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
Cement	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%