Specific Gravity Of Cement | Specific Gravity Test On Cement
Hello friends, today in this post you will learn the Specific Gravity Test on Cement with calculations & detail stepwise procedure.
So, don't skip to read the post completely. After reading the post, you will completely understand the simple tests of the Compression test on concrete cubes.
So, let's start with these amazing topic...
What is the mean by Specific Gravity of Cement
It may be is defined as the mass of cement of a specified volume to the mass of water of the same volume of cement.
In another words, it may also be defined as the density of cement to the density of water for the same volume.
In above both definitions, the volume of cement must be the same. If the volume does not remain the same then the specific gravity value may be accurate.
The main reason behind is that the mass & density of cement as well as the water are liable to change with respect to their volume.
In Specific gravity, we compare the mass or density of any substance with the mass or density of the standard substance. Generally, we consider water as the standard substance.
The best method to determine the specific gravity of cement is by using a liquid such as water-free kerosene, which does not react with cement.
For conducting Specific gravity test, we use standard Le Chatelier specific gravity flask or specific gravity bottle.
These Le Chatelier specific gravity flask can also be used to determine the specific gravity of dust, sand & other fine materials.
This specific gravity of cement is an considerd very important parameter in concrete mix design material quantity calculations.
This specific gravity of Portland cement is about 3.15 and can be measured using ASTM C188.
Use of Cement Specific Gravity
The specific gravity value of any substance gives the idea of how heavy or light is the substance compared to the standard substance.
From the value, we can judge whether it will float or sink into another substance.
All naturally available material & substance have their own specific gravity value. It generally ranges from 1-100.
Water having a specific gravity of around 1 & If the specific gravity of other material is greater than 1, then it sinks in water.
If the specific gravity of the material is less than 1 it floats in water.
Therefore, the specific gravity of any material is an important property. So that we can use it in a proper way.
Generally, the specific gravity of cement ranges between 3.1 to 3.16 g/cc. From this, we can say that the specific gravity of cement is more than the specific gravity of water is 1.
It means cement will sink in water if we put it in the water. Also, we can say that cement is heavier than water.
While we are calculating cement for mix design, we consider the specific gravity of cement as standard 3.14.
If there is any variation in cement-specific gravity, these will affect the mix design.
Therefore, it is necessary to test the specific gravity of the cement procured before the mixing done.
Due to these reason behind, the old stored cement get rejected to use. Old cement has more liable to store external moisture which results in increased specific gravity of cement.
I.S code for Specific Gravity of Cement Test
IS code for the Specific gravity test is IS 2720- Part 3
Apparatus
The following apparatus is used in specific gravity tests of cement :
- Le Chaterlier”s flask
- Weighing balance
- Kerosene (free from water).
Specific Gravity of Cement Procedure
- Before perfoming test, we have to Clean the Le-chatlier flask before use. It should be free from moisture.
- After that we have to, Take the weight of the empty flask as W1.
- Take around 50 gm of cement & fill in the flask.
- Fix the stopper on the flask & weigh the flask with cement as W2.
- After that we have to fill the kerosene in the flask up to the neck of the bottle.
- In these step, we have to mix cement & kerosene in the flask taking care no air bubble is left in it. Then, we have to Record this weight as W3.
- Atlast, we have to then Empty the flask and clean it well. Now, fill the kerosene in it up to the neck of the bottle and record the weight as W4.
Observations and Calculations
The specific gravity of the cement formula is as follows,
= (W2 – W1) / ((W2 – W1) – (W3 – W4) X 0.79)
Where,
W1 = Weight of Empty Flask.
W2 = Weight of Flask + Cement.
W3 = Weight of Flask + Cement + Kerosene.
W4 = Weight of Flask + Kerosene.
Here, the specific gravity of kerosene is 0.79g/cc.
Note :
Conduct tests at least 3 times for accurate results.
Clean the flask before using it again.
Result
The specific gravity of a sample of cement = 3.15
FAQS:
1. What is the Specific Gravity of Cement?
It may be defined as the mass of cement of a specified volume to the mass of water of the same volume of cement. Specific gravity of OPC cement is 3.15.
2. Why specific gravity test is done?
The specific gravity value of any substance gives the idea of how heavy or light is the substance compared to the standard substance. From the Specific gravity value, we can judge whether it will float or sink into another substance.
3. What is the Standard-Specific Gravity of Cement?
Generally, the specific gravity of cement ranges from 3.1 to 3.16 g/cc.
4. What is the use of specific gravity of cement?
Cement particle has pore in them and they can absorb moisture from the atmosphere. Considering this behavior of cement particles the specific gravity can either increase or decrease. While we are calculating cement for mix design we consider the specific gravity of cement as standard 3.14. So, any change in specific gravity will affect the mix design. Hence, it is necessary to perform the specific gravity of the cement procured before the mixing process.
5. What is Specific Gravity of Kerosene ?
The specific gravity of kerosene is 0.79g/cc.
6. Specific Gravity of Cement ?
The specific gravity of cement ranges from 3.1 to 3.15 g/cc.
7. Specific Gravity of OPC ?
The OPC cement specific gravity is 3.1 to 3.16 g/cc which means cement is heavier than water of the same volume & it sinks in water.
8. Specific Gravity of Cement IS Code
IS code for the Specific gravity test of cement is IS 2720- Part 3.
9. Specific Gravity of PPC Cement ?
As per the study, the specific gravity of PPC is found to be 3.06 to 3.08 gm/cm3.
10. Why Kerosene is used for the Specific Gravity Test of Cement?
If we use water instead of kerosene, water will mix with cement & it will result formation of a paste. As we know when cement is mixed with water, cement starts the process of the hydration. So, water can’t be used for cement-specific gravity tests.
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