Suitability of the damage-plasticity modelling concept for concrete at elevated temperatures: Experimental validation with uniaxial cyclic compression tests

Strain-rate controlled cyclic compression tests enable us to explore the softening behaviour and the elastic stiffness evolution with increasing plastic straining of concrete in uniaxial compression. From such tests at ambient temperature, it is known that concrete exhibits the phenomenon of elastic stiffness degradation upon unloading—a macroscopic behaviour that can be captured by damage-plasticity models. However, the damage-plasticity concept has been implemented in some available finiteelement method codes as temperature-dependent concrete models which are often used today in structural fire engineering, despite the lack of experiment-based calibration data. This paper presents the results of an experimental study on the uniaxial behaviour of concrete at elevated temperatures under cyclic compressive loading. The experimentally derived evolutions of the elastic stiffness with increasing plastic straining (1) confirm the suitability of the damage-plasticity modelling concept for concrete in uniaxial compression at elevated temperatures and (2) provide novel temperature-dependent calibration data for damage-plasticity models.