FLYASH INFLYASH IN

GEOTECHNICALGEOTECHNICAL

ENGINEERINGENGINEERINGByBy

NIRANJANNIRANJAN

S. L.N College of Engineering,S. L.N College of Engineering,

Raichur.Raichur.

..

INTRODUCTIONINTRODUCTION FLY ASHFLY ASH PROBLEMS DUE TO FLY ASHPROBLEMS DUE TO FLY ASH GEOTECHNICAL PROPERTIES OF GEOTECHNICAL PROPERTIES OF

FLY ASHFLY ASH PHYSICAL & CHEMICAL PROPERTIESPHYSICAL & CHEMICAL PROPERTIES ENGINEERING PROPERTIESENGINEERING PROPERTIES GEO ENVIRONMENTAL APPLICATIONSGEO ENVIRONMENTAL APPLICATIONS CONCLUSION.CONCLUSION.

This presentation includes:This presentation includes:

ENVIRONMENTAL GEO-TECH: ENVIRONMENTAL GEO-TECH: Environmental Geotechnic is a field in which:Environmental Geotechnic is a field in which:

• InvestigatingInvestigating

• PlanningPlanning

• CharacterisationCharacterisation

• Foreseeing & forecasting Foreseeing & forecasting

• Designing of engineering works to Designing of engineering works to protect the environment.protect the environment.

• Avoiding future environmental problemsAvoiding future environmental problems.

FLY ASH:FLY ASH: Flyash is a waste product from Flyash is a waste product from

thermal power stations. thermal power stations. 100 million tones of flyash is 100 million tones of flyash is

produced as a by-product produced as a by-product annually in India alone.annually in India alone.

The ash generated is disposed The ash generated is disposed off in the vicinity of the plants off in the vicinity of the plants as a waste material covering as a waste material covering several thousand hectares of several thousand hectares of land. land.

PROBLEMS FACED DUE TO FLY ASH:PROBLEMS FACED DUE TO FLY ASH: Fly ash stored affects the ecology of Fly ash stored affects the ecology of

the land, water and air in the region. the land, water and air in the region. Fly ash causes ailments like allergic Fly ash causes ailments like allergic

bronchitis, silicosis, and asthma.bronchitis, silicosis, and asthma. The World Bank has cautioned India The World Bank has cautioned India

that by 2015, disposal of fly ash would that by 2015, disposal of fly ash would require 1000 sq km, in its report on require 1000 sq km, in its report on environmental issues in the power environmental issues in the power sector. sector.

Fly ash contaminates Fly ash contaminates

• surface water surface water

• underground water. underground water. Affects aquatic life. Affects aquatic life. Is harmful for plants. Is harmful for plants. Corrodes exposed metallic structures in its Corrodes exposed metallic structures in its

vicinity. vicinity. Fineness is about 4000-8000 cmFineness is about 4000-8000 cm22/g. /g. Fly ash contains traces of heavy metals.Fly ash contains traces of heavy metals.

PROBLEMS FACED DUE TO FLY ASHPROBLEMS FACED DUE TO FLY ASH

CONTINUED….CONTINUED….

Geotechnical properties of fly ash:Geotechnical properties of fly ash:

Chemical composition.Chemical composition. Specific gravity.Specific gravity. Grain size distribution.Grain size distribution. Atterberg limits. Atterberg limits. Engineering properties.Engineering properties.

CONSTITUENTSCONSTITUENTS PERCENTAGEPERCENTAGE Silica (SioSilica (Sio22))

Alumina (AlAlumina (Al22OO33))

Iron oxide (FeIron oxide (Fe22OO33))

Calcium oxide (CaO)Calcium oxide (CaO)Magnesium oxide Magnesium oxide

(MgO)(MgO)Sulphur (SOSulphur (SO33))

Loss on IgnitionLoss on Ignition

49 - 6749 - 6716 - 2916 - 294 - 104 - 101 - 41 - 4

0.2 - 20.2 - 2

0.1 - 20.1 - 20.4 - 0.60.4 - 0.6

Chemical compositionChemical composition:

Specific Gravity: Specific Gravity: MATERIALMATERIAL SPECIFIC GRAVITYSPECIFIC GRAVITY Bottom ashBottom ashFly ashFly ash

USAUSAIndiaIndia

Pond ashPond ashIndiaIndiaUKUK

PolandPolandSoilsSoils

2.28-2.782.28-2.78  

2.03-2.492.03-2.491.84-2.671.84-2.67

  1.58-2.391.58-2.392.10-2.242.10-2.241.90-2.311.90-2.312.60-2.802.60-2.80

Grain Size DistributionGrain Size DistributionMATERIAL MATERIAL EFFECTIVEFFECTIV

E SIZEE SIZEDD1010 (mm) (mm)

DD5050

(mm(mm))

UNIFORMUNIFORMITYITY

COEFFICICOEFFICIENTENT

COEFFICICOEFFICIENT OFENT OF

CURVATUCURVATURERE

Fly ash Fly ash 0.0027-0.0027-0.020.02

0.036-0.036-0.20.2

13.3-10.013.3-10.0 2.16-2.16-0.730.73

Pond ashPond ash 0.014-0.014-0.0380.038

0.1-0.20.1-0.2 7.1-5.37.1-5.3 1.20-1.20-0.950.95

Bottom Bottom ashash

0.08-0.70.08-0.7 0.46-6.40.46-6.4 5.8-9.15.8-9.1 0.83-0.83-1.031.03

Liquid LimitLiquid Limit Liquid limit is determined by Liquid limit is determined by

cone penetration method. cone penetration method. As per the Unified Classification As per the Unified Classification

system, fly ash will fit into ML system, fly ash will fit into ML group.group.

It is non-plastic in nature.It is non-plastic in nature.

ENGINEERING PROPERTIES:ENGINEERING PROPERTIES:

• Permeability characteristicsPermeability characteristics

• Consolidation and compressibility Consolidation and compressibility characteristicscharacteristics

• Strength characteristics. Strength characteristics. Shear strength parametersShear strength parameters California Bearing RatioCalifornia Bearing Ratio

APPLICATIONS OF FLY ASHAPPLICATIONS OF FLY ASHGeo-technical applicationsGeo-technical applications

• EmbankmentsEmbankments

• Fills Fills

• Sub base and PavementsSub base and Pavements

• StabilizationStabilization

Okhla flyover approach embankment First geogrid reinforced fly ash approach

embankment constructed in the country Length of embankment – 59 m Height varied from 5.9 to 7.8 m Ash utilised – 2,700 cubic metre Opened to traffic in 1996 Performance has been very good

7.8 to 7.8 to 5.9 m5.9 m

Facing Facing panelspanels

Filter Filter mediummedium GeogridsGeogrids

Reinforced foundation mattress of bottom ashReinforced foundation mattress of bottom ash

Okhla flyover approach embankmentOkhla flyover approach embankment

Okhla flyover approach embankmentOkhla flyover approach embankment

Erection of facing panelsErection of facing panels

Rolling of pond ashRolling of pond ash

Support provided to facing Support provided to facing panels during constructionpanels during construction

Laying of geogridsLaying of geogrids

Okhla flyover approach embankmentOkhla flyover approach embankment

Approach embankment for second Approach embankment for second Nizamuddin bridge at DelhiNizamuddin bridge at Delhi

– Length of embankment - 1.8 km Length of embankment - 1.8 km – Height varies from 6 to 9 mHeight varies from 6 to 9 m

– Ash utilised - 1,50,000 cubic metreAsh utilised - 1,50,000 cubic metre

– Embankment opened to traffic in 1998Embankment opened to traffic in 1998– Instrumentation installed in the embankment Instrumentation installed in the embankment

showed very good performanceshowed very good performance– Approximate savings due to usage of fly ash is Approximate savings due to usage of fly ash is

about Rs.1.00 Croreabout Rs.1.00 Crore

Spreading of pond ashSpreading of pond ash

Compaction of pond ashCompaction of pond ash

Second Nizamuddin bridge approach embankmentSecond Nizamuddin bridge approach embankment

Stone pitching for slope Stone pitching for slope protectionprotection

Traffic plying on the Traffic plying on the embankmentembankment

Second Nizamuddin bridge approach embankmentSecond Nizamuddin bridge approach embankment

Stabilization of soil using fly ashStabilization of soil using fly ash

Stabilization:Stabilization:

Field construction using soil stabilized with fly ash:Field construction using soil stabilized with fly ash:

Village road to Nandawala, Haryana.Village road to Nandawala, Haryana.

Ghaziabad bye-pass joining SH and NH.Ghaziabad bye-pass joining SH and NH.

A village road section at Panipat, Haryana.A village road section at Panipat, Haryana.

Construction of base coarse for Container Construction of base coarse for Container Corporation of India’s container yards at Corporation of India’s container yards at Ludiana, Punjab.Ludiana, Punjab.

FillsFills• DMRC (Delhi Metro Rail Corporation) has used fly DMRC (Delhi Metro Rail Corporation) has used fly ash for construction of railway embankments and land ash for construction of railway embankments and land filling. filling.

• The DMRC has used The DMRC has used 950 000 cubic metres950 000 cubic metres of fly of fly ash for filling up land in the Shastri Park in New ash for filling up land in the Shastri Park in New Delhi. Delhi.

Sub base and PavementsSub base and Pavements

Fly ash has been used as sub base and pavements in:Fly ash has been used as sub base and pavements in:

•  Rural roads near Raichur, Karnataka.Rural roads near Raichur, Karnataka.

• Roads at Delhi, Calcutta, Dadri, Ramgundam and Roads at Delhi, Calcutta, Dadri, Ramgundam and VishakapatnamVishakapatnam.. 

Demonstration road project at Raichur

Total length of the road – 1 km Five sections of 200 m each with different

pavement sections Pond ash has been used for replacing

moorum in sub-base course Stabilised pond ash used for replacing

part of WBM layer Performance of all the specifications is

good

Construction of roller Construction of roller compacted concrete compacted concrete pavementpavement

View of the demonstration View of the demonstration road stretch after three yearsroad stretch after three years

Demonstration road project using fly ash at RaichurDemonstration road project using fly ash at Raichur

CONCLUSIONS:CONCLUSIONS:Fly ash is a by product obtain from Fly ash is a by product obtain from

thermal power stations thermal power stations Fly ash pollutes the ecosystem of the Fly ash pollutes the ecosystem of the

area drastically.area drastically. Fly ash poses a lot of health problems Fly ash poses a lot of health problems

in the area. in the area. The storage of fly ash is problematic The storage of fly ash is problematic

and the safe disposal of fly ash is and the safe disposal of fly ash is challenging. challenging.

The September 14, 1999 notification The September 14, 1999 notification issued by MOEF makes mandatory use of issued by MOEF makes mandatory use of 25% flyash within 50 Km radii of thermal 25% flyash within 50 Km radii of thermal power plants for manufacture of bricks, power plants for manufacture of bricks, tiles etc.tiles etc.The quantity of fly ash available is higher The quantity of fly ash available is higher than that being utilised. than that being utilised. The maximum quantity of fly ash can be The maximum quantity of fly ash can be used in geotechnical application.used in geotechnical application.Use of fly ash in various geotechnical Use of fly ash in various geotechnical applications in India is gaining momentumapplications in India is gaining momentum ..

REFRENCES:REFRENCES:

National seminars presented in I I Sc, Bangalore.National seminars presented in I I Sc, Bangalore.

• ““Characterstics of flyash and its applications” by Narasimha Rao Characterstics of flyash and its applications” by Narasimha Rao (1999).(1999).

• ““Flyash as pesticides in agriculture” by Narayanaswamy P (1999)Flyash as pesticides in agriculture” by Narayanaswamy P (1999)

• ““Flyash utilisation in embankment with geogrids and anchor Flyash utilisation in embankment with geogrids and anchor reinforcement” by Singh.R.B, Pallavi Khanna and reinforcement” by Singh.R.B, Pallavi Khanna and Agarwall R.K.(1999) Agarwall R.K.(1999)

• ““Characterisation of flyash in cement based grouts” by Characterisation of flyash in cement based grouts” by Shorff A.V (1999)Shorff A.V (1999)

• ““Utilisation of flyash in construction of base course for Utilisation of flyash in construction of base course for pavements” by Tike.G.K, Satender kumar, seehra S.S, and pavements” by Tike.G.K, Satender kumar, seehra S.S, and sikdar P.K.(1999)sikdar P.K.(1999)

• ““Flyash-A multi facet resource material” by Vimal kumar,Mukesh Flyash-A multi facet resource material” by Vimal kumar,Mukesh Mathur, Chandi Nath Jah and Goutam Goswami.Mathur, Chandi Nath Jah and Goutam Goswami.

Presentation on “Flyash characterisation” by Sridharan A,(2000) in Presentation on “Flyash characterisation” by Sridharan A,(2000) in S.J.C.E Mysore.S.J.C.E Mysore.

THANK YOU.THANK YOU.