19/07/2025
Slump Cone Test – Know Your Concrete’s Workability!
This simple yet crucial on-site test tells you how workable your concrete is. Perfect for ensuring quality in slabs, columns, beams, and footings. Learn the right method, measure accurately, and build better!
Slump Cone Test – Stepwise Procedure
1. Apparatus Required
Slump cone (300 mm height, 200 mm base dia, 100 mm top dia)
Tamping rod (16 mm dia, 600 mm length)
Non-absorbent base plate
Measuring scale
Trowel or scoop
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🧪 2. Concrete Sample Preparation
Prepare a fresh concrete mix (no initial setting).
Ensure concrete is homogeneous and mixed properly.
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🪜 3. Cone Placement
Place the slump cone on a clean, level, and non-absorbent surface.
Hold the cone firmly by standing on the footrests (if available).
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🏗️ 4. Filling the Cone (in 3 Layers)
Layer 1: Fill 1/3rd of the cone height.
➤ Tamp 25 times uniformly with the rod.
Layer 2: Fill up to 2/3rd height.
➤ Again, tamp 25 times.
Layer 3: Fill to the top.
➤ Tamp 25 times, ensure concrete slightly overflows.
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🔪 5. Level the Top
Use a trowel to strike off the excess concrete and level the surface flush with the top rim.
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⬇️ 6. Cone Removal
Carefully and vertically lift the cone in 5–10 seconds.
Do not twist or jerk.
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📏 7. Measure Slump
Measure the vertical difference between the top of the cone and the highest point of the slumped concrete using a scale.
This gives the slump value in mm.
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📊 8. Interpret the Result
Slump (mm) Workability Use Case
0–25 Very Low Pavements, roads
25–50 Low Footings, raft
50–100 Medium Beams, slabs, columns
100–175 High Thin sections, congested reinforcements
