Full Deformation Diagrams for Non-Uniformly Compressed Concrete in Terms of Eccentrically Loading of Short Concrete Columns

ABSTRACT

The results of studies of deformation and fracture of uniaxially and eccentrically compressed heavy concrete with prismatic strength in the range f_c15=22,2…65,6 MPa under «soft» and «hard» loading conditions are presented. The analysis of its strength and elastoplastic properties is performed taking into account the influence of significant factors and their change with increasing load.

The experimental studies of the complete deformation diagrams of uniformly and non-uniformly compressed concrete with a change in the dimensions of the sample cross sections, the magnitude of the load eccentricity, the strength of the concrete, the loading regime are realized. The choice of the phenomenological dependence between stresses and deformations of a homogeneously and in homogeneously compressed concrete is substantiated.

Analytic expressions for the description of experimental complete deformation diagrams of uniaxially and eccentrically compressed concrete modeling the change in elastoplastic properties on the ascending and descending sections of the σ_c-ε_cх and σ_{c, е} – ε_{cх, е} diagrams under the action of a short-term static load are proposed.

The expressions for the complete diagrams of the variation of σ_с/f_c –(Е_c ^sek, v_c, K_D) is uniaxial and σ_{с, е} /f_{c, е} – (Е_{c, е} ^sek, v_{c, е}, K_{D, е}) of eccentrically compressed concrete reflecting the processes of development of destruction (nucleation and intensive growth of cracks) on submicro-, micro – and macrolevels of the structure of cement stone and concrete, which determine the accumulation and development of plastic pseudo-deformations with increasing load level.

The parameters of the nonlinear diagrams of the change in the secant modulus of deformations, the elasticity coefficient, and the intensity of the destructive development rate express the nonlinear character of the deformation diagrams of uniformly and in homogeneously compressed concrete as expressions characterizing the change in the elastoplastic properties that form part of the analytical dependences σ_c (ε_c).

Keywords: heavy concrete, short columns, uniaxial and eccentrically compression, loading mode, complete diagrams, secant modulus, coefficient of elasticity, coefficient development of destruction.

For citation: Sovgira Vasilisa, Sovgira Vasiliy Full Deformation Diagrams for Non-Uniformly Compressed Concrete in Terms of Eccentrically Loading of Short Concrete Columns. In: Contemporary Issues of Concrete and Reinforced Concrete: Collected Research Papers. Minsk. Institute BelNIIS. Vol. 9. 2017. pp. 436–454. https://doi.org/10.23746/2017-9-26

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