Quality of cement
a. Good quality
- Should be stiffen or harden quickly.
- Should be early workable.
- Should have excellent binding property.
- Should possess a good plasticity.
- Should offer a good resistance to moisture.
- Should achieve required comprehensive strength.
b. Bad quality:
- It doesn’t gain required strength in specified period of time.
- It absorbs more moisture.
- It contains some harden particles, mixture in fine cement.
Selection and handling
- For RCC- cement should be 43 grade and should be used within 2 months of manufacturing.
- Cement bags should be airtight without any hole.
- Cement should be free of lumps.
- It should be stored in the water proof room.
Cement grade
- A 50 cm3 block is constructed with the amount and the load with which it cracks is measured and graded accordingly.
|
Cement grade |
Mpa |
kg/cm2 |
|
33 |
33 |
330 |
|
43 |
43 |
293 |
|
53 |
53 |
329 |