering, 2007. 19: p. 261.
[16] Newman, J., Concrete under complex stress, in Developments in Concrete Technology-I, F. Lydon, Editor. 1979. p. 151-219.