Civil Engineering - Building Materials - Discussion

The answer should be all of these because A,B,C, & D all are field test on cement.

1. DATE OF PACKING:
Date of manufacture should be seen on the bag. It is important because the strength of cement reduces with age.

2. COLOUR:
The cement should be uniform in colour. In general the colour of cement is grey with a light greenish shade. The colour of cement gives an indication of excess lime or clay and the degree of burning.

3. RUBBING:
Take a pinch of cement between fingers and rub it. It should feel smooth while rubbing. If it is rough, that means adulteration with sand.

4. HAND INSERTION:
Thrust your hand into the cement bag and it should give cool feeling. It indicates that no hydration reaction is taking place in the bag.

5. FLOAT TEST:
Throw a small quantity of cement in a bucket of water. It should sink and should not float on the surface.

6. SMELL TEST:
Take a pinch of cement and smell it. If the cement contains too much of pounded clay and silt as an adulterant, the paste will give an earthy smell.

7. PRESENCE OF LUMPS:
Open the bag and see that lumps should not be present in the bag. It will ensure that no setting has taken place.

8. SHAPE TEST:
Take 100g of cement and make a stiff paste. Prepare a cake with sharp edges and put on the glass plate. Immerse this plate in water. Observe that the shape shouldn't get disturbed while settling. It should be able to set and attain strength. Cement is capable of setting under water also and that is why it is also called 'Hydraulic Cement'.

I am agree with @Mr. Singh.

At Site:

Open the bag and take a good look at the cement. There should not be any visible lumps. The colour of the cement should normally in greenish grey. Thrust your hand into the cement bag. It must be giving you a cool feeling. There should not be any lump inside.

Take a pinch of cement and feel-between the fingers. It should give a smooth and not a gritty feeling. Take a handful of cement and throw it on a bucket full of water, the particle should float for some time before they sink.

During field test,the cement is said to be good quality if;

(a) The color of cement is uniformly greenish grey.
(b) A handful of cement, thrown into a bucket of water should float for some time before it sinks.
(c) Rubbed in between fingers it feels smooth.
(d) Hand is thrust into a bag of cement it feels cool.

So here the answer will be option (b).

(a) The color of cement is uniformly greenish-grey.

(b) A handful of cement, thrown into a bucket of water should float for some time before it sinks.

(c) Rubbed in between fingers it feels smooth.

(d) A hand is thrust into a bag of cement it feels cool.

Option E is correct because in question the subjected hand is outsider hand with respect to hand inside the cement bag so one hand feel hotter with respect to hand inside the bag.

Which put in a hand the cement should feel cool. Why because cement chemical reaction started it get hard. In this process gives a lot of heat due to chemical action.

Yes option B is the correct answer, because only the option B shows the quality of cement as asked in the question.

I agree with both @Singh and @Ravi.

I agree @Sumith.

Both (B & D) are correct. A good quality cement should settle down when dropped in water & it should not float on surface.

Thrusting is the key word. Which means pushing hand suddenly or abruptly or violently. And sudden pull out. (root word -thrust).

I think B option is correct because it is a physical property of cement when we check the quality of cement in field.