Mell What is the standard consistency of the cement?
The Standard or Normal consistency for Ordinary Portland cement varies between 25-35%. To prepare a mix of cement paste of Standard consistency 25-35% of water is added to cement. To explain in detail Let us assume a standard consistency is 30%.
How does fineness of cement affect the normal consistency of cement?
Increase in fineness of cement is also found to increase the drying shrinkage of concrete. Increase in consistency means increase in water demand to get cement paste of standard consistency while increase in workability means increase in flow ability at the same water/cement ratio.
What is the effect of fineness of cement?
Importance of Cement Fineness The fineness of cement affects hydration rate, and in turn, the strength. Increasing fineness causes an increased rate of hydration, high strength, and high heat generation. Bleeding can be reduced by increasing fineness.
What is the difference between setting and hardening of concrete?
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. The term ‘Hardening’ refers to the gain of strength of a set cement paste, although during setting the cement paste acquires some strength.
What is the importance of the normal consistency of cement?
Meaning the cement is consistent and does not move. Consistency plays a vital role in the determination of compressive strength of concrete or workability test for concrete. A certain quantum of water is necessary to react with cement to make a past with appropriate plasticity.
How is fineness of cement calculated?
Fineness = (W2/W1) * 100
- Then, calculate the percentage of Weight of cement-retained on Sieve.
- Repeat this procedure with three different samples of cement and average the values for accurate results.
Why is normal consistency of cement important?
It is necessary to determine consistency because the amount of water affects the setting time of the cement. So, correct proportion of water to cement is required to be known to achieve proper strength while using cement in structure. This can be found out knowing standard consistency of cement paste.
What are the advantages of cement industry?
The cement industry holds some advantages that can allow it to meet this demand, limit its carbon footprint and participate in the development of the regions where it is established. Cement is cheap, adaptable and in strong demand. It can be manufactured while improving its environmental impact.
Why is the fineness of cement so important?
The fineness represents the particle size of cement. It should not be greater than 90-microns when sieved as per IS standard. Importance of fineness of cement More cement coarse particles affect and reduce the rate of hydration.
Why does the standard consistency of cement vary?
Cement Standard consistency is varies because of weather conditions, temperature, humidity, excessive composition of silica in cement, fineness of cement and we know that cement are provided and made by different companies have some different consistency.
How to test the consistency of Portland cement?
Standard Consistency of an ordinary Portland cement varies between 25-30%. That means we need minimum 25% of water and maximum 30% in volume to make cement paste. Let us do the Lab test, how to find normal or standard cement consistency. All the test should be done at Standard method:
How to test the fineness of cement in India?
Apparatus: For (American Standards) 45 u (u = microns) sieve is used, For (Indian Standards) 90 u (u = microns) sieve is used, Pan, sieve cap and cement. Second, Then add this cement in the 90 u sieve and close the sieve with the cap.