ABSTRACT
Deformation of concrete results both from environmental effects, such as moisture gain or loss and heat, and from applied stress, both short and long term. This chapter discusses the mechanisms and the factors influencing the magnitude of all of the components of this behaviour, that is, shrinkage, elastic response and creep, and also considers thermally induced strains. It concerns the behaviour of hardened cement paste (hcp) and concrete when mature, but some mention of age effects will be made. In principle, the stronger the hcp structure, the less it will respond to the forces of swelling or shrinkage. Since shrinkage results from water loss, the relationship between the two is of interest. The surface of both solid and liquid materials will be in a state of tension due to the net attractive forces of the molecules within the material. The mechanisms described above concern the free and adsorbed water.
