Poisson’s ratio of concrete is the ratio of transverse strain to longitudinal strain in concrete specimen subjected to axial loads. The longitudinal strain and vertical strain are produced due to concrete volume reduction under compression load. Volume reduction of concrete specimen is the result of crushing small aggregate sizes due to exerted loads. Poisson’s ratio of concrete is a constant for determining the stress and deflection properties of structures such as beams, plates, and shells
What is Poisson’s Ratio of concrete?
- The value of concrete Poisson’s ratio is possible to vary based on the type of specimen (dry, wet, or saturated), and loading conditions.
- Comparatively, Poisson’s ratio of concrete under static loads is lower than that of concrete upon which dynamic loads are applied.
- The concrete Poisson’s ratio under dynamic loads varies mostly between 0.20 to 0.25.
- By and large, it ranges from 0.1 for high strength concrete to 0.2 for low strength concrete.
- For design of concrete structures, the most common value of concrete Poisson’s ratio is taken as 0.2.
- It is recommended to practice great cautions to ensure that poisson’s ratio is compatible with values used for shear modulus of elasticity of concrete otherwise serious errors may be encountered.
- Poisson’s ratio of concrete is constant up to about 70% of strength.
- It can be computed from static modulus test.
- Poisson’s ratio can be determined dynamically from ultra sonic pulse velocity and from fundamental resonant frequency of longitudinal vibration of concrete beam.