How fineness affect the quality of cement?

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.

What is meant by the fineness of cement?

The fineness of cement is property of cement which indicate the particle size of cement and specific surface area and thus indirectly effect heat of hydration. Fineness of cement affects hydration rate hence the rate of strength gain. 2. Bleeding can be reduced by increasing fineness.

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 affects concrete setting?

A. The major factors affecting the time of setting are cement composition, water-cementitious material ratio (w/cm), temperature, and admixtures. When cement hydrates faster, the time of setting is reduced. Increases in the w/cm result in increased time of setting.

What is unit of fineness of cement?

The fineness of cement is represented as cm2 / gram i.e Area/mass. The fineness of cement is measured by sieving it on the standard sieve. The proportion of cement of which the grain sizes are larger than the specified mesh size is thus determined.

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.

What is cement fineness?

The fineness of cement is a measure of the size of particles of cement and is expressed in terms of the specific surface area of cement. The fineness of cement is measured as the \% weight retained on a 90µm IS sieve over the total weight of the sample.

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

A. 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).

What are the factors that affect the shrinkage of concrete?

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. However, if excessive bleeding due to coarseness of the cement takes place, a reduction in the drying shrinkage occurs.

How the size of cement particles affects the hydration process?

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 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.