Nowadays, cement is a very important material in the construction industry. It is mainly used in masonry and concrete construction. The major portion of a structure’s strength mostly depends on the quality of cement.
But when you buy cement there is a certain possibility of quality variations in cement. That is why it is essential to test the cement to know its quality not only to ensure you’re getting what you paid for but also to forestall the possibility of a structural failure through the use of defective materials.
The main qualifications demanded of cement in civil construction are the strength, permanency of structures and a rate of setting suitable to the demands of the work.
Some tests can be performed on the field to justify the cement quality initially. But if you want to justify the physical properties of cement, you need to run some physical tests in the laboratory.
In this post, I’ll discuss 7 important physical test of cement which are carried out in the laboratory.
7 Physical Test of Cement to Justify Its Quality
The physical tests which are generally performed to determine the acceptability of cement are –
- Fineness Test
- Consistency Test
- Setting time Test
- Soundness Test
- Strength Test
- Heat of Hydration Test
- Specific Gravity Test
1. Fineness Test
Fineness is the mean size of cement grain. It is done to measure the mean size of cement grain.
The finer the cement the surface area for hydration will be large and it increases the strength of cement. But the fineness varies in different types of cement.
One of the Following three methods can be applied to test the fineness of cement-
- Sieve method
- Air Permeability method
- Sedimentation method
2. Consistency Test
This physical test of cement is done to estimate the required water quantity to form a normal consistency cement paste. It is defined as the percentage of water required form the cement paste.
3. Setting Time Test
Cement has two types of setting time – Initial setting time and Final setting time.
Initial setting time is the state of cement mortar or concrete when it starts to become stiffen and unworkable.
Final setting time is the state when cement mortar or concrete has become fully unworkable.
Two methods are used to find the initial and final setting time of cement
- Vicat needle method, and
- Gillmore needle method
4. Soundness Test
The soundness of cement means it doesn’t undergo large volume change after setting. Large changes in volume produce cracks, disintegration, and distortion, ultimately leading to failure. So it is very important to test the soundness of cement.
To test the soundness two methods can be applied.
- Le-Chatelier method
- Autoclave method
5. Strength Test
Cement has two types of strength – compressive strength and tensile strength.
To know the compressive strength and the tensile strength of cement following tests are performed –
- Cement mortar cube test (for compressive strength)
- Briquette test (for tensile strength)
- Split tensile test (for tensile strength)
6. Heat of Hydration Test
Cement produces a large amount of heat during the hydration process. When a large amount of concrete volume is poured the inner temperature is greater than the outer surface of the concrete. Because the outer surface is exposed to the weather. Thus the outer surface shrinks rapidly than the inner surface and tends to produce cracks. That is why it is important to test the heat of hydration of cement.
Following test is performed to know the heat of hydration of cement
- Calorimeter method
7. Specific Gravity Test
The specific gravity of cement is a comparison of the weight of a cement volume to the weight of the same volume of water.
Le-Chaterlier flask is used to test the specific gravity of cement.
Which Physical test do you think is more important to justify the cement quality? Please share in comments below…
Editor’s Note: This post was originally published in May 2017 and has been completely revamped and updated for accuracy and comprehensiveness.