Journal: Volume 21, No. 3, 2016
Pages: 84 – 89
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Experimental and theoretical studies of stress-strain state of concrete at short-term axial compression based on its idealized structural schemes

М. Bitko, О. Kuznetsova, Volodymyr Boiko

Abstract

Concrete and reinforced concrete structures have gained the leading position in the construction industry over the past century. One of the characteristics of concrete is shown in its heterogeneity. This leads to the spread of its strength and elastic-plastic characteristics by 20-40%. In modern theory of concrete several trends are identified, such as: phenomenological, structural, statistical and destructive mechanic ones. Currently, much attention is paid to the development of structural theory. Calculation formulas are based on the strength and elastic-plastic characteristics of the concrete components, as well as their quantitative ratios and relative position in a unit of volume. Calculating is important and urgent as the valuation of physical and mechanical properties of the concrete components is much easier than that of concrete. Five idealized structural concrete schemes are considered for this purpose. The analysis has made it possible to identify that the spatial chess arrangement scheme of the ball shaped filler in the matrix most fully reflects how the concrete works. In this situation every single element is divided into three zones, where three parts of the ball of 1/8 each are placed in. This enables to obtain analytical dependence that could determine the elasticity modulus and its elastic-plastic characteristics. Theoretical conclusions are confirmed by experimental test data of three series of heavy concrete samples, sand concrete and cement stone. Numerical values of stresses in the concrete components, taking into account the redistribution effort, are given. These findings have theoretical novelty. They can be used to assess the internal stress-strain state and strength of concrete at a single uploading

Keywords

elasticity modulus, concrete, mortar, structural scheme, concrete components, filling aggregate, secant modulus of deformation

References

  1. Akhverdov, M N. (1970). Shrinkage and creep mechanism of concrete in light of modern concepts of rheology and solid-state physics. Concrete and Reinforced Concrete, (10), 21–23.
  2. Dmitriev, A.S. (1970). Influence of coarse aggregate on strength and deformability of high-strength concrete. In S. A. Mironov (Ed.), General Technology Issues and Acceleration of Concrete Hardening (pp. 58–63). Moscow: Stroyizdat.
  3. Gegasyan, S.G. (2001). Natural vibrations of a viscoelastic model of hereditary aging. Concrete and Reinforced Concrete, (5), 6–8.
  4. Gorokhov, E.V., Yugov, A.M., Veretennikov, V.N., et al. (2011). Consideration of systematic heterogeneity of heavy concrete properties. In Safety of Operation of Buildings and Structures (pp. 146–167). Moscow.
  5. Hansen, T. (1963). Creep and stress relaxation in concrete (Translated from English). Moscow: Gosstroiizdat. 124 p.
  6. Krylov, S.B., & Goncharov, E.E. (2013). Application of rheological models in concrete creep modeling. Industrial and Civil Construction, (2), 32–33.
  7. Makarenko, L.P., & Bytko, N.M. (1976). Experimental-statistical studies of stress-strain dependence in cement stone and concrete during long-term central compression under constant load of varying intensity. In A. S. Lychev (Ed.), Reliability Issues of Reinforced Concrete Structures (pp. 106–109). Kuibyshev.
  8. Makarenko, L.P., & Bytko, N.M. (1977). Experimental-statistical studies of stress-strain state of cement stone and concrete under two central compression modes with constant load increase and longitudinal deformations. In A. S. Lychev (Ed.), Reliability Issues of Reinforced Concrete Structures (pp. 89–92). Kuibyshev.
  9. Ovsyanko, V.M. (2003). Computer analysis of electronic models and rheological objects. Bulletin of Higher Educational Institutions. Construction, (4), 26–34.
  10. Zaitsev, Yu.V. (2003). Current state of concrete mechanics in Russia and abroad. Construction Materials, Equipment, Technologies of the XXI Century, (1), 18–19.

Suggested citation

Bitko, M., Kuznetsova, O., & Boiko, V. (2016). Experimental and theoretical studies of stress-strain state of concrete at short-term axial compression based on its idealized structural schemes. Bulletin of Cherkasy State Technological University, 21(3), 84-89.