A new dynamic testing method for elastic, shear modulus and Poisson’s ratio of concrete

Abstract

In this work, an energy-based method was used to derive the correlation between concrete shear modulus and torsional frequency of free slab based on first-order torsional mode shape of free slab. The relationship between dynamic elastic modulus of concrete and first-order bending frequency of free slab was also obtained. According to stress and strain analysis of first-order bending mode of concrete cantilever slab and the physical relationship between stress and strain under state of plane stress, the dynamic method for testing Poisson’s ratio μ of concrete was proposed. For the concrete with a compressive strength of 22.6MPa, a transient excitation method was used to determine its dynamic elastic modulus E and shear modulus G; and a steady-state sine excitation method was used to determine its dynamic Poisson’s ratio μ. The results of dynamic test showed that the ratio of shear modulus G and elastic modulus E is 0.403; elastic modulus E, shear modulus G and Poisson’s ratio μ, follow the relationship given by E=2G(1+μ).