Grade of Cement:
In India, the following grades of cement are used for roads :
Ordinary Portland Cement (OPC)
- Grade 33
- Grade 43
- Grade 53
Portland Pozzolana Cement (PPC)
- Blast Furnace Slag Cement
For heavy duty concrete pavements, where a high strength is required, OPC Grades 43 and 53 are used, whereas OPC Grade 33 is used for light duty concrete pavements. PPC and Blast Furnace Slag Cement are also used for concrete roads.
Fly-ash, which is an industrial waste, can replace upto 35 per cent of cement without losing strength. In fact, it has beneficial properties like less heat of hydration (and hence less shrinkage cracks) and increase in strength over a period of time.