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CHAPTER 1 CEMENT - Coggle Diagram
CHAPTER 1 CEMENT
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MORTAR?
mixture of:
1. cement
2. fine aggregates @ sand
3. water to form a paste
CONCRETE?
mixture of:
1. cement
2. sand
3. coarse aggregates
4. water under certain ratio
DEFINITION?
- Cement is a hydraulic binder
- defined as a finely ground inorganic material
- when mixed with water
- forms a paste which sets and hardens by means of hydration reactions and processes
- after hardening retains it's strength and
stability even under water.
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CEMENT HYDRATION
• Hydration is chemical reaction between cement particles and water.
• The features of this reaction are the change in matter the change in energy level and the rate of reaction.
SETTING & HARDENING
SETTING
• The term ‘Setting‘ is used to describe the stiffening of the cement paste.
• Setting of cement refers to changes of cement paste from a fluid to rigid state.
•Setting differs from Hardening of cement.
INITIAL SETTING
• Initial setting is defined as the beginning of the noticeable stiffening in the cement paste.
• It's corresponding to the rapid rise temperature.
• This normally takes about 45-175 minutes.
FINAL SETTING TIME
• This refers to completion of setting which correspond to the peak temperature in the cement paste.
• The stiffening of cement paste increase as the volume of the gel increases and the stage at which this is completed
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• The final hardening process begins.
• It normally takes between 3 to 10 hours for this to happen.
HARDENING
• The term ‘Hardening’ refers to the gain ofstrength of a set cement paste.
• although during setting the cement paste acquires some strength.
TYPES OF CEMENT 
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Hydraulic
Portland
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OPC
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CLASSIFICATION OF
PORTLAND CEMENTS
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TESTING OF
CEMENT
Objective
2. Soundness
(Soundness of the cement paste refers to its ability to retain its volume after setting)
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