The test of normal consistency of cement with Vicat’s apparatus to determine the percentage of water to achieve a specific consistency. The standard range of values is between 22 to 30 percent by weight of dry cement. In addition, this lab experiment helps to understand the range of plasticity and to know the duration of working time of specific cement.
The Objective of Normal Consistency of Cement
This experiment aims to understand the water-cement ratio to determine the standard strength of cement and its characteristics during the hydration process.
Reference Standard:
This experiment method conforms to the ASTM standard requirements of specification C 187
Need to apparatus for executing this test
- Electronic Balance: Sensitive to 0.1 gm
- Glass: Capacity should be 200 to 250 ml
- Mixing Machine
- Small Trowel
- Glass Plate: Should be 3 to 4 inches
- Vicat’s:
- Weight of movable rod: 300 (+-)0.5 g
- Diameter of the plunger end of rod: 10 (+-)0.05 mm
- Diameter of needle: 1(+-)0.05 mm
- Height of ring: 40 (+-)1 mm
- Inside diameter of the ring at the bottom: 70 (+-)3 mm
- Inside diameter of the ring at the top: 60 (+-)3 mm
Procedure
Firstly, We should weigh out 300 gm of dry cement and place the blank mixing plate. (The water required for Normal Consistency of Cement in a range of values between 22 to 30 percent by weight of dry cement) We will take water as 25, 28, and 30 percent of the weight of 300 gm of cement.
- Fix and place the Vicat apparatus on a flat surface and make the necessary adjustment.
- Then make a cement past and fill the Vicat ring and remove extra cement past by the trowel.
- Now place the Vicat mould on the Vicat apparatus and release the plunger gently by contacting the cement paste surface.
- And allow it to penetrate the cement paste and note down the reading from the gauge scale from the bottom of the Vicat mould.
- Similarly added water at 28 and 30 percent of 300 gm of dry cement, and note down the all reading.
Results of Normal Consistency of Cement Test
| Sample 01 | Sample 02 | Sample 03 | |
| Weight of cement (gm) | 300 | 300 | 300 |
| Percentage of Water | 25 | 28 | 30 |
| Penetration (mm) | 4.5 | 5.0 | 5.5 |
Remarks: The cement was not new, and it absorbs some moisture from the weather. So the determination of this test could be some error too.
Conclusion
The normal consistency to determine the percentage of water for specific consistency in the cement paste. The ASTM range is between 22 to 30 for 10 mm penetration by the standard Vicat’s apparatus.