Demolition of concrete by thermal shock spallation: a mesoscopic numerical study based on embedded discontinuity finite elements
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Details
| Original language | English |
|---|---|
| Journal | INTERNATIONAL JOURNAL OF FRACTURE |
| DOIs | |
| Publication status | E-pub ahead of print - 2020 |
| Publication type | A1 Journal article-refereed |
Abstract
This paper deals with 2D (plane strain) and
axisymmetric numerical modelling of concrete frac-
ture processes under mechanical and thermal loading.
A mesoscopic modelling approach with an explicit rep-
resentation of aggregates as Voronoi polygons is cho-
sen while the concrete fracture model is based on rate-
dependent embedded discontinuity finite elements with
Rankine criterion indicating a new crack initiation. This
choice enables the study of the effects of inherent crack
populations on the response of concrete under mechan-
ical and thermal loading. In the numerical examples,
the performance of the present modelling approach is
first demonstrated in the uniaxial compression and ten-
sion tests under plane strain conditions. Then, the prob-
lem of thermal spallation of concrete surface under dry
conditions due to a high intensity, short duration heat
flux is simulated under axisymmetric conditions. The
underlying uncoupled thermo-mechanical problem is
solved with an explicit time marching scheme based
on the staggered approach. Different heat flux inten-
sities and heating times as well as combined effect of
surface roughness and pre-stress field are tested. The
simulation results suggest that demolition of concrete
structures by heat shock is a viable method.
axisymmetric numerical modelling of concrete frac-
ture processes under mechanical and thermal loading.
A mesoscopic modelling approach with an explicit rep-
resentation of aggregates as Voronoi polygons is cho-
sen while the concrete fracture model is based on rate-
dependent embedded discontinuity finite elements with
Rankine criterion indicating a new crack initiation. This
choice enables the study of the effects of inherent crack
populations on the response of concrete under mechan-
ical and thermal loading. In the numerical examples,
the performance of the present modelling approach is
first demonstrated in the uniaxial compression and ten-
sion tests under plane strain conditions. Then, the prob-
lem of thermal spallation of concrete surface under dry
conditions due to a high intensity, short duration heat
flux is simulated under axisymmetric conditions. The
underlying uncoupled thermo-mechanical problem is
solved with an explicit time marching scheme based
on the staggered approach. Different heat flux inten-
sities and heating times as well as combined effect of
surface roughness and pre-stress field are tested. The
simulation results suggest that demolition of concrete
structures by heat shock is a viable method.