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SV Technocrats India’s Vicat Needle Apparatus is used to determine the consistency, setting time, and soundness of cement, mortar, and other binding materials. It is a key instrument in cement testing as per IS: 4031 (Part 4 & 5), ASTM C191, and BS 4550.

Components of Vicat Needle Apparatus

  1. Vicat Frame – A vertical stand with a graduated scale for precise penetration measurements.

  2. Plunger (for Consistency Test) – A 10mm diameter cylindrical needle used to measure the standard consistency of cement.

  3. Needles (for Setting Time Test):

    • Initial Setting Time Needle – 1.0mm diameter with a cross-sectional area of 1mm².

    • Final Setting Time Needle – Similar but with an additional annular collar.

  4. Vicat Mould – A conical or cylindrical mould (internal dia: 70mm at top, 80mm at base, height 40mm).

  5. Glass Base Plate – Provides a stable platform for testing.

Tests Conducted Using Vicat Needle Apparatus

1. Standard Consistency Test (IS 4031 Part 4)

  • Determines the water content required for a cement paste to achieve standard consistency.
    Procedure:

  1. Prepare a cement paste and fill it in the Vicat mould.

  2. Lower the 10mm plunger onto the paste.

  3. Record the penetration depth – Standard consistency is achieved when penetration is 5-7mm from the base.

2. Initial & Final Setting Time Test (IS 4031 Part 5)

  • Measures the time taken for cement paste to begin hardening (initial setting time) and to completely set (final setting time).

Procedure:

  1. Prepare a cement paste of standard consistency.

  2. Insert the Initial Setting Time Needle onto the paste at regular intervals.

    • Initial Setting Time: Time when penetration reaches 5mm from the bottom.

  3. For Final Setting Time, replace with the Final Setting Needle.

    • Final Setting Time: Time when the needle no longer makes an impression on the surface.

Applications of Vicat Needle Apparatus

✅ Quality Control of Cement & Mortar – Ensures cement meets standard setting time requirements.
✅ Concrete Mix Design – Helps determine the correct water-cement ratio.
✅ Construction Industry – Essential for site and laboratory cement testing.