SOIL STABILISATION USINGBIO-ENZYME EXTRACTED

FROM NEEM

Presented By

Ashokan K & Sreelekha B,M4, Geotechnical Engg,Dept of Civil Engineering.

Guided by

Dr. K BALAN,Professor,

Dept of Civil Engineering.

INTRODUCTION

Mechanical stabilisation

Chemical stabilisation

Standard

Non standard

Enzyme

Stabilization, in a broad sense, incorporates the various methods employed for modifying the properties of a soil to improve its engineering performance.

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STABILISATION USING ENZYME

Enzyme is an organic catalyst that speeds up a chemical reaction.

Natural, Non toxic, non flammable, Non Corrosive liquid enzyme formulation fermented from vegetable extracts.

Demonstrated by the termites and white Ants- Build the shelter by Ant Saliva.

Stabilization is achieved by Microbial process.

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MECHANISM OF SOIL STABILISATION BY ENZYME

Clay Particle –Water Relation

Negative charge on the surface of clay particles attracts positive (Hydrogen) end of water molecule.

Water molecules are arranged in a definite pattern-Adsorbed layer

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Absorbed water in the structure of soil

Elimination of the absorbed water in the soil

Removal of absorbed water by enzyme

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Role of Enzyme;

Catalyze the reaction between the clay and the organic cations and reduces the adsorbed layer thickness.

Replaces adsorbed water with organic cations, thus neutralizing the negative charge on a clay particle.

Promotes the development of cementatious compounds using the following, general reaction:

H2O + clay Enzyme Calcium Silicate Hydrates

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NEED FOR THE PRESENT INVESTIGATION

Recently developed technique.

Can produce from locally available material

Unclear how these product will work and under what

condition.

To better understand their potential value for road

construction.

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OBJECTIVES

To study the quantitative changes in geotechnical properties of

soil with different dosage of enzyme.

To find out the optimum dosage of enzyme.

To evaluate the influence of curing period, on properties of

soil

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MATERIALS USED Soil sample obtained from Karamana river bank

Bio enzyme extracted from Neem

Bio Enzyme Soil sample

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Andrew et al (2003)

USA Conducted laboratory experiment for effectiveness in sub grade.

CBR value is a poor indicator of direct soil strength

Isaac et al (2003)

India Conducted test on lateritic soil and clay type soil in Kerala

Significant increase in CBR ascuring period increases

Manoj et al (2003)

India Six different types of soil with varying clay content

CBR and UCS increased considerably for soils with high clay content

Roger Bergmann(2000)

USA Practical application for roads

Minimum 2% clay content is required for successful stabilisation

LITERATURE REVIEW

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METHODOLOGY

Chemical analysis of bio-enzyme. Chemical analysis of Soil. Particle size analysis of soil. Atterberg limits of soil. Proctor compaction test for untreated soil. Proctor compaction test for soil treated with bio enzyme. CBR test for untreated soils in dry and soaked conditions CBR test for soils treated with bio enzyme in soaked

conditions and after curing period.

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Sl. No.

Property Value

1 Specific gravity 2.61

2 Particle size

Gravel Nil

Sand

Coarse 0.25

Medium 2.90

Fine 57.98

Silt 38.87

Clay Nil

Sl. No.

Property Value

Cu 12.22

Cc 3.64

IS Classification SM

4 Liquid limit 32.0

5 Max. Dry density, g/cc

1.708

6 Opt. moisture content 18.69

7 CBR

Unsoaked 9.74

Soaked 6.21

Geotechnical Properties of soil;

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TEST RESULTS

Clay SiltSand

Fine Medium Coarse

Particle size distribution curve;

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TEST RESULTS … Contd

Liquid limit curve;

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TEST RESULTS … Contd

Chemical composition;a. Soil

Sl No Chemical Constituents Percentage

1 N 1.742 C 3.843 H 10.814 S 0

LocationChemical Constituents

Sulphate(mg/100gm of soil)

Chloride(mg/100gm of soil) Organic matter

Mankattu Kadavu(Top Layer)

1320 35 19

Mankattu Kadavu (Bottom Layer)

1100 30 11

b. Enzyme

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TEST RESULTS … Contd

TEST RESULTSCompaction curve;

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… Contd

Variation of MDD;

TEST RESULTS … Contd

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Variation of OMC;

TEST RESULTS … Contd

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Variation of MDD;

TEST RESULTS … Contd

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Variation of CBR (Soaked);

TEST RESULTS … Contd

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ANALYSIS OF RESULTS Untreated soil;

The soil contains 0.25% coarse, 2.90% medium, 57.98% Fine sand and 38.87% silt & clay. IS classification is SM (silty sand)

The liquid limit of the soil is 32.00%.

For light compaction test, the MDD and OMC are 1.708 gm/cc and 18.69% respectively.

CBR values for unsoaked and soaked condition for light compaction are 9.74% and 6.21%.

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Soil treated with enzyme; The seven different enzyme dosages are used to stabilize the

soil for finding the optimum dosage. Effect on Light Compaction; There is no significant variation in MDD for dosage up to

0.70% and further increase in dosage, MDD values are decreasing.

Effect on CBR; CBR test is conducted with 19% Enzyme dosage for curing

period of one and two weeks under soaked condition. Soaked CBR value after two weeks curing increased by 81%

ANALYSIS OF RESULTS … Contd

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CONCLUSION MDD of the soil sample has been reduced considerably after

increasing the dosage of bioenzyme. This may be due to the soil sample is being sandy soil are less reactive with enzyme.

Reasonable amount of clay content (min. 2%) is essential for better result.

The CBR value under soaked condition has increased by 81% on addition of enzyme and after a curing period of two weeks.

The recommendation of bioenzymes for field use has to be done only after conducting independent laboratory testing.

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REFERENCES

1. Andrew, R.T., Fadi, M.S., Nicholos, E.H. and Elahe, M., (2003), “An Evaluation of Strength change on Sub grade soils stabilized with an Enzyme Catalyst solution using CBR and SSG comparisons”, Geomatrics, Inc. Columbia, Sc 29210, USA.

2. Bergmann, R., (2000), “Soil Stabilizers on Universally Accessible Trials”, Federal Highway Administration, Unites States Department of Transportation.

3. Brazetti, R. and Murphy, S.R., (2000), “General usage of Bio-Enzyme stabilizers in Road Construction in Brazil”, 32nd annual meeting on paving Brazil

4. Hitam, A. and Yusof, A., (1998), “Soil stabilizers for plantation road”, National seminar on Mechanisation in Oil Palm Plantation, Selangor, Malaysia.

5. Isaac, K.P., Biju, P.B. and Veerararagavan, A., (2003), “Soil stabilization using Bio-Enzyme for Rural Roads”, Presented at the IRC Seminar: integrated Development of Rural an Arterial Road Networks for Socio- Economic development, New Delhi.

6. Lacuoture, A. and Gonzalez, H., (1995), “Usage of Organic Enzymes for the stabilization of Natural base soils and sub bases in Bagota”, Pontificia Universidad Jevariana, Faculty of Engineering.

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7. Manoj Shukla, Sunil Bose and Sikdar, P.K., (2003), “Bio-Enzyme for stabilization of soil in Road construction a cost effective approach”, Presented at the IRC Seminar: Integrated Development of Rural and Arterial Road Networks for Socio-Economic development, New Delhi.

8. Mohd Raihan Taha, Tanveer A Khan, Ibtehaj Taha Jawad, Ali Akbar Firoozi and Ali Asghar Foroozi,(2013), “Recent Experimental Studies in Soil Stabilisation with Bio-Enzyme-A Review”, Electronic Journal of Geotechnical Engineer-ing, Vol.18,Bund.R.,pp 3881-3894.

9. Ravi Shankar, A.U., Harsha Kumar, Rai and Ramesha Mithanthaya, I.,(2009), “Bio-enzyme stabilized lateritic soil as a highway material”. Journal of Indian Road Congress, 553, pp 143-151.

10. Shirsavkar,S.S. and Karanne,S.S.,(2010),“Innovation in road construction using natural polymer”, Electronic Journal of Geotechnical Engineer-ing, Vol.15,Bund.O.,pp 1614-1624.

REFERENCES … Contd

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THANK YOU