1 Department of Structural Engineering and Materials, Technical University of Denmark
A composite-rheological model of concrete is presented by which consistent predictions of creep, relaxation, and internal stresses can be made from known concrete composition, age at loading, and climatic conditions. No other existing "creep prediction method" offers these possibilities in one approach.The model is successfully justified comparing predicted results with recent experimental data obtained in tests made at the Danish Technological Institute and at the Technical University of Denmark on creep, relaxation, and shrinkage of very young concretes (hours) - and also with experimental results on creep, shrinkage, and internal stresses caused by drying shrinkage reported in the literature on the mechanical behavior of mature concretes.Shrinkage (autogeneous or drying) of mortar and concrete and associated internal stress states are examples of analysis made in this report. In this context is discussed that concrete strength is not an invariable material property. Based on the overall positive results reported it is suggested that creep functions needed in Finite Element Analysis (FEM-analysis) of structures can be established from computer-simulated experiments based on the model presented - calibrated by only a few real experiments.