Creep and Shrinkage Modeling of Concrete Using Solidification Theory

A new semiempirical creep and shrinkage model is proposed wherein basic creep, drying creep, and drying shrinkage are all considered to age according to solidification theory. Applied to basic creep, this proposed formulation results in a closed-form expression for the compliance function when using two different volume growth functions: one approximating typical strength gain of concrete, and a second matching the slower aging from the B4 model. Drying shrinkage and drying creep, which is treated as a load-induced shrinkage, are combined into total drying strains while still accounting for aging through solidification. The model for drying strains satisfies all asymptotic conditions required by diffusion analysis. Approximations appropriate for design purposes are proposed for the drying strains, and the associated creep and shrinkage strain rates also are provided. The proposed model was compared with measured experimental data and contrasted with the B4 model.