Cement Flashcards
1
Q
What is cement
A
- Calcium silicate
- Lime
- Silica
2
Q
Cement kiln process
A
- Materials put in a tube
- Machine rotates and reaches 1450 C
- Outputs granules through clinker
3
Q
Cement clinker granules
A
- Output of clinker
- Ground with gypsum to make a powder to be used elsewhere to make cement
4
Q
CSH Gel
A
- Gel sits surrounding the cement grains to increase strength
5
Q
Gypsum
A
- Used in the hydration process to slows down process
- Prevents flash setting
6
Q
Capillary voids
A
- Gaps between grains and CSH gel
- Reduce strength
- Can form canals in the long term
- To avoid you must use finer cement to lower void space
- Lowering W:C ratio can also help reduce voids
7
Q
Ordinary Portland Cement
A
- Normal cement
- No risk of sulphate
8
Q
Modified Portland Cement
A
- Low heat generation required
- Moderate sulphate attack may occour
- Higher risk of heat development
9
Q
Rapid Hardening Portland Cement
A
- Similar to ordinary
- Useful when strength for further construction is needed quickly
10
Q
Low Heat Portland Cement
A
- Used in mass concrete where reduced heat loss is important
11
Q
Sulphate Resisting Portland Cement
A
- Where sulphate resistance is important
