Fineness of cement is property of cement that indicate particle size of cement and specific surface area. and indirectly effect heat of hydration.

Introduction

The fineness of cement is an important property that affects its performance and quality. It refers to the particle size distribution of the cement particles. The fineness of cement is typically determined by sieve analysis, which involves passing the cement through a series of sieves with different mesh sizes. The sieve analysis is conducted using IS (Indian Standard) sieve numbers, which indicate the size of the openings in the sieves.

IS Sieve Number

The correct IS sieve number for determining the fineness of cement is a) 20. The number 20 corresponds to a sieve with openings of 0.85 mm. This sieve size is recommended for testing the fineness of cement according to the Indian Standard specifications.

Sieve Analysis

Sieve analysis is a method used to determine the particle size distribution of a material. In the case of cement, it involves passing a sample of cement through a series of sieves with progressively smaller openings. The sieves are arranged in a stack, with the largest sieve on top and the smallest sieve at the bottom.

Procedure

The sieve analysis for determining the fineness of cement involves the following steps:

1. Weigh a sample of the cement, typically 100 grams.
2. Prepare a stack of sieves, starting with the largest sieve on top and the smallest sieve at the bottom.
3. Place the sample of cement on the top sieve.
4. Cover the stack of sieves with a lid and shake it horizontally and vertically for a fixed duration.
5. After shaking, remove each sieve from the stack and weigh the amount of cement retained on each sieve.
6. Calculate the percentage of cement retained on each sieve by dividing the weight retained by the original sample weight and multiplying by 100.
7. Plot a graph of the percentage of cement retained versus the sieve size.
8. Determine the fineness of cement by analyzing the graph and identifying the sieve size at which 90% of the cement is retained.

Conclusion

In conclusion, the fineness of cement is determined by sieve analysis using IS sieve number 20. This sieve size allows for an accurate assessment of the particle size distribution of the cement. By conducting sieve analysis, the fineness of cement can be evaluated, which is crucial for determining its suitability for various construction applications.