Viscoelastic properties and drying stress extracted from concrete ring tests

Passive restrained concrete ring experiments provide enough information to extract useful aging viscoelastic constitutive properties when combined with free drying shrinkage and mass loss experiments. In this paper, analytical techniques are described for deriving a closed-form solution to extract the viscoelastic Young's modulus from solidifying concrete in a restrained concrete ring test. Using limit theorems, approximate closed-form solutions are derived for the non-uniform internal relative humidity (RH), free drying shrinkage, and tangential stress gradients. An example problem demonstrates the utility of the derived solutions and illustrates the effect that viscoelastic relaxation and solidification have on the tangential stress profile in the restrained, drying concrete ring. Both viscoelastic and solidification effects have a significant impact on the predicted stress profile.