文档介绍：358 3 Deterioration of Materials and Structures
t
Ca-Concentration ci Ca-Concentration sh rate log(−∂sh/∂t) Damage d
Δt m
[1] 21 [mol/m3] 015 [kmol/m3] 0-2[kmol/[m3d]] ≤−61 [1] 0
100
200
300
400
428
Fig. . Chemo-mechanical analysis of a concrete panel: Distribution of the
calcium concentration c (pore fluid), the calcium concentration s (skeleton), the
dissolution rates ˙ and the scalar damage parameter dm at different states of exposure
Numerical Examples 359
40 -4
chemo-mechanical chemo-mechanical
mm]
[mm] 35
chemical 3 mechanical
2 -6
−
x
30 [10
A
front -8
2 25
20 -10
in point
2
15 s,
u -12
acm ac
10
-14
5 failure
failure
position of the Ca(OH)
0 displacement -16
0 30025020015010050 0 200 400 600 800 1000
√√
square root of time t [ d] ratio t/Δt [1]
Fig. . Chemo-mechanical analysis of a concrete panel: a) Temporal propaga-
tion of the Ca(OH)2 dissolution front along the clamped support, b) Deformation-
time relation
As a consequence of this (long-term) chemo-mechanical material degra-
dation and the continuous propagation of the crack the structural stiffness
decreases. This connected with a progressive growth of the vertical displac-
ments u of the right edge of the panel (Figure ). 94 years after the start
of the exposure to de-ionized water the resistance of the structure is finally ex-
hausted. Without consideration of chemo-mechanical couplings no structural
failure would have been predicted.
Numerical Simulation of a Concrete Beam Affected by
Alkali-Silica Reaction
Authored by Falko Bangert and G¨unther Meschke
The chemo-hygro-mechanical model for chemically expansive processes pre-
sented in Subchapter is applied to the durability analysis of an ASR-
affected concrete beam to predict the temporal deterioration of this structure.
Details of the analysis including the chosen model parameters are contained
in [83].
The left hand side of Fi