Table of Contents
Why do we calculate fineness of cement?
Fineness test is used to change the proper grinding of cement and measures the surface area of the cement particles per unit mass. Therefore finer cement react faster with water and the rate of development of strength and corresponding heat of hydration is high.
Which apparatus is used for fineness?
The Blaine Fineness Apparatus is used in measuring the fineness of Portland cement in accordance with ASTM and AASHTO standards. The fineness is measured in terms of the specific area of cement expressed as total surface area in square centimeters per gram.
What does fineness cement mean?
The fineness of cement is a major factor influencing its rate of hydration since the reactions involved occur at its interface with water. The finer the cement particles and the greater its surface area, the faster is the rate of hydration and the greater is the proportion of the cement which reacts within the paste.
Which sieve used for fineness of cement?
Fineness test on cement can be determined by using 75 microns sieve.
Why fineness test is done?
Fineness test of cement is done to determine the particle size of cement. As, the rule of thumb, the finer the cement particle the best will be the cement and on the other hand the coarser the particle it will not be that good.
How do you calculate fineness modulus?
The Fineness Modulus (FM) is an empirical figure obtained by adding the total percentage of the sample of an aggregate retained on each of a specified series of sieves, and dividing the sum by 100.
Is code for fineness test of cement?
FINENESS OF CEMENT BY DRY SIEVING (IS:4031-Part 1-1996)
How fineness of the cement affects the properties of cement?
Increasing the fineness increases the rate of hydration of cement, which increases the rate of gain in strength and also the rate at which heat is liberated as in Type III compared with Type I cement (ASTM C150).
How do you test fineness?
The Fineness Test of Cement is done by sieving cement sample through standard IS sieve. The weight cement particle whose size greater than 90 microns is determined and the percentage of retained cement particle are calculated. This is known as the Fineness of cement.
Why 90 micron sieve is used in fineness of cement?
The percentage residue left on screen of 90 micron sieve is called Fineness of cement. Same procedure can be adopted for marble powder. Fineness of cement has a great effect on the rate of hydration and hence the rate of gain of strength. Fineness of cement increases the rate of evolution of heat.
What is the fineness modulus of concrete?
The fineness modulus of the sand used in ordinary concrete is within 3.7 ~ 1.6.
How can you tell the fineness of cement?
The Fineness of cement can be Calculated by particle size analysis, by using the air permeability method, by using sedimentation method. To begin with, let’s understand how the size of cement particles affects the hydration of the cement.
How does the fineness of cement affect hydration?
To begin with, let’s understand how the size of cement particles affects the hydration of the cement. Size of Particles – If the size of a particle is small i.e. fineness is high then the hydration process will be fast. Let’s understand this by considering two cement particles of different sizes i.e. large particle and small particle.
How is the Fineness modulus of cement determined?
The Fineness modulus of cement is an empirical figure obtained by adding the total percentage of the sample of an aggregate retained on each of a specified series of sieves, and dividing the sum by 100. The proportion of cement of which the grain sizes are larger than the specified mesh size is thus determined. 90µm Sieve.
How does fineness of cement affect workability?
A.: The fineness of cement usually affects the rate at which cement gains strength. It may also have a minor effect on workability but probably not much. If you took a cement and ground part of it to a greater fineness the finer portion would produce higher early strength than the other portion.