TY  - SER
AU  - Jorg Bockhold
TI  - 3D Material Model for Nonlinear Basic Creep of Concrete
SN  - 1598-8198
KW  - Concrete
KW  - Creep
KW  - Damage
KW  - Plasticity
KW  - Finite-Element Analysis
N2  - A new model predicting the nonlinear basic creep behaviour of concrete structures subjected to high multi-axial stresses is proposed. It combines a model based on the thermodynamic framework of the elasto-plastic continuum damage theory for time-independent material behaviour and a rheological model describing phenomenologically the long-term delayed deformation. Strength increase due to ageing is regarded. The general 3D solution for the creep theory is derived from a rate-type form of the uniaxial formulation by the assumption of associated creep flow and a theorem of energy equivalence. The model is able to reproduce linear primary creep as well as secondary and tertiary creep stages under high compressive stresses. For concrete in tension a simple viscoelastic formulation is applied. The material law is then incorporated into a finite element solution procedure for analysis of reinforced concrete structures. Numerical examples of uniaxial creep tests and concrete members show excellent agreement with experimental results
UR  - DOI: 10.12989/cac.2007.4.2.101
ER  -