PORTLAND CEMENT SPECIFICATIONS:
Standard grey Portland cement for
construction grade opc 42.5n / r
according to British standards
bs en 197 2000 or as tm c-150.
gost 10178-85 (Russian standard)
chemical composition of Portland cement unit allowable rate
silicon dioxide (sio2)% 20.0 - 23.0
aluminum oxide (al2o3)% 4.5 - 6.0
ferric oxide (fe2o3)% 3.1 - 6.0
calcium oxide (cao)% 64.0 -68.0
magnesium oxide (mgo)% 1.0 - 5.0
sulphur trioxide (so3)% 1.9 - 3.0
loss of ignition (loi)% 0.9 - 3.0
insoluble residue% 0.1 - 0.7
tricalcium silicate (c3s)% 50.0 - 60.0
dicalcium silicate (c2s)% 14.2 - 25.0
tricalcium aluminate (c3a)% 6.0 - 9.5
tric. alumino ferrice (c4af)% 8.5 - 11.6
chromium (cr)% 2.0max
physical and mechanical properties of cement
options portland unit allowable rate
autoclave expantion mm 0.02
normal consistency% 27.5
time of setting (vicat)
initial set hours: min 3.25 - 4.50
final set hours: min 4.54 - 6.00
fitness index cm2/gm 2800 - 3040
the resistance of portland cement in compression:
3 days mpa (kg/cm2) 10.0 - 34.2
7 days mpa (kg/cm2) 37.3 - 42.5
28 days, mpa (kg/cm2) 52.8 - 54.6