Specifications for Thatta Sulphate Resistant Cement

Thatta Cement Company Limited produces sulphate resistant cement (SRC) meeting the requirements of Pakistan Standard PS 612-1989(R) as follows:

 
Mechanical & Physical Properties
Thatta SRC
Limits as per PS 612-1989(R)
Compressive Strength (psi)
 3 Days
> 3400
 Not less than 2200
 7 Days
> 4600
 Not less than 3400
 28 Days
> 6700
 Not less than 5000
Setting Time - Minutes
 Initial
≥ 120 ≤140
 Not less than 30
 Final
< 250
 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 SRC
Limits as per PS 612-1989(R)
 Lime saturation factor (LSF)
> 0.90
 Not greater than 1.02 and not less than  0.66
 Tricalcium Aluminate (C3A)
< 3.50
 Not less than 3.50
 Insoluble residue percent by mass
< 0.50
 Not more than 2.0%
 Sulphur content as sulphuric anhydride SO3
< 2.50
 Not more than 2.5%
 Loss on ignition-percent by mass
< 1.50 
 Not more than 3.0
 Magnesia-percent by mass
< 2.00
 Not more than 4
Typical Chemical Composition of Thatta SRC is given below:
Chemical Compound
SiO2
Al2O3
Fe2O3
CaO
MgO
K2O
Na2O
SO3
Cl
Percentage by Mass
> 22.00
> 04.00
> 05.00
> 62.00
< 02.00
< 0.40
< 0.20
< 02.50
0.005