Bonded Concrete Overlays: A Brief Discussion on Restrained Shrinkage Deformations and Their Prediction Models

Bonded concrete overlays (BCO) on bridge decks are beneficial solutions due to their superior properties as compared to the typical asphalt pavement. A significant number of overlays suffer however, from occurrence of cracks and delamination due to poor bond, and restrained shrinkage and thermal dilation. Over the past years different appraisals for estimation of the restrained deformations have been developed, from micro-scale models, based on poromechanics, to empirical equations as given in B3 or B4 models suggested by Bažant. This paper provides a short overview of calculation models along with a brief theoretical explanation of shrinkage mechanism.