- 1. Introduction
- 2. Manufacturing Process (Simplified Flow)
- 3. Hydration of Cement
- 4. Types of Cement (IS Codes & Applications)
- 5. Key Physical & Chemical Properties
- 6. Tests for Quality Control
- 7. Performance Parameters & Durability Factors
- 8. Troubleshooting & Field Failures
- 9. Durability Testing & Modern Quality Evaluation
- 10. Key IS Codes Summary (Consultant Quick Reference)
- 11. Consultant Takeaways
- Disclaimer
At a glance
- Types, properties, and key IS codes summarized.
- Quick QC checklist and performance parameters.
- Yellow callout below highlights common failures and fixes.
How to use this page
- Use the table of contents to jump to sections.
- Start with Types and Key Properties.
- Review Troubleshooting and Standards before finalizing specs.
1. Introduction
Cement is the primary hydraulic binder used in concrete, mortar, plaster, and grout.
It sets and hardens when mixed with water through a chemical reaction known as hydration, forming a dense, stone-like mass that gives strength and durability to structures.
It was first commercialized as Portland cement in the 19th century, named after its resemblance to Portland stone found in England.
Cement’s performance defines:
- Early and final strength of concrete,
- Setting time and workability,
- Durability against environmental exposures, and
- Compatibility with admixtures and SCMs.
2. Manufacturing Process (Simplified Flow)
Raw Materials:
- Limestone (CaCO₃) – source of calcium
- Clay / Shale – source of silica, alumina, and iron
- Gypsum (CaSO₄·2H₂O) – controls setting
- Minor additives: Iron ore, sand, fly ash (in PPC/PSC)
Process Flow:
Stage | Description | Output |
1. Crushing & Grinding | Raw materials crushed into fine powder | Raw Mix |
2. Mixing & Homogenizing | Corrected in proper proportion | Raw Meal |
3. Clinkerization | Burnt at 1400–1500°C in rotary kiln | Clinker |
4. Cooling | Rapid air cooling to preserve properties | Cooled Clinker |
5. Grinding with Gypsum | Final grinding with ~3–5% gypsum | Finished Cement |
6. Packaging | Stored in silos, packed in bags or bulk | Dispatch |
Main Compounds (Bogue’s Formula)
Compound | Formula | Typical % | Role |
C₃S (Alite) | 3CaO·SiO₂ | 45–60 | Early strength (1–7 days) |
C₂S (Belite) | 2CaO·SiO₂ | 15–30 | Long-term strength (28+ days) |
C₃A | 3CaO·Al₂O₃ | 5–10 | Sets rapidly; sensitive to sulphates |
C₄AF | 4CaO·Al₂O₃·Fe₂O₃ | 6–10 | Affects color, minor contribution |
3. Hydration of Cement
When cement is mixed with water, hydration begins immediately.
This reaction forms Calcium Silicate Hydrate (C–S–H) gel — the real binder of strength — and Calcium Hydroxide (CH).
Hydration Reaction:
C₃S + H₂O → C–S–H + Ca(OH)₂
C₂S + H₂O → C–S–H + Ca(OH)₂ (slower)
Phases of Setting:
- Initial Reaction (minutes): Wetting and heat rise
- Dormant Period (1–2 hrs): Workability window
- Acceleration (2–6 hrs): Initial set
- Steady State (1–24 hrs): Hardening
- Slow Strength Gain (days–months)
4. Types of Cement (IS Codes & Applications)
Type | IS Code | Key Features | Typical Application |
Ordinary Portland Cement (OPC 33/43/53) | IS 269:2015 | Standard cement for RCC works | Buildings, pavements, precast |
Portland Pozzolana Cement (PPC) | IS 1489 (Pt 1):2015 | Fly ash-based, durable, lower heat | Mass concrete, residential |
Portland Slag Cement (PSC) | IS 455:2015 | GGBFS-based, high sulphate resistance | Marine, coastal, foundation |
Rapid Hardening Cement (RHC) | IS 8041:1990 | 3-day strength ≈ 7-day OPC | Precast, fast repairs |
Low Heat Cement (LHC) | IS 12600:1989 | Low hydration heat | Dams, raft foundations |
Sulphate Resistant Cement (SRC) | IS 12330:1988 | For aggressive soils | Sewage, chemical plants |
White Cement | IS 8042:2015 | High brightness | Architectural finishes |
Hydrophobic Cement | IS 8043:1991 | Moisture-resistant storage | Remote projects, silos |
5. Key Physical & Chemical Properties
Property | IS Standard | Typical Value | Impact |
Fineness (Blaine) | IS 4031 (Pt 2) | 300–400 m²/kg | Strength & rate of hydration |
Setting Time | IS 4031 (Pt 5) | Initial ≥30 min, Final ≤600 min | Workability & construction control |
Compressive Strength | IS 4031 (Pt 6) | 33–53 MPa | Structural load capacity |
Soundness | IS 4031 (Pt 3) | ≤10 mm | Dimensional stability |
Consistency | IS 4031 (Pt 4) | 26–33% | Workability range |
Loss on Ignition | IS 4032 | ≤5% | Indirect measure of unburnt materials |
Lime Saturation Factor (LSF) | — | 0.66–1.02 | Strength control |
Insoluble Residue | — | ≤4% | Purity control |
6. Tests for Quality Control
Test | Objective | Frequency | Remarks |
Fineness Test | Measure particle size | Batch | High fineness → rapid set |
Setting Time | Workability window | Each lot | Affected by gypsum |
Compressive Strength | Confirm grade | Every 50 tonnes | Key QC measure |
Soundness | Prevent expansion | Monthly | Critical for storage |
Heat of Hydration | Evaluate LHC suitability | Design phase | Optional |
7. Performance Parameters & Durability Factors
Parameter | Optimum Range | Relevance |
C₃S / C₂S Ratio | 1.5–2.5 | Balance early & long-term strength |
Alkali Content | <0.6% | Reduce efflorescence & ASR |
Free Lime | <2% | Prevent unsoundness |
MgO Content | <6% | Avoid expansion |
Sulphate (SO₃) | 2–3% | Controlled by gypsum addition |
8. Troubleshooting & Field Failures
Troubleshooting and common failures — quick view
- False set vs flash set: remix without water vs add retarder and review gypsum control.
- Low early strength: check fineness, C3S content, and storage age; avoid stale cement.
- Efflorescence and surface dusting: manage alkali content, curing, and carbonation exposure.
- Cracks on finish: ensure controlled W/C, proper curing, and shrinkage‑reducing measures.
- Inconsistent setting: verify admixture compatibility and sulphate balance.
Issue | Observation | Root Cause | Solution |
False Set | Stiffening immediately | Partial gypsum dehydration | Remix without water |
Flash Set | Immediate set | Low gypsum, high C₃A | Retarding admixture |
Low Strength | Cube failure | Under-burnt clinker, excess water | Recheck kiln temperature |
Cracks on Finish | Fine shrinkage | Poor curing | Maintain moisture for 7 days |
Efflorescence | White deposits | Excess lime + moisture | Ensure proper curing & mix balance |
9. Durability Testing & Modern Quality Evaluation
Test | Purpose | Standard |
Rapid Chloride Permeability (RCPT) | Assess permeability | ASTM C1202 |
Sulphate Attack Test | Resistance to sulphates | IS 12330 |
Alkali–Silica Reactivity (ASR) | Check aggregate compatibility | IS 2386 (Pt 7) |
Shrinkage Test | Dimensional stability | IS 4031 (Pt 10) |
XRD / SEM | Microstructure & composition | Lab-based |
10. Key IS Codes Summary (Consultant Quick Reference)
Code | Title |
IS 269:2015 | OPC Specification |
IS 1489:2015 | PPC Specification |
IS 455:2015 | PSC Specification |
IS 8041:1990 | Rapid Hardening Cement |
IS 12330:1988 | Sulphate Resistant Cement |
IS 12600:1989 | Low Heat Cement |
IS 4031 | Methods of Testing Cement |
IS 8112:2013 | 43 Grade Cement |
IS 12269:2013 | 53 Grade Cement |
11. Consultant Takeaways
Select cement based on exposure & structural type, not just strength.
Always test fresh samples – avoid stock older than 90 days.
Ensure compatibility with admixtures and SCMs.
For mass concreting, prefer PPC / LHC over OPC 53.
Control temperature rise, especially in large pours.
Verify manufacturer’s test certificates & IS compliance.
Disclaimer
SpecX is an industry initiative & a neutral resource, compiled from industry references and best practices. It is not brand‑specific. Always cross‑check with project requirements and local codes before finalizing specifications.