What is the effect of fineness on cement?

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.

How does fineness of cement affect the time of setting?

The finer the cement particles are, the larger the total surface area is and the bigger the area contacting with water is. Thus, the hydration will be quick, the setting and hardening will be accelerated correspondingly, and the early strength will be high.

What is the effect of fineness of cement on the cement paste strength?

The strength of cement, especially the early strength significantly increased; heat of hydration increased, the peak of hydration heat brought forward and induction period shortened; porosity of cement paste reduced with the increase of cement fineness.

How does cement fineness affect heat of hydration?

(3) The Impact of Cement’s Fineness The size of cement particles directly affects the hydration, setting and hardening, strength and heat of hydration. Thus, the finer the cement is ground, the more energy will lose and the higher the cost will be.

What is the fineness limit for cement?

Result: The standard value of fineness of cement should have fineness less than 10 \% or fineness of cement should not be more than 10\% as per IS Recommendations.

What is the advantage of fineness?

The fineness of cement has an important bearing on the rate of hydration and hence on the rate of gain of strength and also on the rate of evolution of heat. Finer cement offers a greater surface area for hydration and hence faster the development of strength.

How is fineness of cement expressed?

Concept: Specific surface is expressed as the total surface area in square meters of all the cement particles in one kilogram of cement. The fineness of cement is measured as a specific surface. The higher the specific surface is, the finer cement will be.

How fineness of cement affects Fresh & hard concrete properties?

The 28-day compressive strength of concrete, with or without entrained air, increases with an increase in cement fineness. The fineness of cement influences the drying shrinkage of concrete. When the water content is increased because of fineness, the drying shrinkage is increased.

What is the effect of surface area on cement properties?

The higher specific surface area of POFA indicates a potential increase in pozzolanic reactions, which would enhance the concrete properties mostly in the early stages of hydration [26] . …

How fineness affects hydration rate?

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.

Why fineness test of cement is performed?

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 fineness concrete?

Procedure for finding Fineness test of cement:

1. Take a sample of cement and rub the cement with your hands.
2. Now Take 100g of cement and note it as W1.
3. Pour 100g of cement in 90 µm sieve and close it with the lid.
4. Now place the sieve in Sieve shaking machine for two minutes.

How does the fineness of cement affect the drying shrinkage?

The fineness of cement influences the drying shrinkage of concrete. When the water content is increased because of fineness, the drying shrinkage is increased. However, if excessive bleeding due to coarseness of the cement takes place, a reduction in the drying shrinkage occurs.

What is the fineness of cement?

The fineness of cement is the property of cement that indicates particle size of cement and specific surface area. and indirectly effect heat of hydration.

What are the factors affecting the final strength of cement?

If the size of the cement is small or finely grinned then the initial setting time will be less. The final strength will be the same in both cases. For Example: If the surface area is more than the hydration process is high.

How can we reduce the water requirement of concrete?

Increasing the fineness of cement from 2700 to about 4000 cm2/g reduces the water requirement of concrete. Increasing the fineness of cement beyond an optimum limit increases the water requirement of concrete.