Determination of Standard Consistency of Cement IS: 4031 (Part 4) 1988

What is the consistency test of cement?

This test aids in determining the minimum amount of water needed to form the cement paste.

Why You Should Do Cement Consistency Tests?

* Quality Assurance

* Workability

* Setting Time

Standard Consistency Test

To Determine the percentage by mass of water to cement required to produce cement paste of desired
consistency. It is used in the determination of the initial and final setting times and soundness of

Principles Of Standard Consistency

  • The standard consistency range for cement is typically 26% to 33% by weight of dry cement.
  • Cement paste is considered to have reached standard consistency when a 10 mm plunger penetrates the paste to a height of 5 mm to 7 mm from the bottom of the Vicat mould.
Standard Consistency of Cement
Standard Consistency of Cement

Apparatus for Standard Consistency

  1. Vicat Apparatus IS: 5513-1976
  2. Needles
  3. Movable Rod
  4. Graduated Scale
  5. Vicat Mould
  6. Balance of capacity 1Kg ( 1gram )
  7. Graduates cylinder: to measure the water
  8. Trowel.
  9. Stop watch.
  10. Pan

Materials used

  • Ordinary Portland Cement ” OPC “
  • Water

Procedure For Standard Consistency

* The test will be conducted at a temperature of 27 ± 20°C and the relative humidity of the laboratory should be 65 ± 5%. 

* Mix a paste of 300g of cement with potable or distilled water, ensuring the gauging time is between 3 to 5 minutes and completed before any signs of setting. 

* The gauging starts from adding water to the dry cement until filling the mould. 

* Fill the vicat mould with the paste on a non-porous plate, 

* Smoothen the surface, and shake the mould slightly to remove air. 

* Only the operator's hands and the blade of the gauging trowel should be used in filling the mould.

* Place the test block with the impermeable resting plate under the rod supporting the plunger without delay. 

* Gently lower the plunger to make contact with the test block's surface and promptly release it, enabling it to sink into the paste. 

* Take note of the penetration depth. 

* Create trial pastes with different water percentages and conduct tests as outlined until the plunger is positioned 5mm to 7mm away from the base of the Vicat mould.

Calculation For Standard Consistency

                                                           Weight of water added
= Standard consistency (%) = ----------------------------------------------------- x 100
                                                           Weight of cement 

Weight of cement taken (g) = .................................
Initial percentage of water added to cement = ...............................
Quantity of water added to cement =.............................

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