National Seminar on Jute Geo-textiles (CFC/IJSG/21) ProjectApril 01, 2014Jute Diversification Promotion Centre (JDPC)Ministry of Textiles and JuteDepartment of Civil EngineeringBangladesh University of Engineering and Technology Dhaka, BangladeshEfficacy of Jute Geo-textiles as Sub-grade Reinforcement for Rural Road Construction in Bangladesh Professor Dr. Abdul Jabbar KhanProfessor Dr. Abu SiddiqueProfessor Dr. Mohammad Shariful IslamAsgar HossainShamima Nasrin

Outline of PresentationIntroductionSelection of Sites for JGT ApplicationsPhysical and Mechanical Properties of JGT UsedSoil Conditions of the Selected SitesField Test Results During Monitoring StageConcluding Remarks

IntroductionInitially, possibility of using JGT in 14 rural road sites situated at various geographic locations with varying soil conditions was explored.Among these six sites were finally selected for the application of JGT.Different grades of JGT were tested in the laboratory.Laboratory tests were conducted on soil samples collected from the selected sites.After application of JGT, the performances of these road sections were evaluated by performing CBR test in the trial section at different periods.Application of JGT has already been completed in the six sites while monitoring is being carried out in five sites at various time periods.

List of The Road Sites Visited and Selected for the Project

OrganizationLocationRoad/River bank/Hill slope NameSelected/RejectedRHDKeraniganj, DhakaTurag-Rohitpur-Baurvita RoadSelectedRHDSavar, DhakaKeraniganj (Konakhola) Kholamura Hazratpur RoadRejectedLGEDKaliganj,GazipurKaliganj-Ulukhola - bypass RoadRejectedLGEDBancharampur,BrahmanbariaSalimbad-Ruposhd RoadRejected

SWORampura, DhakaHatirjheel, Begunbari KhalRejectedLGEDNasirnagar, BrahmanbaiaNasirnagar G.C Chaitain G.C Road RejectedSWO & LGEDSavar, DhakaCircular Road, Savar CantonmentRejectedLGEDShyamnagar, SatkhiraNoabenki Gazerhat Harihajanhat RoadSelectedLGEDDumuria, KhulnaKathaltola Magorkhali Road RejectedLGEDDacope, KhulnaKalinagar Mongla Port RoadRejectedLGEDNarailLahuria Saibor-Mithapur Bazar Road, LohagoraSelectedLGEDBrahmanbariaSouth Para - Kandapara Rural Road, BancharampurSelectedLGEDBrahmanbariaTezkhali-Titas River Ghat-Chandu Mia Bari Road, BishnurampurSelectedSWO & LGEDSavar, DhakaCircular Road, Savar CantonmentSelected

CONCEPT OF SUBGRADE REINFORCEMENTEnough deformation is required for geotextile to act as reinforcement, i.e. yielding soil subgrade is needed to mobilise geotextiles strength

A subgrade of less than 1% soaked CBR or less than 3% un-soaked CBR is recommended (Koerner, 1997)

FORCES IN A GEOTEXTILE LAYER(How strong should a geotextile be?)

FORCES IN A GEOTEXTILE LAYER(How strong should a geotextile be?)

Vehicle TypeSelf Weight in KgLoad in KgTotal Weight in KgRear Axle Load in KgWheel Load in KgWheel Load in kNLarge Truck1200040000520004160020800204 205Medium Truck6000150002100016800840082.4 83Small truck3000600090007200360035.3 36Large Bus7000120001900015200760074.6 75Mini Bus40006000100008000400039.2 40

FORCES IN A GEOTEXTILE LAYER(How strong should a geotextile be?)

Properties of 627 gsm and 724 gsm Untreated JGT

ParameterTest StandardUnitType of JGTDescription of Samples627 gsm724 gsmMass per Unit AreaASTM D3776gm/m2629830ThicknessASTM D1777mm1.792.43AOS, O95ASTM D4751*m300-600300-600Vertical Permeability (2 kN/m2) at DIN 5396m/sec *10-34.22.3Grab Tensile Strength at 30CASTM D4632N890/5501130/730Grab Tensile Elongation at 30CASTM D4632%31/3627/30Wide Width Tensile Strength at ASTM D4595kN/m25/2234/27Wide Width Tensile Elongation at ASTM D4595%17/1310/16CBR Puncture Resistance at 200 CDIN 54307N30754310

Map of Bangladesh Showing Locations of Selected Sites

Laboratory Tests Conducted on Soil Samples Before Application of JGT: Field CBR During Monitoring Stage: Field CBR Field Density

Liquid Limit and Plastic LimitGrain size distribution (Wash Sieve analysis and Hydrometer analysis)Standard CompactionCBR on laboratory compacted soil at 3 densities Shrinkage Limit, Linear Shrinkage, Free Swell, Free Swell Index and Swelling potential tests, specially for expansive soils

Selected Sites and Monitoring Status

LocationF/ALength of construc-tion (m)District/Upa-zilla/UnionDesignJGT Application1st Stage Monitoring2nd Stage MonitoringTurag-Rohitpur-Baurvita RoadRHD487KeraniganjDoneCompletedDone on 9.03.2012Done on 28.09.2012NoabenkiGazerhatHarihajanhat Road, ShymnagarLGED1000SatkhiraDone CompletedDone on 07.06.2013South Para-Kandapara Rural Road, BancharampurLGED700BrahmanbariaDoneCompletedDone on 05.10.2012Done on 25.05.2013Tezkhali-Titas River Ghat-Chandu Mia Bari Road, BishnurampurLGED450BrahmanbariaDoneCompletedDone on 17.05.2013Lahuria Saibor-Mithapur Bazar Road, LohagoraLGED1000NarailDoneCompleted

Circular Road, Savar CantonmentLGED1000DhakaDoneCompletedDone on 10.05.2013

Turag-Ruhitpur-Baorvita Road, Keraniganj

Noabenki Gazerhat Harihajanhat, Shymnagar, Satkhira

Noabenki Gazerhat Harihajanhat, Shymnagar, Satkhira

South Para-Kandapara Rural Road, Bansarampur, BrahmanbariaChainage : 1650 m

Chainage : 1650 mSouth Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

Chainage : 123 m (Front)Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria

Chainage : 123 m (Front)Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria

Chainage : 3500 mCircular Road, Savar Cantonment

Circular Road, Savar CantonmentChainage : 3500 m

Chainage : 5150 mLahuria Saibor-Mithapur Bazar Road, Lohagora, Narail

Chainage : Ch 5150 mLahuria Saibor-Mithapur Bazar Road, Lohagora, Narail

Summary of Soil Test Results of Six Selected SitesLL= Liquid Limit, PI = Plasticity Index, SL = Shrinkage Limit, LS = Linear Shrinkage

SiteNo. of locations for Sample collection % Finer #200 Sieve (0.074 mm)Soil TypeDryDensity(kN/m3)4-DaySoakedCBR(%)Turag-Rohitpur-Baurvita Road, Keraniganj313.9~97.9Silty Sand15.60 ~16.914.5 ~6.0 NoabenkiGazerhatHarihajanhat Road, Shyamnagar, Satkhira199.8Silty Clay(LL=58,PI=36)13.65 ~15.070.3~1.1Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria 386.6~95Clayey silt(LL=41~45,PI=14~16)15.50~15.691.0~8.0South Para-KandaparaRural Road, Bancharampur, Brahmanbaria 399.0Clayey Silt(LL=39~42,PI=13~16)14.33~15.570.5~3.1Lahuria Saibor-Mithapur Bazar Road, Lohagora, Narail 3 99.3~99.8Silty Clay(LL=67~83,PI=37~53)14.03~14.370.4~1.7Circular Road, Savar Cantonment 292.8~95.4Silty Clay(LL=55~67,PI=37~38SL=14~15LS=14~15)16.22~16.460.6~6.0

PROPOSED DESIGN SECTION (without ISG)Turag-Rohitpur-Baurvita Road, Keraniganj

PROPOSED DESIGN SECTIONS (without ISG)

Turag-Rohitpur-Baurvita Road, Keraniganj

1st Stage Monitoring on 9.03.2012

Field CBR of Subgrade before JGT Application = 3.0

ChainageSubgrade CBR85 ft from bridge approach(9+418 m)21.3610 ft from bridge approach(9+250 m)12.69+200 m7.99+335 m7.0

1st Stage Monitoring on 09.03.2012Turag-Rohitpur-Baurvita Road, Keraniganj

2nd Stage Monitoring on 28.09.2012 Turag-Rohitpur-Baurvita Road, KeraniganjField CBR of Subgrade before JGT Application = 3.0

ChainageSubgrade CBR237 ft from North edge of main road (9+272 m)(Road with JGT)18.0371 ft from North edge of main road (9+313 m)(Road with JGT)22.1465 ft from North edge of main road (9+342 m)(Road without JGT)14.0

2nd Stage Monitoring on 28.09.2012Chainage : 465 ft ( 9+342 m) from north edge of road (Road section without JGT)Turag-Rohitpur-Baurvita Road, Keraniganj

Turag-Rohitpur-Baurvita Road, KeraniganjOMC = 15.38%Dry Density = 16.37 kN/m3OMC = 15.38%Dry Density = 16.37 kN/m3In Place CBR increased 6 to 7.4 times in 16 Months

Laying of JGT (treated 724 gsm) at Turag-Rohitpur-Baurvita Road, Keraniganj

Conducting In Place CBR Test at Turag-Rohitpur-Baurvita Road, Keraniganj

PROPOSED DESIGN SECTIONS(with ISG)South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

1st Stage Monitoring on 05.10.2012 South Para- Kandapara Rural Road, Bansarampur, BrahmanbariaField CBR of Subgrade before JGT Application = 2.4

ChainageSubgrade CBR2150 m (Road with JGT)5.51650 m(Road with JGT)2.11450 m(Road without JGT)2.2

Chainage : 1450 m (Road section without JGT)1st Stage Monitoring on 05.10.2012 South Para- Kandapara Rural Road, Bansarampur, BrahmanbariaChainage : 1650 m (Road section with JGT)

2nd Stage Monitoring on 23.05.2013 South Para- Kandapara Rural Road, Bansarampur, BrahmanbariaField CBR of Subgrade before JGT Application = 2.4

ChainageSubgrade CBR1840 m (Road with JGT)8.52000 m(Road with JGT)7.12100 m(Road with JGT)10.480 m(Road without JGT)4.8

OMC = 21.1%Dry Density = 15.82 kN/m3OMC = 21.1%Dry Density = 15.82 kN/m3OMC = 21.1%Dry Density = 15.82 kN/m3South Para-Kandapara Rural Road, Bansarampur, BrahmanbariaIn Place CBR increased 3.5 to 4.3 times in 16 Months

Laying of JGT untreated 724 gsm) at South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

Field CBR Test at South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

1st Stage Monitoring on 17.05.2013 Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria

Field CBR of Subgrade before JGT Application = 3.3

ChainageSubgrade CBR53 m (Road with JGT)14.0123 m(Road with JGT)11.0173 m(Road with JGT)11.1

1st Stage Monitoring on 17.05.2013 Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria

Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, BrahmanbariaOMC = 18.7%Dry Density = 15.59 kN/m3OMC = 18.7%Dry Density = 15.59 kN/m3OMC = 18.7%Dry Density = 15.59 kN/m3In Place CBR increased 3.4 to 4.2 times in 16 Months

Laying of JGT (untreated 724 gsm) at Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria

Performance of Field CBR Test and Field Density Test at Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria**

1st Stage Monitoring on 10.05.2013 Circular Road, Savar Cantonment

Field CBR of Subgrade before JGT Application = 3.6

ChainageSubgrade CBR35 m (Road with JGT)2.7300 m(Road with JGT)3.1600 m(Road with JGT)7.0

1st Stage Monitoring on 10.05.2013 Circular Road, Savar Cantonment

Circular Road, Savar CantonmentOMC = 19.6%Dry Density = 16.5 kN/m3OMC = 19.6%Dry Density = 16.5 kN/m3OMC = 19.6%Dry Density = 16.5 kN/m3In Place CBR increased up to 1.9 times in 6 Months

Laying of JGT (untreated 627 gsm) at Circular Road, Savar Cantonment

Performance of Field CBR Test at Circular Road, Savar Cantonment**

1st Stage Monitoring on 07.06.2013 Noabenki Gazerhat Harihajanhat Road, Shymnagar, Satkhira

Field CBR of Subgrade before JGT Application = 2.6

ChainageSub-grade CBR6700 m (Road with JGT)3.67100 m(Road with JGT)3.97500 m(Road with JGT)3.4

1st Stage Monitoring on 07.06.2013 Noabenki Gazerhat Harihajanhat Road , Shymnagar, Satkhira

Noabenki-Gazerhat-Harihajanhat Road, Shymnagar, SatkhiraOMC = 20.1%Dry Density = 15.8 kN/m3OMC = 20.1%Dry Density = 15.8 kN/m3OMC = 20.1%Dry Density = 15.8 kN/m3In Place CBR increased 1.3 to 1.5 times in 6 Months

Laying of JGT at Noabenki-Gazerhat-Harihajanhat Road, Shymnagar, Satkhira**

Performance of Field CBR Test at Noabenki-Gazerhat-Harihajanhat Road, Shymnagar, Satkhira

Contribution of Different ComponentsFollowing hypothesis has been proposed by BUET regarding mechanisms involved with increase of CBR value with time:

Concluding Remarks

In general, due to use of JGT CBR values of subgrade soil increased with time of JGT application. Depending on soil conditions and time of JGT application, CBR values of the subgrade soil increased about 1.3 to 7.4 times.It appears from the test results that use of JGT in the construction of rural roads in Bangladesh plays a significant role in strengthening the subgrade soil. Both Treated and Untreated JGTs decomposed within one year of implementation.

Thank You

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