Table of Contents
- 1 Why does black cotton soil swell?
- 2 What are the properties of black cotton soil?
- 3 What is swelling index of soil?
- 4 Why is black cotton soil not suitable for construction?
- 5 What causes the ground to swell?
- 6 What is swelling potential?
- 7 What happens when brick powder is mixed with black cotton soil?
- 8 What is the difference between Ethiopian black cotton soil and Australian soil?
Why does black cotton soil swell?
Black Cotton Soil also consists of the excess of Montmorillonite mineral. Bentonite clay shows swelling and shrinkage characteristics due to moisture content variation due to the presence of Montmorillonite mineral. Bentonite clay is also called Montmorillonite clay.
What are the properties of black cotton soil?
Table 3.1 Geotechnical properties of soil used
| Properties | Black Cotton Soil |
|---|---|
| Maximum Dry Density (kN/m3) | 15.16 |
| Optimum Moisture Content | 21.96 |
| (\%) | |
| Unconfined Compressive Strength(KN/m2) | 84.92 |
Which type of soil has high swelling and shrinkage property?
Shrinking and swelling are generally associated with fine-grained clay soils.
Which clay minerals causes alternate swelling and shrinkage in black cotton soil?
The black cotton soils contain the Montmorillonite as a clay mineral, which causes the swelling nature in soil, due to water bond between the particles of soil. In India, the black cotton soil is available in about 20 – 25\% land area, which includes major portion of Madhya Pradesh and Andhra Pradesh of India.
What is swelling index of soil?
DEFINITION • Free Swell Index is the increase in volume of a soil, without any external constraints, on submergence in water.
Why is black cotton soil not suitable for construction?
The shrinkage and swelling of black cotton soil has become a severe problem for the entire construction industry. The swelling and shrinkage of expansive soil cause the differential settlement of building. When dry, it is very hard, but it loses strength completely when wet.
What are the disadvantages of black soil?
Besides advantages of black soil, there are some disadvantages or problems of black soil. Those are listed below. Cracking when dry and swelling when wet makes them difficult to manage, unless they are cultivated at appropriate soil moisture levels. This makes black soil difficult to manage.
Are commonly used in black cotton soils which swell and shrink to a greater extent when in contact with water?
Black cotton soils are clayey(> 35\% clay) and are dominated by expanding clay minerals like smectites that cause enormous shrink-swell properties.
What causes the ground to swell?
Issues Surrounding Your Home. Shrink swell soil is the movement caused by the amount of water in the soil. A lot of rain or a very dry season can change how your soil acts around your foundation. When your area experiences a lot of rain, the soil will swell and expand.
What is swelling potential?
Shrink/swell potential is the relative change in volume to be expected with changes in moisture content, that is, the extent to which the soil shrinks as it dries out or swells when it gets wet. …
What is swelling pressure of soil?
The pressure which the expansive soil exerts , if it is not allowed to swell or the volume change of the soil is arrested , is known as Swelling Pressure of Soil. For any clay to be classified as “CNS (non-swelling clay)”, it should not have swell pressure more than the specified value (normally 0.5 kg/m2).
What is black cotton soil and how is it stabilised?
Black cotton soil is one of the major soil deposits of India. They exhibit high swelling and shrinking when exposed to changes in moisture content and hence have been found to be most troublesome from engineering considerations. Stabilization occurs when lime is added to black cotton soil and a pozzolanic reaction takes place.
What happens when brick powder is mixed with black cotton soil?
And the reaction between soil and lime forms more strength resistance. When the brick powder is mixed with black cotton soil, the strength of the soil increases significantly. Brick powder with bagasse ash when mixed with black cotton soil improves the unconfined compressive strength of soil gradually.
What is the difference between Ethiopian black cotton soil and Australian soil?
According to Khanna in 1966 and also confirmed by Virgo in 1969, Rathore and Chatterjee in 1976, Ethiopian black cotton soils also have dominant faction of montmorillonite in clay minerals; so does in Indian black cotton soils. But in Australia there have domination of kaolinite or illite.
Is lime suitable for black cotton soil?
So the suitability of lime is considered to enhance the properties of black cotton soil.