The following are the quality tests on cement at construction site:
- Date of packing
- Colour Test
- Presence of lumps
- Temperature Test
- Float Test
- Adulteration Test
- Glass Plate Test
- Strength Test
- Smell Test
1. DATE OF PACKING:
Strength of cement reduces with time, so it is very important to check the manufacturing date of cement. Generally the cement should be used before 90 days from the date of manufacturing.
2. COLOUR TEST:
The Colour of cement should be uniform. It should be grey with a light greenish shade. This is not always a reliable test but it gives an indication of excess lime or clay and the degree of burning.
3. PRESENCE OF LUMPS:
Cement should be free from hard lumps. Lumps are formed by the moisture absorption from the atmosphere. Any bag of cement containing lumps should not be used for construction work.
4. TEMPERATURE TEST:
If hand is inserted in a bag or heap of cement, it should feel cool not warm. It indicates that no hydration reaction is taking place inside the cement bag.
5. FLOAT TEST:
If a small quantity of cement is thrown in a bucket of water, it should be sink and should not float on the surface.
6. ADULTERATION TEST:
Take a pinch of cement between fingers and rub it, it should feel smooth. If it is felt rough it indicates adulteration with sand.
7. GLASS PLATE TEST:
A thick paste of cement with water is made on a piece of thick glass plate and it is kept under water for 24 hour. It should set and not cracks.
8. STRENGTH TEST:
A block of cement 25 x 25 mm and 200 mm long is prepared and it is immersed in water for 7 days. It is then placed on supports 150 mm apart and it is loaded with a weight of 340 N. The block should not show any signs of failure, the cement is of good quality.
9. SMELL TEST:
A thin paste of cement with water should feel sticky between fingers. If the cement contain too much of pounded clay and silt as an adulteration the paste will give an earthy smell.
