BeginnerTopic 7 of 112Civil & Structural
Cement and its types
Portland cement hydrates to bind aggregates; types vary in strength and setting.
In depth
Portland cement is made by burning limestone and clay to clinker and grinding it with gypsum. It hydrates in water to bind aggregates. Types: OPC, rapid-hardening, sulphate-resisting, low-heat and blended (fly ash, slag) cements. Cement production causes ~7% of global CO₂.
Key points
- Main compounds C₃S, C₂S, C₃A, C₄AF
- Setting vs hardening
- Blended cements reduce carbon
ExampleFly-ash cement suits mass concrete because it gives off less heat.
Cement is the binder in concrete, and choosing its type controls setting speed, strength gain and resistance to sulphates.
What is Cement and its types?
Portland cement hydrates to bind aggregates; types vary in strength and setting.
Why is it important to understand cement and its types?
Cement is the binder in concrete, and choosing its type controls setting speed, strength gain and resistance to sulphates.
How does cement set?
It reacts with water in a process called hydration, which forms a hard crystalline gel that binds the aggregates together.
What is the difference between setting and hardening?
Setting is the stiffening of the paste as it begins to solidify, while hardening is the gain of strength over the following days and weeks.
How is Cement and its types used in practice?
Typical applications include specifying sulphate-resistant cement for a foundation in clay soil, choosing a rapid-hardening cement for a precast factory and using a blended cement to reduce heat in a massive pour.
What should I learn before Cement and its types?
Study "Construction materials" first (topic 6 of 112 in Civil & Structural). It covers the groundwork this topic builds on.
What are the key points of Cement and its types?
Main compounds C₃S, C₂S, C₃A, C₄AF. Setting vs hardening. Blended cements reduce carbon.
Can you give an example of Cement and its types?
Fly-ash cement suits mass concrete because it gives off less heat.
What comes after Cement and its types?
The next topic is "Aggregates", which builds directly on this one.
How difficult is Cement and its types?
It is classed as Beginner in Civil & Structural (topic 7 of 112). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.