Main topic information
- Practical exercise No.1 Test on the initial and final setting time of gypsum
- Practical exercise No. 2 Vicat apparatus
- Laboratory Practical No. 3 Standard consistency test of cement slurry
- Practical exercise No. 4 Determination of cement setting time
- Practical exercise No. 5 Informative tests on water
1. Visual examination
Equipment: clean transparent container (cup) or test tube
Procedure: Put the water sample in a container and observe against the light. We evaluate the appearance and occurrence of impurities.
- clear, transparent, translucent – suitable
- slightly cloudy, strongly cloudy – unsuitable
- without impurities, with impurities
2. Smell test
Equipment: container or tube with cap
Procedure: Seal the water sample in a container, leave closed for 5 minutes (smell intensifies). Then open and smell.
- faint odour
- strong odour (+ description of the type of odour)
3. pH test
Equipment: litmus paper (pH indicator)
Procedure: Soak the paper in a water sample for 30 seconds.
Evaluation: We compare the paper color to the scale and determine the pH of the sample. Water having a pH = 6-9 is suitable.
4. Test for organic matter
Equipment: container with lid
Procedure: Shake the water sample in the container for 30 seconds.
Evaluation: If the foam disappears within 5 seconds, the water is free of organic substances.
5. Presence of sulphates
Equipment: barium chloride BaCl
Procedure: Add barium chloride solution to water and observe for discoloration.
Evaluation: If the solution turns white or even forms a white precipitate, the water contains a sulfur compound (sulphates) and is not suitable for construction purposes.