What Is Fineness of Cement
The fineness of cement is a measure of the size of cement particles, and it refers to the surface area of cement particles per unit weight. It is generally measured by sieving the cement through a standard sieve and determining the percentage of cement particles retained on the sieve.
The fineness of cement is an essential parameter that affects the hydration rate, early strength, workability, and durability of concrete. Cement with a higher fineness provides better concrete quality and performance, but it may also result in higher production costs.
The fineness test of cement is done by sieving cement samples through a standard IS sieve. The weight of a cement particle whose size is greater than 90 microns is determined.
Then the percentage of retained cement particles is calculated. This is known as the Fineness of cement.
Different Tests on Cement
The following tests are conducted on cement in the laboratory as follows:
- Fineness Test of Cement
- Consistency Test of Cement
- Setting Time Test of Cement
- Soundness Test of Cement
- Heat of Hydration Test
- Specific Gravity Test of Cement
- Tensile Strength Test
- Chemical Composition Test
significance of cement fineness
The fineness of cement is an important factor that affects the performance of the concrete mix. Fineness refers to the particle size of the cement and is typically measured by the surface area of the cement particles per unit weight. The finer the cement particles, the greater the surface area, and the higher the reactivity of the cement.
Here are some of the reasons why fineness is important for cement
- Early strength development: Finer cement particles hydrate more quickly and contribute to the early strength development of the concrete. This is important in projects where early strength is required, such as in precast concrete applications.
- Workability: Finer cement particles require less water to produce a workable mix, which can result in more cohesive and easier-to-place concrete. This can be important in projects where concrete is being placed in difficult-to-reach areas.
- Durability: Finer cement particles can lead to a more dense and impermeable concrete, which can improve the durability and resistance to water and chemical attacks.
- Heat of hydration: Finer cement particles produce a higher rate of heat of hydration, which can be a concern in large concrete pours, especially in hot weather conditions.
- Cost: Finer cement is generally more expensive due to the higher energy requirements needed to produce it. However, the benefits of using finer cement, such as improved strength, workability, and durability, may offset the higher cost.
How to Conduct the Fineness Test of Cement
To determine the fineness of cement by using a 90 µm IS sieve as per IS: 4031 (Part 1) – 1996.
- 90µm IS Sieve,
- Weight Balance has a capacity of 10 mg to 100 g,
- Nylon or pure bristle brush
Procedure for testing the fineness of cement
- Collect a sample of cement and rub it with your hands. The Fineness test sample should be free of lumps.
- Take 100 gm of cement sample and note its weight as W1.
- Drop 100 gm of cement in a 90 µm sieve and close it with the lid.
- Now, shake the sieve with your hands by agitating the sieve in planetary and linear movements for 15 minutes.
- After that take the weight of the retained cement on the 90 µm sieve as W2. To calculate the fineness of cement formula is given below,
Fineness = (W2/W1) * 100
Then, calculate the percentage of Weight of cement retained on the Sieve.
Repeat this procedure with three different samples of cement and average the values for accurate results.
The calculation of cement’s degree of fineness
The following table provides a comprehensive overview of the value and significance of cement fineness.
|Sr.No.||Weight of Cement |
|Weight Cement Sample |
Retained on 90µm Sieve
|Fineness of Cement|
|1||100 gm||4.65||4.65 %|
|2||100 gm||8.25||8.25 %|
|3||100 gm||7.95||7.95 %|
Result: The standard value of the fineness of cement should have a fineness of less than 10 % or fineness of cement should not be more than 10% as per IS Recommendations.
The size of the sieve used to test the fineness of cement is?
The size of the sieve used to test the fineness test of cement is 90 microns IS Sieve.
What is the value of the fineness of cement?
Generally, Cement used for construction should have a value of fineness of less than 10%.
Why fineness of cement is important?
Cement smaller particles react much quicker than larger particles. A cement particle with a diameter of 1µm will react entirely in 1 day, whereas a particle with a diameter of 10µm takes about 1 month. If a fine cement particle is more in cement then it will be set too quickly and that not feasible on-site to place concrete properly.
fineness of cement
The fineness of cement is a measure of cement particle size and is denoted in terms of the specific surface area of cement. The weight of cement particle whose size is greater than 90 microns is determined and the percentage of retained cement particle are calculated. This is known as the Fineness of cement.
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