What this Cement?
🏗️ Introduction
Cement is a binding material used in construction that hardens and sets independently. It's the core material in concrete, mortar, and grout. Without cement, modern buildings, bridges, and roads wouldn't be possible.
What is Cement?
Cement is a fine powder made by calcining limestone and clay minerals in a kiln. When water is added, it forms a paste that sets and hardens over time.
Raw Materials Used in Cement
Limestone (Calcium carbonate - CaCO₃)
Clay (Silica, alumina)
Iron ore
Gypsum (added during grinding)
Sand and shale (optional)
Manufacturing Process (Step-by-Step)
🔹 Step 1: Mining and Crushing
Raw materials like limestone and clay are mined and crushed.
🔹 Step 2: Mixing and Grinding
Crushed materials are blended and ground into a fine powder (called raw meal).
🔹 Step 3: Heating in Kiln (Calcination)
Raw meal is heated at 1400°C–1500°C in a rotary kiln to produce clinker.
🔹 Step 4: Clinker Cooling
The hot clinker is cooled with air.
🔹 Step 5: Grinding with Gypsum
Clinker is ground with gypsum to form the final cement powder.
Cement is packed in bags and sent to construction sites.
Types of Cement
1.OPC (Ordinary Portland Cement)
2.PPC (Portland Pozzolana Cement)
3.PSC (Portland Slag Cement)
4 .White Cement
5.Rapid Hardening Cement
6.Low Heat Cement
7.Sulphate Resistant Cement
Properties of Good Cement
Fine particle size
Proper setting time
High compressive strength
Soundness (no cracks after setting)
Low heat of hydration (for large structures)
Grades of Cement
33 Grade Cement
43 Grade Cement
53 Grade Cement
👉 The number indicates compressive strength in MPa after 28 days.
Tests on Cement
1. Fineness Test
2. Consistency Test
3. Initial and Final Setting Time
4. Compressive Strength Test
5. Soundness Test
6. Heat of Hydration Test
Advantages of Cement
High compressive strength
Quick setting time
Easy to transport and apply
Durable and weather-resistant
Versatile usage in all types of construction
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