What is Specific Gravity of Cement?
Specific gravity of a material is defined as
the ratio between weight of a given volume of material and weight of an equal
volume of water. Therefore, specific gravity of cement is the ratio of weight
of a given volume of cement with weight of an equal volume of water at a
specified temperature.
Why is Specific Gravity Test of Cement Important?
Specific gravity is
an important property of cement being related to its density
and viscosity. It is one of the factor to determine density of cement. If the
specific gravity of cement is more than 3.19 then it has more moisture content,
which will affect the mix and bonding.
Hi friends, you are welcomed in the world of
Civil Allied Gyan. “Read here significance or Importance of specific gravity of cement.”
Also
read:
Significance or Importance of Specific Gravity of Cement:-
- Density of the cement and other material is one of the vital parameter, which determines the design of the concrete. Since concrete mix proposition is done based on the weigh batching not on volumetric so density is most important factor.
- The specific gravity of cement is important because
it is one of the factor which determines the density of the cement.
- As we know that, the cement may contain lots of moisture content if it is exposed to various conditions and humidity.
- We all know that water cement ratio is an important factor of cement paste. It is directly proportional to workability and strength of a bonding. If the cement has already more moisture content in it then, the value of water-cement ratio will actually affect the workability and strength of cement paste rather than increasing it.
- If the specific gravity of cement is more than 3.19 then, the cement is either not minced finely as per the industry standard or it has more moisture (or water) content, which will affect the mix and bonding. This is why you find many chunks while mixing old stock cement for concrete.
- Every material contains solid particles and pores, which may contain moisture content due to extreme weather conditions. Which may rise the specific gravity of material.
- Ones the specific gravity of cement reaches 3.19 then pores are filled with moisture, the chemical reaction take place. This process is called hydration.
- Moisture is the biggest enemy of cement. Once cement hydrated with water, it becomes useless. This is the reason that is why many lumps are formed in the old stock of cement due to moisture content.
- As per Indian Standard Specification, cement is tested for specific gravity if it is older than 3 months.
- Generally, a nominal mix is prepared with the cement of specific gravity value 3.15. If there is any change in this value, it will affect the mix design. It may increase the water-cement ratio, which will affect the workability and strength of concrete.
Read more:
Thanks for reading this article.
Please, don’t forget to share it. |