Chapter: Civil : Construction Materials: Lime, Cement, Aggregates, Mortar
Low Heat Portland Cement (IS:12600)
Low Heat Portland Cement (IS:12600)
Low Heat Portland Cement (IS:12600) To limit
the heat of hydration of low heat Portland cement (LHC), the tricalcium
aluminate component in cement is minimised and a high percentage of dicalcium
silicate and tetracalcium alumino ferrite is added. The heat of hydration
should not be more than 272 and 314 J/g at the end of 7 and 28 days
respectively. The rate of development of strength is slow but the ultimate
strength is same as that of OPC. To meet this requirement, specific surface of
cement is increased to about 3200 cm2/g.
Properties: Less heat is evolved
during setting low heat Portland cement. When tested by Le Chatelier method and
autoclave test the expansion should not be more than 10 mm and 0.8%,
respectively. The minimum initial setting time should not be less than 60
minutes, and the final setting should not be more than 600 minutes.
The
compressive strength should be as follows.
72
± 1 hour 10 N/mm2
168
± 2 hours 16 N/mm2
672
± 4 hours 35 N/mm2
Uses:
It is most suitable for large mass concrete works such as dams, large raft
foundations, etc. Related Topics