About this code
Specification for 43-grade OPC, the workhorse cement for general RCC construction. Defines chemical, physical, and testing requirements.
Key sections
- 01Scope and references
- 02Chemical composition
- 03Physical requirements
- 04Sampling and testing
- 05Packing and marking
Critical clauses
Clause 6.1Compressive Strength
Min 23/33/43 MPa at 3/7/28 days.
In practiceMost common cement for M20-M40 RCC.
Clause 6.2Setting Time
Initial >= 30 min, Final <= 600 min.
In practiceAdequate for normal placement.
Clause 6.3Fineness
Min 225 m2/kg.
In practiceHigher Blaine = faster strength gain.
Practical implications
For specifiers
Default for M20-M40 RCC.
For suppliers
Most plants stock by default.
For executors
Verify grade marking on each bag.
FAQs
OPC 43 vs OPC 53 — which to use?
OPC 43 for M20-M40 general work; OPC 53 for M45+ or fast-track.
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