Home Concrete Modulus of Elasticity and Poisson’s ratio of concrete (definition and values)

Modulus of Elasticity and Poisson’s ratio of concrete (definition and values)

The Elastic modulus of concrete is the coefficient of proportionality between the normal stress and the corresponding relative longitudinal elastic instantaneous deformation at σ1 = 0.3Rpr with axial compression of the samples. (GOST 24452-80 Concretes Russian building standard, Rpr — prismatic strength of concrete) The value of the initial modulus of Elasticity of heavy concrete under compression and tension is given in SP 63.13330.2012 Concrete and reinforced concrete structures. This regulatory document is valid in Russia. In accordance with table 6.11 p. 6.1.15 SP 63.13330.2012 for heavy concrete:

Concrete class The value of the modulus of Elasticity of concrete in compression,  Eb, MPa
B10 19000 MPa
B12,5 21500 MPa
B15 24000 MPa
B20 27500 MPa
B25 30000 MPa
B30 32500 MPa
B35 34500 MPa

The elastic modulus of concrete with prolonged load is determined by the formula:

Eb,t = Eb / (1 + φb,cr)

φb,cr — creep coefficient of concrete, taken according to table 6.12 p. 6.1.16

In accordance with table 6.12 p. 6.1.16 SP 63.13330.2012 for heavy concrete B10-B35:

Relative humidity of the ambient air, % В10 В15 В20 В25 В30 В35
Above 75 2,8 2,4 2,0 1,8 1,6 1,5
40-75 3,9 3,4 2,8 2,5 2,3 2,1
Below 40 5,6 4,8 4,0 3,6 3,2 3,0
Note: The relative humidity of the ambient air is taken according to SP 131.13330 (Russian building standard) as the average monthly relative humidity of the warmest month for the construction area. The Poisson’s ratio of concrete is allowed to take 0.2 (p. 6.1.17 SP 63.13330.2012 (Russian building standard), in the absence of experimental data).