Site Loader

Chemical
stabilization has different way to be used. Material to be
used can be
selected depending on soil type and condition of
construction site. For example, Lime is not good stabilizer for silts, granular
materials and soils with sulphate contents greater than 0.3 percent. Actually,
lime is helpful material for clay-bearing and highly cohesive soil whereas fly
ash is being used for granular or poorly cohesive soil.  Many materials can be used like, lime ,
cement, fly ash and asphalt. That different chemicals can enhance the strength, compressibility, hydraulic conductivity, swelling potential and
volume changing.  

1.1.1       
Soil Stabilization with Lime:

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Lime is a white caustic alkaline substance consisting of calcium oxide
“CaO”, which is obtained by heating limestone and which combines with water
with the production of much heat. It is very effective chemical in modifying
high plastic clayey soil which can be used alone or by mixing it with another
chemical component like cement, fly ash or bitumen. It is used mainly for
stabilizing subgrade.

Lime stabilization will be done by changing
the nature of adsorbed layer and providing pozzolanic action. As a result, the
high plasticity index of the soil will be reduced. Also, the optimum water
content will be increased and decreasing in the maximum compacted density of
the soil. Therefore, less compaction will lead to the maximum compacted
density.

It found that lime can increase the soil strength and durability when
it added to the soil as ( Fig. ) shows. There is an advisable percentage of
lime to gain that good improvement from it, from 5-8% for plastic soil.

1.1.2       
Soil Stabilization with Cement 5:

The soil stabilized with
cement is known as soil cement which done due to cementing action. Cementing is
the result of chemical reactions of cement with siliceous soil during hydration
reaction. There are some factor affecting soil-cement such as nature of soil
content, conditions of mixing, compaction, curing and admixtures used. In
addition, depending on the soil type, the amount of cement will differ as
follow:

Gravels – 5 to 10%         Sands
– 7 to 12% 

 Silts – 12 to 15%,   and       
Clays – 12 – 20%

In general , Cement stabilization give
better strength and improve quality of soil. Other additives can be mixed with
cement to enhance the soil like Lime, calcium chloride, sodium carbonate,
sodium sulphate and fly ash. In fact, the type of cement which used for stabilization
usually is ordinary Portland cement. calculation of required cement amount is
discussed following:

If the layer of soil
having surface area of A (m2), thickness H (cm) and dry density rd (tonnes/m3),
has to be stabilized with p percentage of cement by weight on the basis of dry
soil, cement mixture will be = 100*P/(100+p)

and, the amount of cement required for soil stabilization is given by

Amount of cement required, in tonnes =   

 

1.1.3       
Soil Stabilization with Bitumen:

 

Asphalt is a dark bituminous substance that is found in natural beds
and is also obtained as a residue in petroleum refining and that consists
chiefly of hydrocarbons. Asphalts and tars are bituminous materials which are
used for stabilization of soil. This stabilization method can be defined as the
treatment of naturally occurring neoplastic or moderately plastic soil with
liquid asphalt at normal temperatures to improve the load-bearing qualities of
the soil.

That Bituminous materials can impart cohesion and reduced water absorption
when added to a soil.

 

Post Author: admin

x

Hi!
I'm Lewis!

Would you like to get a custom essay? How about receiving a customized one?

Check it out