Concrete Structures Under Restraint Forces (Betongkonstruktioner under Tvangsbelastning)

摘要

When a loaded concrete specimen is drying, the observed deformation is significantly larger than the sum of the deformation of a loaded damp specimen and a nonloaded drying specimen. The excess deformation is often referred to as stress induced shrinkage or as drying induced creep. The aim of the present work is to describe this effect theoretically. Finite element analyses of concrete specimens are performed, using a material model for concrete, where softening and environmental influence are regarded. The softening is modelled by a smeared crack approach based on the fictitious crack model. The drying induced strain is assumed to be dependent not only on the change of moisture content, but also on the current stress state. Comparisons of the theoretical behavior and experimentally observed phenomena are made. (Copyright (c) Valtion teknillinen tutkimuskeskus (VTT) 1987.)