Environmental Engineering Reference
In-Depth Information
One important aspect here is the tendency to use ever higher concrete strengths for
building reinforced concrete towers in the future. The three-phase model is suitable for
describing the material behaviour of high-performance concrete (HPC), even ultra-
high-performance concrete (UHPC). One subproject in the “Sustainable building with
UHPC” programme of the German Research Foundation (DFG) focuses on the uniaxial
and multi-axial fatigue behaviour of UHPC.
It is very easy to see in Figure 3.15 how - starting from the brittle phase - the ductility
increases with increasing hydrostatic pressure. The figure also shows that the three-
phase model allows a very good approximation of the test results according to [39].
3.6.4 Constitutive models
In addition to the failure models, we require constitutive models with which we can
describe the deformation behaviour and damage development, elastic and non-elastic
behaviour, strain hardening and softening. Constitutive models for concrete are
described in various sources, for example [38,43].
As a starting point for further deliberations, the reader is referred to the non-linear-
elastic model with isotropic damage described in [8].
