Failure Mode and Constitutive Model of Plain High-Strength High-Performance Concrete under Biaxial Compression after Exposure to High Temperatures
An orthotropic constitutive relationship with temperature parameters for plain high-strength high-performance concrete (HSHPC) under biaxial compression is developed. It is based on the experiments performed for characterizing the strength and deformation behavior at two strength levels of HSHPC at 7 different stress ratios including α = σ2: σ3 = 0.00: −1, −0.20: −1, −0.30: −1, −0.40: −1, −0.50: −1, −0.75: −1, −1.00: −1, after the exposure to normal and high temperatures of 20, 200, 300, 400, 500 and 600°C, and using a large static-dynamic true triaxial machine. The biaxial tests were performed on 100 mm × 100 mm × 100 mm cubic specimens, and friction-reducing pads were used consisting of three layers of plastic membrane with glycerine in-between for the compressive loading plane. Based on the experimental results, failure modes of HSHPC specimens were described. The principal static compressive strengths, strains at the peak stress and stress-strain curves were measured; and the influence of the temperature and stress ratios on them was also analyzed. The experimental results showed that the uniaxial compressive strength of plain HSHPC after exposure to high temperatures does not decrease dramatically with the increase of temperature. The ratio of the biaxial to its uniaxial compressive strength depends on the stress ratios and brittleness-stiffness of HSHPC after exposure to different temperature levels. Comparison of the stress-strain results obtained from the theoretical model and the experimental data indicates good agreement.
Key wordshigh-strength high-performance concrete (HSHPC) high temperatures uniaxial and biaxial compressive strength failure criterion stress-strain relationship
Unable to display preview. Download preview PDF.
- Kupfer, H., Behavior of concrete under biaxial stresses. ACI Journal, 1969, 66(8): 656–666.Google Scholar
- Luo, X., Sun, W. and Chan, Y.N., Residual compressive strength and microstructure of high performance concrete after exposure to high temperature. Materials and Structures/Materiaux et Constructions, 2000, 33(6): 294–298.Google Scholar
- Chan, S.Y.N., Peng, G.F. and Chan, J.K.W., Comparison between high strength concrete and normal strength concrete subjected to high temperature. Materials and Structures/Matdriaux et Constructions, 1996, 29(12): 616–619.Google Scholar
- The High-strength High-performance Concrete Committee of China Civil Engineering Society, Guide for Structural Design and Construction of High-strength Concrete. Beijing: China Architecture and Building Press, 2001 (in Chinese).Google Scholar
- Guo, Z.H. and Shi, X.D., Reinforced Concrete Theory and Analyse. Beijing: TsingHua University Press, 2003 (in Chinese).Google Scholar
- Guo, Z.H., Guo, Y.T., Xu, Y., Ye, X.G. and Li, W.Z., Nonlinear elastic orthotropic constitutive model for concrete. Journal of Tsinghua university (Sci & Tech), 1997, 37(6): 78–81.Google Scholar
- Qin, L.K., Song, Y.P., Zhang, Z. and Yu, C.J., The research on strength and deformation of plain concrete under biaxial compression after high temperatures. Journal of Dalian University of Technology, 2005, 45(1): 113–117 (in Chinese).Google Scholar