Sampling & Acceptance Chain (IS 3535 → IS 4031 / IS 4032)
An IS 269 acceptance is only valid as a chain: define the lot, draw a representative composite sample per IS 3535, run the physical (IS 4031) and chemical (IS 4032) tests with the standardised sand (IS 650) and consistency-set water (IS 4031 Part 3), then accept or reject the LOT. Cement's defect propagates into every pour, so a non-representative sample certifies nothing.
Key Requirements
•Define the lot (type/grade/source/dispatch); sample representatively per IS 3535 (random across the stack/bulk)
•Seal sample airtight immediately (cement carbonates/absorbs moisture in hours) and test promptly
•Run IS 4031 physical (with IS 650 sand, IS 4031 Part 3 consistency water) + IS 4032 chemical
•Judge the LOT against the IS 269 chemical and physical requirements; accept/reject the lot
•Re-sample per consignment — a later sub-standard delivery is invisible without it
Practical Notes
✓Disputed cement results very often unwind to the sample — convenience-drawn or moisture-degraded — not the cement or the test.
✓Witness the sampling: if the engineer doesn't, the 'representative' sample is whatever was easiest to grab.
Common Mistakes
⚠Bag-tag / convenience acceptance instead of a representative IS 3535 sample.