Скачать или смотреть Compressive strength test for AAC Block | 100mmX100mm size | Lab test |

Here’s a detailed explanation of AAC (Autoclaved Aerated Concrete) block tests as per relevant IS codes, especially IS 2185 (Part 3): 1984 and IS 6441 (Part 1 & 2).

🧱 AAC BLOCK TESTING – As per IS Codes

📘 Applicable IS Codes:
• IS 2185 (Part 3): 1984 – Concrete masonry units – Part 3: Autoclaved cellular (Aerated) concrete blocks
• IS 6441 (Part 1 & 2) – Methods of test for autoclaved cellular concrete products
• IS 3495 (Part 1 to 4) – For compressive strength, water absorption, etc.
(used for comparison purposes with solid blocks)


✅ 1. Dimensions and Visual Inspection

🔍 Purpose:

Check block size, squareness, and appearance

📏 Test Procedure:
• Measure length, width, height using a steel scale or Vernier caliper.
• Test minimum 20 blocks per lot.
• Tolerance as per IS 2185 Part 3:
• Length: ±5 mm
• Width & Height: ±3 mm


✅ 2. Dry Density Test

📦 Purpose:

Check if block density is within limits (lightweight property)

🔬 Test Procedure:
1. Oven-dry the block at 100–115°C for 24 hours
2. Cool in desiccator and weigh (W)
3. Measure volume (L×B×H)
4. Calculate Dry Density = W / Volume

📊 Typical Values:
• Dry Density: 550 to 800 kg/m³ (as per IS 2185 Part 3)


✅ 3. Compressive Strength Test

🧱 Purpose:

Check block strength under load

🧪 Test Procedure (IS 6441 Part 2):
1. Place block in CTM (Compression Testing Machine)
2. Load at 0.5 N/mm²/sec until failure
3. Take average of 3 specimens

📊 Minimum Required Strength:

Grade of AAC Compressive Strength (MPa)
Grade 1 2.5 MPa
Grade 2 3.5 MPa
Grade 3 5.0 MPa


✅ 4. Moisture Content Test

💧 Purpose:

Check residual moisture which affects bonding and plastering

🧪 Test Procedure:
1. Weigh block (W1)
2. Dry in oven at 100–115°C for 24 hours
3. Re-weigh after drying (W2)
4. Moisture Content = ((W1 – W2) / W2) × 100%


✅ 5. Water Absorption Test

💦 Purpose:

Check absorption capacity which affects performance during rain/plastering

🧪 Test Procedure (Similar to IS 3495 Part 2):
1. Dry the block in oven at 100–115°C
2. Cool and weigh (W1)
3. Immerse in water for 24 hours
4. Take out and weigh again (W2)
5. Water Absorption = ((W2 – W1) / W1) × 100%

📊 Permissible Limit:
• Max 10% by weight (as per IS 2185 Part 3)


✅ 6. Shrinkage Test (Optional)

Purpose:

Check dimensional stability of AAC block

🔬 Test Procedure:
1. Cut specimen strip of size (500mm x 50mm x 50mm)
2. Measure original length (L1)
3. Keep it in ambient condition for 28 days
4. Measure final length (L2)
5. Shrinkage = (L1 – L2) / L1 × 100%

✅ 7. Thermal Conductivity Test

🌡️ Purpose:

Check insulation properties (as AAC is used for thermal comfort)
• Conducted in lab using Heat Flow Meter or Guarded Hot Plate method

✅ 8. Sound Insulation Test (Lab-based)

Used in high-end projects to verify noise insulation properties of AAC blocks
– IS 9901 (Sound insulation tests)

📋 Summary Table of Tests

Test Standard Frequency Acceptance Criteria
Dimensions IS 2185 Part 3 20 blocks Within Tolerance
Dry Density IS 6441 Part 1 3 samples 550–800 kg/m³
Compressive Strength IS 6441 Part 2 3 samples 2.5 to 5 MPa (Grade-based)
Moisture Content IS 6441 Part 1 3 samples Typically 10%
Water Absorption IS 2185 Part 3 3 samples 10%
Shrinkage IS 6441 Part 1 Optional 0.05% (recommended)
Thermal Conductivity Lab test Optional 0.2 W/mK (typical)

📌 Notes for Site Use:
• Always collect samples from random batches
• Use calibrated oven and compression machines
• Store blocks properly before testing (avoid wet surfaces)

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