Case study of EXTREME WEATHER CONCRETING




  
In the present case requirement of concrete temperature is 23° C at the time of mixing and 27° C at the time of placing as furnished by the customer. 

The calculations for quantity of ice to be added in the form of flakes are shown in Tables for both grades of concrete.  However, actual trials shall be done at the site and temperatures be measured.  Necessary adjustments may be done depending upon actual site conditions

CALCULATIONS FOR M30 GRADE OF CONCRETE (TYPICAL)

Material
Mass
(kglcu.m)
Specific
heat
(kJlkg.k)
Joule of vary
temperature
by 1° C
Initial
temperature of
material
C)
Total joule
in material
1
2
3
2x3=4
5
4x5=6
360
0.92
331.2
40
13248
Water
122.8
4.184
513.8
30
15414
Aggregate
1828.2
0.92
1681.9
37
62230.3
Ice
50
4.184
209.2
0
0
Ice (Fusion)
(-)50x33.5
kj/kg)


______________
-16750.0

Total

2736.1

74136.3
Concrete temperature
=
Column 6
Column 4
=
74136.3
2736.1
=
27° C

Percentage of water substituted by ice flakes = 29%                       since{(50/172.8) = 0.2893}
CALCULATIONS FOR M35 GRADE OF CONCRETE (TYPICAL)


Material
Mass
(kg/cu.m)
Specific
heat
(kJ/kg.k)
Joule of vary
temperature
by 1° C
Initial
temperature of
material
C)
Total joule
in material
1
2
3
2x3=4
5
4x5=6
Cement
410
0.92
377.2
40
15088
Water
168.1
4.184
703.3
30 I
21099
Aggregate
1799.9
0.92
1655.9
37
61268.3
Ice
50
4.184
209.2
0
0
Ice
(Fusion)
(-)50x33.5
kj/kg)



-16750.0

Total

2945.6

80705.3

Concrete temperature
=
Column 6
Column 4
=
80705.3
2945.6
=
27° C


Percentage of water substituted by ice flakes = 29%




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