Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Illite does have low swelling properties compared to Montmorillonite and Vermiculite. However, Kaolinite is the least expansive and most stable of all these groups when wet, meaning it essentially does not swell, while Illite can swell slightly.

In order of swelling capacity:

Montmorillonite (highest swelling).
Vermiculite.
Illite (moderate to low swelling).
Kaolinite (minimal to no swelling).

So, for me, the Kaolinite is the most stable and does not swell noticeably when wet.

Kaolinite has gibbsite sheets with aluminium their centre. Since hydrogen bond is involved it is extremely difficult to separate the layers, therefore kaolinite is stable and water is unable to penetrate b/w the layers hence kaolinite shows no swelling when wetting.

Kaolinite - no swelling ( China clay),
Illite - little swelling,
Montmorillonite - high swelling (B.C Soil).

So answer for given question must be A.

Kaolinite is has less swelling and shrinkage properties because of hydrogen bonding between silica and alumina sheet, while illite has med swelling because of weak vender wall forces between the sheet and montomorolinite has more swelling property because it has small forces between the layer.

Montrorilionite>illite >kaolinite.

Only Answer B is right. Actually Illite is a group of closely related non-expanding clay minerals. Option C and D are directly responsible for swelling. Option A is near to right but B is clearly non-expanding material.

Option A is correct,

Kaolinite is made of 1-1 composition of silica and gibbsite with a strong hydrogen bond due to which water doesn't percolates into it, so it doesn't show any swelling and shrinkage property.

Kaolinite has a low shrink"swell capacity.

Vermiculite medium shrink-swell capacity.

Illite or mite is responsible for the absence of swelling.

Montmori - High swelling.

So answer. B is correct.

Kaolinite a highly stable 1:1 (silica: gibbsite) mineral which is non-swelling with a relatively small surface area, and low adsorptive capacity.

So, the correct answer is Kaolinite.

Kaolinite is very stable group of soil which does not allow any shrinkage and swelling effect. China clay is best example of this group hence correct answer is option "A".

@Mustak Ahmed.

You are wrong, Ionic bond is stronger than hydrogen bond.

Ionic bond>covalent bond>hydrogen bond> dipole-dipole bond> van der wall bond.

In illite_ The space between individual clay crystals is occupied by poorly hydrated potassium cations which are responsible for the absence of swelling.