CEMENT TESTS OPC
Cement is tested to ensure it meets quality standards and gives expected strength in concrete or mortar. These tests are classified into field tests and laboratory tests.
Field Tests (Preliminary, On-site)
1. Color: Uniform grey color with a light greenish shade.
2. Feel Test: Smooth when rubbed between fingers (not gritty).
3. Float Test: A small sample should float for a while in water before sinking.
4. Setting Time (Field): Should not set quickly – gives ample time for workability.
Laboratory Tests (IS: 4031 standards)
1. Fineness Test (IS 4031 Part 1)
Purpose: To check particle size.
Method: 90-micron sieve or Blaine's air permeability.
Limit: <10% residue (sieve method).
2. Standard Consistency Test
Purpose: To determine the water required for a paste of standard consistency.
Method: Vicat apparatus.
Result: Usually around 26–33% of water by weight.
3. Initial and Final Setting Time (IS 4031 Part 5)
Initial Setting Time: ≥ 30 minutes
Final Setting Time: ≤ 600 minutes
4. Soundness Test (IS 4031 Part 3)
Purpose: To detect unsoundness due to excess lime or magnesia.
Method: Le Chatelier apparatus.
Limit: Expansion should be ≤ 10 mm.
5. Compressive Strength Test (IS 4031 Part 6)
Purpose: To measure strength after curing.
Test Sample: Cement-sand mortar cubes (1:3 mix).
Size: 70.7 mm cubes
Curing: In water for 3, 7, and 28 days.
Load: Applied in Compression Testing Machine.
OPC Cement Strength (Compressive)
Cement Grade 3 Days (MPa) 7 Days (MPa) 28 Days (MPa)
OPC 33 ≥ 16 ≥ 22 ≥ 33
OPC 43 ≥ 23 ≥ 33 ≥ 43
OPC 53 ≥ 27 ≥ 37 ≥ 53
> Note: 1 MPa = 10.2 kg/cm² approx
* Relevant IS Codes:
IS 269 – Specification for OPC
IS 4031 – Methods of physi
cal tests
IS 650 – Standard sand
IS 12269 – OPC 53 Grade
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