IS 8112:1989 is the Indian Standard (BIS) for ordinary portland cement, 43 grade - specification. This standard lays down the manufacturing, chemical, and physical requirements for 43 Grade Ordinary Portland Cement (OPC). It is a general-purpose cement whose 28-day compressive strength is specified to be a minimum of 43 MPa. The code provides mandatory requirements for properties like setting time, soundness, and fineness, along with guidelines for storage and marking.
Specifies requirements for 43 grade ordinary portland cement; commonly referenced for older projects.
IS 8112 specifies Ordinary Portland Cement, 43 Grade — the workhorse cement for general structural concrete in India. If your mix design targets characteristic strength M20 to M40 with normal exposure, this is the cement your batching plant is calling for.
43 Grade means the 28-day compressive strength of standard mortar cubes ≥ 43 MPa (1:3 cement:standard sand by mass, w/c 0.4, vibrated). The grade number is *cement strength* — not concrete strength. M30 concrete made with OPC 43 typically gets there at w/c ≈ 0.43 with proper aggregate gradation.
Use IS 8112 cement when: - General RCC for residential, commercial, infrastructure (M20-M40) - Precast elements where 28-day strength matters more than early strength - Pump-mix concrete where 1-day strength of OPC 53 would risk early stiffening
Don't use it when IS 269 (33 Grade, low-heat applications), IS 12269 (53 Grade, high-strength precast / fast-cycle), or PPC (IS 1489) is more appropriate.
Compressive strength (mortar cubes, 1:3 cement:standard sand, w/c 0.4): - 3-day: ≥ 23 MPa - 7-day: ≥ 33 MPa - 28-day: ≥ 43 MPa
Fineness: specific surface ≥ 225 m²/kg (Blaine). Most modern OPC 43 runs 280-340 m²/kg.
Setting time (Vicat apparatus): - Initial: ≥ 30 minutes - Final: ≤ 600 minutes (10 hours)
Soundness: - Le Chatelier expansion: ≤ 10 mm - Autoclave expansion: ≤ 0.8 %
Chemical composition limits: - MgO: ≤ 6.0 % - SO₃: ≤ 3.5 % (when C₃A ≤ 5 %); ≤ 3.0 % (when C₃A > 5 %) - Loss on ignition: ≤ 5.0 % - Insoluble residue: ≤ 4.0 % - Alkali content (Na₂O equivalent): ≤ 0.6 % when reactive aggregates are present (refer IS 383 for AAR screening)
1. Confusing 43 (cement grade) with M43 (concrete grade). There is no M43. Cement grade ≠ concrete grade. Mix design with OPC 43 is what you do to *achieve* M20-M40 concrete. 2. Using OPC 43 when PPC was specified. PPC (IS 1489) has fly ash/slag — different early strength curve, lower heat, better sulphate resistance. Substituting affects mix design and durability assumptions in IS 456 Clause 8. 3. Expecting 53 Grade performance from 43 Grade. OPC 53 hits 53 MPa cube strength at 28d but also has higher early-age heat and faster setting — relevant for hot weather concreting (cooler concrete = less thermal cracking — see IS 7861). 4. Ignoring storage life. Cement loses strength on storage: ~10 % at 1 month, ~20 % at 3 months, ~30 % at 6 months in tropical humidity. Specify FIFO at site stores. IS 8112 acceptance is at delivery, not at use. 5. Not screening for high alkalis when aggregates are reactive. The 0.6 % Na₂O equivalent ceiling is only enforced when IS 383 AAR test on the aggregates flags reactivity.
Per IS 456:2000 Clause 6.1.2 and IS 4905, sampling frequency for cement at site: - One composite sample per 100 t for routine works (or per consignment if smaller) - For critical works (Class A bridges, water-retaining structures, high-strength M50+): every 50 t - One sample = 1 kg drawn from 12 random bags / 12 random points in a silo, cone-and-quartered
A delivery is acceptable if cube strength at 28 days meets the 3-result rolling mean ≥ 43 MPa AND no individual result < 38 MPa (Clause 11 acceptance criteria). 7-day strength is for early indication; rejection only on 28-day fail.
If 28-day fails, the cement may still be usable for non-structural fill/blinding — get the structural engineer's specific written approval before incorporating into RCC.
IS 8112:1989 was reaffirmed multiple times. Notable amendments: - Amendment 1 (1991): alkali ceiling clarified; AAR screening linkage to IS 383. - Amendment 2 (2003): SO₃ limits split by C₃A content (the 3.5 % vs 3.0 % rule). - 2013 revision in IS 269:2015 consolidates 33 + 43 + 53 grade into one document — IS 8112 itself was not formally withdrawn but most procurement now references IS 269:2015. Treat them as interchangeable for the 43 Grade clauses; if the contract specifies one, deliver against that one.
For design and mix design (IS 10262:2019), the difference is invisible — the *cement grade* enters the same target mean strength equation.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| 28-Day Compressive Strength (Min) | 43 MPa | 42.5 MPa | EN 197-1:2011 (Class 42,5 N) |
| 7-Day Compressive Strength (Min) | 33 MPa | 19 MPa | ASTM C150 / C150M - 22 (Type I) |
| Initial Setting Time (Min) | 30 minutes | ≥ 60 minutes | EN 197-1:2011 |
| Final Setting Time (Max) | 600 minutes | Not specified (performance-based) | EN 197-1:2011 |
| Soundness (Le Chatelier Expansion, Max) | 10 mm | 10 mm | EN 197-1:2011 |
| Magnesia (MgO) Content (Max) | 6.0% | 5.0% | EN 197-1:2011 |
| Sulphuric Anhydride (SO3) Content (Max) | 3.0% (if C3A > 5%) | 3.5% | EN 197-1:2011 (For CEM I) |