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.
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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):
o Initial Setting Time Needle – 1.0mm diameter with a cross-sectional area of 1mm².
o 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.
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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.
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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.
o Initial Setting Time: Time when penetration reaches 5mm from the bottom.
3. For Final Setting Time, replace with the Final Setting Needle.
o Final Setting Time: Time when the needle no longer makes an impression on the surface.
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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.
