Flow / Flow Table Test

Flow / Flow Table Test

Key Concepts:

1. Flow Test:

   • Assesses the consistency of fresh concrete.
   • Determines the ease with which concrete flows.

2. Flow Table Test:

   • Specific method used to measure the flow of concrete.

Instruments:

• Flow Table: A flat, circular table on which the concrete sample is placed.
• Mold: Typically cone-shaped, used to form the concrete sample.
• Measuring Tools: Scale or calipers to measure the spread of concrete.

Test Procedure:

1. Place the flow table on a level surface.
2. Fill the mold with the concrete sample.
3. Lift the mold vertically to release the concrete.
4. Drop the flow table from a specific height (25 mm) several times (usually 15) to spread the concrete.
5. Measure the diameter of the spread concrete in two perpendicular directions to calculate the flow.

Formulas:

• Flow (%) = [(Diameter1 + Diameter2) / 2 - Initial Diameter] / Initial Diameter × 100

Results Interpretation:

• Higher flow percentage indicates higher workability of concrete.
• Ideal flow values depend on specific construction requirements and standards.

Notes:

• Ensure mold and table are clean and free from any previous concrete residue.
• Uniformity of dropping height and the number of drops are critical for accurate results.
• Test should be conducted in a controlled environment to minimize variability.

Applications:

• Used in quality control during concrete production.
• Helps in adjusting the water content and mix proportions to achieve desired concrete workability.