IS 269:2015 — Clause Reference

OPC Grades — 33 / 43 / 53 and What 'Grade' Means

IS 269 (current edition) consolidates Ordinary Portland Cement and its grades. The grade number — 33, 43, 53 — is the mi…

Chemical Requirements (LSF, C₃A, MgO, SO₃, IR, Alkali, Chloride)

IS 269 caps the chemical composition that governs cement behaviour: lime saturation factor (LSF) and the alumina/silica …

Physical Requirements — Fineness, Setting Time, Soundness, Strength

IS 269 fixes the physical acceptance: minimum fineness (specific surface, Blaine — IS 4034), initial and final setting t…

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 t…

Storage, Packing & Shelf Life

Cement is perishable: atmospheric moisture and CO₂ cause air-setting, lumping and progressive strength loss in storage. …