Drying creep of concrete: constitutive model and new experiments separating its mechanisms

A new experimental method which allows the direct separation of the components of drying creep due to micro cracking and stress-induced shrinkage is developed, demonstrated and validated. The hasic idea is to compare the curL'CIture creep of heams suhjected to the same hending moment hut rery different axial forces. The results confirm that drying creep has two different sources: microcracking and stress-induced shrinkage. The latter increases continuously, whereas the former .first increases and then decreases. The test results are .fitted usiny a finite element model. The results validate the present model.fc)r drying creep. The microcrackiny is described by an established model, and the free (unrestrained) shrinkage of a material element is shown to depend approximately linearly 011 the humidity drop.