1. New Progress on RollerCompacted Concrete Dams, Jia Jinsheng eta/. (eds)
© 2007 China WaterPower Prees, ISBN 978-7-5084-4994-4 .
Badovli Dam Thermal Analysis
Hamidreza Araghian
Project Manager& Concrete Specialist, LAR Consulting Engineers, Tehran, IRAN, E-mail: hra@hra.ir
Abstract: Badovli Dam will be located in North West of IRAN, in West Azerbaijan province near the Turkey
borders on the Aghsu River.The project is now under design and the main purpose of construction of Badovli
Dam is providing the potable water for Shoot,Bazorgan and Maku cities and water for agricultural purposes of
Bazorgan and some part of Poldasht.This dam is located in 16 km far from Maku city & 216 km from Urumia
the capital city of West Azerbaijan porvince. The mean annual air temperature in the dam-site is 8.9 degrees of
centigerade with minimum monthly average temperature of -3°C in the january.the maximum monthly average
temperature is 19.4 °C in July. Badovli is a roller compacted concrete dam with a total volume of 350,000 m3
(RCC volume is 290,000 m3
). Since the RCC will be placed in a short period of time, in order to choose a suitable
time schedule for constructuion, it is necessary to to calculate the generated heat and resultant stresses. In this
project the RCC will be placed in 0.3 m lifts that is conventional for RCC dams.
The two major type of cracking in the RCC dams including surface gradient cracking and mass gradient
cracking have been investigated. The surface gradient cracking specially have a great degree of importance
because of very cold winters. Mass gradient cracking doesn't occur based on the analysis have been performed.
Key words: Badovli Dam, thermal analysis, cracking
1 Introduction
Based on ACI 207.1R, Mass concrete is any volume of
concrete with dimensions large enough to require that
measures be taken to cope with the generation of heat
from hydration of the cement and attendant volume
change to minimize cracking. Since the mass concrete
structures (and RCC dams) are poured in many lifts
and layers, the effect of the time interval between
successive lifts , temperature of fresh concrete and the
boundary conditions during construction should be
taken in to account when the thermal regime in the
structure is calculating. In a thermal analysis, the
differential equation of heat is solved by considering
the boundary conditions. Eq.l shows the transient form
of heat differential equation.
a~ a~ a~ aTkx;x-2 +kYY
-
2 +kV.-2+w=pc- (1)
ax ()y az at
In this equation, k, w, p, c, T are conductivity,
generated heat, density, specific heat and temperature
of the body respectively.
Boundary conditions should be defmed carefully for
solving this equation. Contact of concrete with air (or
water) and rock are examples ofthis boundary condition.
When the concrete surface is in touch with a fluid
(like air) concrete cools down via convection. The
convection coefficient depends on the type of fluid
and its velocity. Convection coefficient increases with
fluid velocity increment. So continuous curing has and
important role in cooling concrete and should not be
neglected in thermal analysis.
When the concrete is in contact with another
infinite solid like rock or soil, the temperature of these
boundaries may be considered constant and equal to
the average temperature of the the air.During the
process of cement hydration some heat liberates. The
amount of produces heat depends on the cement type,
chemical composition and size of cement grains.
Since cement hydration is a thermo-activated
reaction, the rate of hydration will be increased by
temperature increment. (Fig. 1)
Freiesleben and others (1977) developed the
equivalent age maturity function, shown in (2), based
on the Arrhenius rate theory for chemical reactions.
The equivalent age maturity function converts the
chronologie curing age t of a concrete cured at any
concrete temperature Tc to an equivalent curing age te for
a specimen cured at a specific reference temperature T,..
(2)
615

2. 3 Analysis assumptions
The following assumptions have been applied in the
current analysis:
(1) Concrete is considered Isotropic & Homogeneous
consequently all of the thermal properties are the same
in all directions.
(2) Thermal and structural properties of concrete are
constant for all of temperature and time intervals.
(3) The Nonlinear effect of temperature on heat
generation rate has been considered in the analysis.
This is an important factor in calculation of temperature
in concrete.
(4) The Analysis will be performed in the plane of
the dam. (2 - dimentional thermal analysis)
(5) The Compressive strains in the dam body will be
neglected conservatively.
may occure in the colder months of the first or second
year after the construction. These type of cracks are
nearly closed after reduction of the Surface thermal
gradient .
Mass gradient cracking of concrete can be visible
after final cooling of the internal part of the mass and
this may take even many years.
4 Dam section geometry
Fig. 2 shows the largest block of the dam. The crest
elevation is 1,664.5 m. the height of dam is 98.8 m. The
lower part of main monolith, acts as cofferdam during
construction. The embedded parts such as irrigation
and water intake pipes have been located in this part.
Since this part of the dam should be constructed in
the diyersion stage and RCC mixes may not be
available at that time. based on the proposal of the
contractor this part may'be constructed as Conventional
concrete.
~
= T2
>T1
.9
~
.a
£~
0
v
e00
v
"0
t2
t1
time
All
J1
Where: te is equivalent age at reference curing temperature;
dt is chronological time interval, h;
T is average concrete temperature during time
.interval dt;
To is reference temperature, °C (20°C or 293 K
for cement);
Eo is activation energy, J/mol and R is universal
gas constant.
Heat generation of the concrete is also a function of
time. This function can be expressed as below form:
Q=Qm(l-e-m.tcr
) (3)
In the above equation, Qm is total heat of concrete,
m is a coefficient depends on the Type of cement, and
te is the equal age which can be calculated based on
Maturity of concrete.
Tensile stress due to the concrete cooling can be
expressed as Eq. (4):
u=k . a . E . iYl' (4)
In this equation, compressive stresses have been
neglected conservatively. This is due to the higher
creep in the early ages after concrete placement. k is
the total restraint (foundation and geometry), E the
elasticity modulus and aT the cooling degree of the
concrete element in the dam.
Fig. 1. Factors affecting the degree of hydration of concrete
2 Thermal cracking in RCC dams
7 +1,653.5
Two different types of Thermal cracking can be
expected in Conventional Concrete and Roller Compacted
concrete dams: Mass Gradient cracking & Surface
gradient cracking.
Surface gradient cracking caused by the tensile
stresses induced due to the temperature difference
between surface and internal part of the massive
concrete structure. Mass gradient cracking is a dangerous
the~ cracking that caused by restraint against the
movement of total mass of the dam during cooling up
to the fmal stable temperature. these type ofcracks can
c~use large amount ofleakage in concrete dams.
Normally Surface gradient cracks are narrower and
616
0.85
Rce
g 1,58820
evc
Fig. 2 Typical Cross Section of Badovli Dam
The lower part modelled in 1 meter lifts with time

3. interval of 5 days. This is due to the lack of pre-cooled
aggregates in that time. The RCC part will be
constructed in 0.3 m lifts and 1 day between two
successive list left. Upstream and downstream face
concrete thicknesses are 1.5 & 1.0 meter of air
entrained concrete to provide enough durability against
freezing and thawing.
5 Environmental condition
Continue
Property Rce eve
Thermal Expansion Coeff. 8.8xl0-6
8.8xI0-6
Elasticity Modulus (Gpa) 18 22
Tensile strain capacity-Rapid 80J.l 100 J.l
Tensile strain capacity-Slow 110 J.l 150 J.l
Poisson ratio 0.2 0.2
6 Concrete mix designs
Based on mentioned results, the Qm and m will be
72 callgram and 0.206 respectively.
Based on the Laboratory results, RCC and CVC mix
designs consist of 160 kg and 220 kg of cementitious
materials respectively. Cement Type is Natural Portland
pozzolanic Cement (IP). the results of heat of hydration
test (Based on ASTM CI86), is in the Table 1.
Table 1 Heat of hydration of Uromia IP
cement based on ASTM C186
8 Finite element model
ANSYS finite element program was applied for
modeling and analysis. This software has excellent
capabilities of modeling concrete structures temperature
& construction procedure effect on the internal
temperature of the dam. The Model consists of 2,193
PLANE77 Elements and 6,871 Nodes. This type of
element, with its great features, enables user to model
temperature in the dam body. By using kill option, the
user will be able to model construction effects .The
geometry of the generated mesh for BADOVLI has
been modified to present a reliable model for getting
the required data's.
BADOWLI THERMALANALYSIS
72
28 d
Heat of hydration(caVg)
55
7d
Badovli Dam site is a cold region; the average annual
temperature of dam-site is about 8.9 °C. The sinusoidal
function of the temperature in Badovli may be
expressed as below:
Temp(t) = 8.2 +11.2sin 27[(t - 95) (5)
365
Where: t is the temperature and t is time in days from
beginning of the year. The maximum and minimum
monthly average temperature is 19.4 °C and -3°C
respectively.
7 Thermal and structural properties Fig. 3 Meshed dam body
Thermal and structural properties are shown in the
Table 2. . 9 Placing Temperatures
617
Property RCC cvc
Thermal diffusivity(m2
/d) 0.113 0.113
Specific heat [J/(kg.oC)] 950 950
Density (kglm3
) 2,420 2,420
Thermal Surface transmit ion-
60 60coeff [kcall(m
2
.h·C)]
..... ,
Table 2 Thermal & structural properties
of RCC and evc
According on US Army the placing temperature of the
roller compacted concrete calculated as Table 3.
Based on these temperatures, RCC shall be started
in the February and ended in the November Before the
temperature falling below 5 °C. during the winter
RCC shall be protected form the low temperatures. in
the next year RCC placing will be started in February
again. Time interval between successive lifts is about
1 day, and a maximum volume of 1,500 m3
/d predicted
to be placed.

4. Table 3 Ree and eve placing temperatures
RCC Placing Temperature in BADOVLI Dam
Jan.* Feb.* Mar. Apr. May June July Aug. Sep. Oct. Nov.* Dec.*
- 8.9 10 10 10 10 10 10 8.5 - -
* Indicates that in these months the placing should be stopped.
1.00 P""-lIlii~--r---,----r-------r---....,.--------.
A =0.035,825
B =0.188,592
C =0.341, 359
D =0.494, 127
E =0 .646, 894
F =0.799, 661
G =0.952, 428
H = 1.105
I 1.258
and restraint is high. So it is reasonable to expect mass
concrete gradient cracks are started from the middle
part.
Fig. 5 Restraint factor for Badovli Dam body (perpendicular
to dam axis)
Restraint factors of Fig. 4 & Fig. 5 .are calculated
based on the overall cooling of dam, While in a real
case, because of differential cooling of the dam, these
restraints may be increased. This effect bas been
considered in the current analysis for Badovli Dam.
It sh?uld be noted that the mass gradient cracking
sball be checked along dam axis and perpendicular to
dam axis. Cracking perpendicular to dam axis
(transverse cracks), will endanger the water tightness
and longitudinal cracking may divide dam section in
to two or more column that will oscillate separately
during the earth quake and the dam may not be stable
in this condition.
11 Surface gradient analysis
6040 50
Height above foundation (m)
---- Joint-dist=45m.
-._. Joint-dist=9Om
3010
--+-Joint-dist=30m
-Joint-dist=15m
0.90 tfr;;-~~---+---I----+---+-----I
6
] 0.80 t-t-~~---+---+----+---1--~
.s 0.70 ~1f-T-+~--+---+----+---1-----I
CI:S
~ 0.60 ~t"*-T+-~-+---I----+---+-----I
~
0.50 t--....-t.....,...------.,;=v---+----+---I--~
0.40 t---t:::-T-t'~-~T_-+----+---1--~
0.30 t---t----r.:~--+--~+----+---+--___I
020 J----t-+r-~-+---~~-+---I--___I
0.10 I----,...-+-~r_i~--I---~---I--___I
'''-0.00 1....-----.-~.....~~I:lI:::l1IIiI...~t__~. . . . ....._...
o
10 Restraint Factors
Restraint factor for badowli dam -along crest
( crown-cantilever)
Restraint factors in dam body calculated by using a
comprehensive 3d model. The results have been
shown in the Fig. 4 & Fig. 5.Transverse joint spacing
has a major effect on the restraint factor and tensile
thermal stresses induced in dam body parallel to dam
axis.
When total volume of the dam body cools down
simultaneously and homogenously, the foundation
restraint effect may decrease the stresses. Because this
is not true due to the variations in peak temperature of
concrete in different points, so it is reasonable to
neglect this effect.
So the low modulus of the foundation rock may
decrease the thermal stresses of dam body slightly, but
in the analysis this effect has been neglected
conservatively.
618
Rg. 4 Restraint factor for Badovli Dam with different contraction
joint spacings (along dam axis)
As shown in Fig. 4, when the joint spacing increases,
the restraint against thermal movement of the dam
also increases for a specified point in the dam, and
restraint in the middle part is higher than 'that of
upstream and downstream faces. So it is reasonable to
e~pect that mass gradient cracks to be started from the
. middle part of the dam where both of the temperature
Because Badovli Dam has been located in a cold
region, the temperature gradient between core and
surface may cause cracking so it is necessary the
strains shall be calculated in the analyses and the
surface tensile strain shan be checked to be less than
cr~ckiDg strain for the concrete with consideration of
contraction joint effects.
Fig. 6 shows induced strains in the dam body after
placing 20 meters ofevc in the lower part of the dam.

5. As can be seen, the maximum tensile strain is
117micro in z direction, which is higher than short-term
tensile strain capacity of the CVC (Table 2). The crack
spacing will be more than 50 meters that is higher than
maximum joint space, so the cracking doesn't occur.
Internal part of the dam is under compressive
strains that can be tolerated by RCC safely. After
ending the frrst winter, surface of concrete will be
covered by roller compacted concrete, so the fIrst
winter is almost the worst condition for this concrete
form thermal stresses view point.
It is planned that the major part of the aggregate to
be produced in the colder months. RCC should be
placed with a temperature not more that 10°C.
Since the most probable occurrence time of the
surface gradient cracking is the first or second winter
The Isothermal and strain contours have been shown
in these two seasons (Fig. 7 and Fig. 8). As it can be
seen the maximum tensile strain in the second winter
due to temperature gradient is 160 micro that is more
than tolerable strain by RCC (100 micro strain).
Because the contraction joints in the dam, are
designed to be located at a maximum 19 meters
distance, and this tensile strain may produce a
cracking distance about 33 meters so the cracking
doesn't occur. So the dam is safe against surface
cracking.
BADOWLI THERMAL
ANAL YSIS
ANSYS5.4
DEC 12005
22:45:06-
Nodal solution
TIME=155
TEMP (AVG)
RSYS=O
Power graphics
EFACET=1
AVRES=Mat
SMN=- 3.307
SMX=24.989
A =-1.735
B =1.409
C =4.553
D=7.697
E =10.841
F =13.985
G =17.129
H =20.273
I =23.417
BADOWLI THERMAL
ANAL YSIS
ANSYS5.4
DEC 1 2005
22:51:56
Nodal solution
STEP=1
SUB=1
TIME=1
EPTOZ (AVO)
RSYS=O
Power graphics
EFACET=1
AVRES=Mat
DMX =0.001,504
SMN =-0.882E-04
SlvIX =0. 160E-03
A =- 0.744E-04
B =-467E-04
C =-191E-04
D =0.851E-05
E =0.361E-04
F = 0 .638E-04
G =0.914E-04
H =0.119E-03
I =0.147E-03
Fig. 6 Isothermal contours (left) and thermal strains (right) in the lower part (CVC) of the dam body
BADOWLI THERMAL
ANAL YSIS
BADOWLI THERMAL
ANAL YSIS
ANSYS5.4
DEC 2 2005
19:34:23
Nodal solution
STEP=1
SUB=1
TIME=1
BFETEMP (AVG)
DMX =0.003, 307
SMN =-3.887
SMX=29.442
A=- 2.036
B=1.668
C=5.371
D=9.074
E=12.777
F=16.48
G=20.148
H=23.887
1=27.59
ANSYS5.4
DEC 2 2005
19:34:37
Nodal solution
STEP=l
SUB=I
TIME=1
EPTOZ (AVG)
RSYS=O
Power graphics
EFACET=l
AVRES=Mat
DMX = 0 .003, 301
SMN =-0.143E-03
SMX =0.I64E-03
A=-0.126E-03
B =-0.917E-04
C =- O. 576E- 04
D =-0.235E-04
E =0.105E-04~.-:::...- --r- ....:::..-~ F =0. 446E-04
G =0.787E-04
H =0.1l3E-03
I =0.147E-03
Fig. 7 (Left) Isothermal contours at second winter (Right) thermal strain in the dam body in the second winter
(at 540 days after starting the construction of the dam)
12 Mass gradient cracking
In order to investigate the mass gradient cracking
occurrence, the temperature history in different
locations of dam body have been calculated by using
the Finite element model. The cooling of dam body up
to 4,500 days after start of the construction, have been
modeled. The maximum temperature in the dam body
is 30.4 °C. The maximum mass gradient in the dam
body is 26.1 °c in the height of 52 meters of the dam.
This Gradient produces a crack distance of 50 m that
is more than maximum contraction joint distance of
619

6. dam body and mass gradient cracking doesn't occur.
The Temperature histories at different nodes are
shown in the Fig. 9. Node 3,554 is in the middle part
of the dam and in the height of 49 meters above the
foundation. Node 3,830 is Near Upstream face at the
same height. So due to the effect of the surrounding
air, some temperature oscillation can be seen in this
node. Node 4,031 is also in the middle part between
upstream and downstream of the dam and 54 meters
above the foundation. After almost 3,500 days, the
dam body reaches to its final stable temperature that is
8.5 C for Badovli Dam.
Because of 3 d nature of real temperature flow, the
real temperature history might show some discrepancy
from the analysis results. However, the maximum and
minimum temperature will be the same.
ANSYS5.4
DEC 2 2005
17:34:46
Nodal solution
TIME =400
TEMP (AVG)
RSYS=O
Power graphics
EFACET=1
AVRES=Mat
SMN=5
SMX=30.22
A =6.401
B=9.203
C=12.006
0=14.808
E =17.61
F =20.412
G=23.215
H=26.017
1=28.819
ANSYS5.4
DEC 2 2005
17:34:11
Nodal solution
TIME=lOOO
TEMP (AVG)
RSYS=O
Power graphics
EFACET=l
AVRES=Mat
SMN =3.483
SMX=23.841
A =4.614
B =6.876
C =9.138
0=11.4
E =13.662
F =15.924
G =18.186
H=20.448
1=22.71
Badowli thennal analysis Badowli thermal analysis
Fig. 8 (left) Isothermal contours at 400 days after start (right) Isothermal contours at 1000 days after start of placing
Temperature history ofdifferent nodes
35 r----..,-----,------,------r------,
e30 1---.r.--+----4-----I-----+----I
G)
·S 25 t--l ~+----4-----I-----+----I
G
~ 20
~ 15 1--t-t-'"'II'-ir+:PI--..~~----I-----+----I
10 I-JjL-Y-+J-U~~~~-i..£.rL_~
51----+---=---JlL-Y~~~I:.f.-_t.:H___Ir¥_-___I
o 1,000 2,000 3,000 4,000 5,000
TlJDe(d)
-Node 35S4 .......Node 3830 ---Node 4031
Fig. 9 Temperature history at different nodes
13 Conclusions
All of the analyses were done based on the RCC
placement in 9. months. Based on analysis no major
crack which endangers dam performance and its water
tightness is expected in future.
In this design stage analysis, the foundation restraint
factor considered to be 100%.
(1) The heat liberation rate of the cement has a
great influence on the heat storage in the concrete
. inass. So including the effect of temperature on cement
hydration in the thennal analysis of RCC dams, especially
in cold areas, results in higher peak temperature in the
concrete. This is due to the retarding effect of low air
temperature on hydration of concrete.
(2) Controlling Surface gradient cracking especially
in the cold regions has a great degree of importance.
Because surface cracking may be harmful for water
tightnes.s of the dam.
(3) fu the lower part of the dam, restraints against
movement of the dam due to the thermal shrinkage are
high so the risk of thermal cracking will be higher in
this part. In the Badovli Dam, the maximum temperature
of lower part has been limited to 25°C to control
cracking parallel to dam axis and between contraction
joints.
References
[ 1] ACI 207.2R - 95. Effect of Restraint, Volume
Change, and Reinforcement on Cracking of Mass
Concrete
[2] ACI 207.1R. Mass Concrete
[3] ACI 207.4R. Cooling and Insulating. Systems for
Mass Concrete
[4] ACI 209.R. 92. Prediction Of Creep, Shrinkage
and Temperature Effects in Concrete Structures
[5] ASTM CI074. Standard Practice for Estimating
620

7. Concrete Strength by the Maturity Method
[6J ANSYS 5.4ADPL. User's Manual
[7 J F.R.Andriolo. The Use of Roller Compacted
Concrete
[ 8J Bentz and de Larrard, "Prediction of Adiabatic
Temperature Rise in Conventional and High
Performance Concretes Using a 3-D Micro structural
Model". Cement and Concrete Research
[9J P, Kumar Mehta & Paulo. J. Monteiro. Concrete:
Microstructure, Properties, and Materials
[ 10J Andrade, F.R.Andriolo, Thennal Analysis of Roller
Compacted Concrete
[ 11] Hamidreza Araghian, Thermal Analysis of
RAEESALI DELVAJU dam
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