Rapid Hardening Portland Cement (IS: 8041)
Rapid Hardening Portland Cement (IS: 8041) has high lime content and can be obtained by increasing the C3S content but is normally obtained from OPC clinker by finer grinding (450 m2/kg). The basis of application of rapid hardening cement (RHC) is hardening properties and heat emission rather than setting rate. This permits addition of a little more gypsum during manufacture to control the rate of setting. RHC attains same strength in one day which an ordinary cement may attain in 3 days. However, it is subjected to large shrinkage and water requirement for workability is more. The cost of rapid hardening cement is about 10 per cent more than the ordinary cement. Concrete made with RHC can be safely exposed to frost, since it matures more quickly.
Initial setting time 30 minutes (minimum)
Final setting time l0 hours (maximum)
1 day 16.0 N/mm2
3 day 27.5 N/mm2
Uses: It is suitable for repair of roads and bridges and when load is applied in a short period of time.