Specifications for Thatta Portland Blast Furnace Slag Cement

Thatta Cement Company Limited produces portland blast furnace slag cement (PBFS) meeting the requirements of Pakistan Standard PS 1631-1984(R) as follows:

 
Mechanical & Physical Properties
Thatta PBFS
Limits as per PS 1631-1984(R)
Compressive Strength (psi)
 3 Days
> 3000
 Not less than 2200
 7 Days
> 4200
 Not less than 3400
 28 Days
> 5900
 Not less than 5000
Setting Time - Minutes
 Initial
150 175
 Not less than 30
 Final
< 275
 Not less than 600
Soundness (Expansion)
 Le-Chatelier (mm)
< 1.00
 Not more than 10
Fineness
 Fineness-m2/kg
> 300
 Not less than 225
Chemical Requirements
Thatta PBFS
Limits as per PS 1631-1984(R)
 Lime saturation factor (LSF)
> 0.70
 Not greater than 1.02 and not less than  0.66
 Ratio of percentage of alumina to iron oxide
< 1.00
 Not less than 0.66
 Insoluble residue percent by mass
< 0.50
 Not more than 1.5%
 Sulphur content as sulphuric anhydride SO3
< 2.50
 Not more than 3.0%
 Loss on ignition-percent by mass
< 1.50 
 Not more than 3.0
 Magnesia-percent by mass
< 3.00
 Not more than 7
Typical Chemical Composition of Thatta PBFS is given below:
Chemical Compound
SiO2
Al2O3
Fe2O3
CaO
MgO
K2O
Na2O
SO3
Cl
Percentage by Mass
> 24.00
> 06.00
> 03.00
> 58.00
< 03.00
< 00.30
< 00.20
< 02.50
00.01
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