National Seminar on Jute Geo-textiles (CFC/IJSG/21) Project April 01, 2014 Jute Diversification Promotion Centre (JDPC) Ministry of Textiles and Jute Efficacy of Jute Geo-textiles as Sub-grade Reinforcement for Rural Road Construction in Bangladesh Professor Dr. Abdul Jabbar Khan Professor Dr. Abu Siddique Professor Dr. Mohammad Shariful Islam Asgar Hossain Shamima Nasrin Department of Civil Engineering Bangladesh University of Engineering and Technology Dhaka, Bangladesh

Outline of Presentation Introduction Selection of Sites for JGT Applications Physical and Mechanical Properties of JGT Used Soil Conditions of the Selected Sites Field Test Results During Monitoring Stage Concluding Remarks

Introduction Initially, 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 Organization Location Road/River bank/Hill slope Name Selected/ Rejected RHD Keraniganj, Dhaka Turag-Rohitpur-Baurvita Road Selected Savar, Dhaka Keraniganj (Konakhola) – Kholamura Hazratpur Road LGED Kaliganj, Gazipur Kaliganj-Ulukhola - bypass Road Bancharampur, Brahmanbaria Salimbad-Ruposhd Road SWO Rampura, Dhaka Hatirjheel, Begunbari Khal Nasirnagar, Brahmanbaia Nasirnagar G.C – Chaitain G.C Road SWO & LGED Circular Road, Savar Cantonment Shyamnagar, Satkhira Noabenki – Gazerhat – Harihajanhat Road Dumuria, Khulna Kathaltola – Magorkhali Road Dacope, Khulna Kalinagar – Mongla Port Road Narail Lahuria Saibor-Mithapur Bazar Road, Lohagora South Para - Kandapara Rural Road, Bancharampur Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur

CONCEPT OF SUBGRADE REINFORCEMENT Enough deformation is required for geotextile to act as reinforcement, i.e. yielding soil subgrade is needed to mobilise geotextile’s 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?) B x L z qR q0 No of layer of JGT reinforcement N =1 ΔH Load distribution diagram (after Binquet and Lee, 1975)

FORCES IN A GEOTEXTILE LAYER (How strong should a geotextile be?) Vehicle Type Self Weight in Kg Load in Kg Total Weight in Kg Rear Axle Load in Kg Wheel Load in Kg Wheel Load in kN Large Truck 12000 40000 52000 41600 20800 204 ≈ 205 Medium Truck 6000 15000 21000 16800 8400 82.4 ≈ 83 Small truck 3000 9000 7200 3600 35.3 ≈ 36 Large Bus 7000 19000 15200 7600 74.6 ≈ 75 Mini Bus 4000 10000 8000 39.2 ≈ 40

FORCES IN A GEOTEXTILE LAYER (How strong should a geotextile be?) Cu = JGT NOT REQUIRED Tensile stress developed in JGT for mini bus at different depth for different undrained shear strength of soil.

Properties of 627 gsm and 724 gsm Untreated JGT Parameter Test Standard Unit Type of JGT Description of Samples 627 gsm 724 gsm Mass per Unit Area ASTM D3776 gm/m2 629 830 Thickness ASTM D1777 mm 1.79 2.43 AOS, O95 ASTM D4751* µm 300-600 Vertical Permeability (2 kN/m2) at DIN 5396 m/sec *10-3 4.2 2.3 Grab Tensile Strength at 30°C ASTM D4632 N 890/550 1130/730 Grab Tensile Elongation at 30°C % 31/36 27/30 Wide Width Tensile Strength at ASTM D4595 kN/m 25/22 34/27 Wide Width Tensile Elongation at 17/13 10/16 CBR Puncture Resistance at 200 C DIN 54307 3075 4310

Map of Bangladesh Showing Locations of Selected Sites

Laboratory Tests Conducted on Soil Samples Liquid Limit and Plastic Limit Grain size distribution (Wash Sieve analysis and Hydrometer analysis) Standard Compaction CBR on laboratory compacted soil at 3 densities Shrinkage Limit, Linear Shrinkage, Free Swell, Free Swell Index and Swelling potential tests, specially for expansive soils Before Application of JGT: Field CBR During Monitoring Stage: Field CBR Field Density

Length of construc-tion (m) District/Upa-zilla/Union Selected Sites and Monitoring Status Location F/A Length of construc-tion (m) District/Upa-zilla/Union Design JGT Application 1st Stage Monitoring 2nd Stage Monitoring Turag-Rohitpur-Baurvita Road RHD 487 Keraniganj Done Completed Done on 9.03.2012 Done on 28.09.2012 Noabenki–Gazerhat–Harihajanhat Road, Shymnagar LGED 1000 Satkhira Done on 07.06.2013 South Para-Kandapara Rural Road, Bancharampur 700 Brahmanbaria Done on 05.10.2012 Done on 25.05.2013 Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur 450 Done on 17.05.2013 Lahuria Saibor-Mithapur Bazar Road, Lohagora Narail Circular Road, Savar Cantonment Dhaka Done 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, Brahmanbaria Chainage : 1650 m

South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria Chainage : 1650 m

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 : 123 m (Front)

Circular Road, Savar Cantonment Chainage : 3500 m

Circular Road, Savar Cantonment Chainage : 3500 m

Lahuria Saibor-Mithapur Bazar Road, Lohagora, Narail Chainage : 5150 m

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

Summary of Soil Test Results of Six Selected Sites No. of locations for Sample collection % Finer #200 Sieve (0.074 mm) Soil Type Dry Density (kN/m3) 4-Day Soaked CBR (%) Turag-Rohitpur-Baurvita Road, Keraniganj 3 13.9~97.9 Silty Sand 15.60 ~16.91 4.5 ~6.0 Noabenki–Gazerhat–Harihajanhat Road, Shyamnagar, Satkhira 1 99.8 Silty Clay (LL=58, PI=36) 13.65 ~15.07 0.3~1.1 Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria 86.6~95 Clayey silt (LL=41~45, PI=14~16) 15.50~15.69 1.0~8.0 South Para-Kandapara Rural Road, Bancharampur, Brahmanbaria 99.0 Clayey Silt (LL=39~42, PI=13~16) 14.33~15.57 0.5~3.1 Lahuria Saibor-Mithapur Bazar Road, Lohagora, Narail 99.3~99.8 (LL=67~83, PI=37~53) 14.03~14.37 0.4~1.7 Circular Road, Savar Cantonment 2 92.8~95.4 (LL=55~67, PI=37~38 SL=14~15 LS=14~15) 16.22~16.46 0.6~6.0 LL= Liquid Limit, PI = Plasticity Index, SL = Shrinkage Limit, LS = Linear Shrinkage

PROPOSED DESIGN SECTION (without ISG) Turag-Rohitpur-Baurvita Road, Keraniganj PROPOSED DESIGN SECTION (without ISG) SUBGRADE COMPACTION min. 98% STD, SOAKED CBR min. 3%, DCP max. 25mm/BLOW, IF NOT AVAILABLE, 30mm SUB-GRADE, COMPACTED TO min. 98% STD IN TWO LAYERS, SOAKED CBR min. 4%, DCP max. 30mm/BLOW) 1800 mm 3700 mm Treated JGT (724 gsm, 1.0 m wide) 150 mm COMPACTED AGGREGATE-SAND SUB-BASE (SAND: MAX. 50% OF MIX), AGGREGATE ACV max. 32%, COMPACTED IN TWO LAYERS, EACH LAYER SOAKED CBR min. 30%, DCP max. 3.5 mm/BLOW, COMPACTED TO min. 98% MODIFIED. 150 mm COMPACTED WBM BASE, AGGREGATE ACV max.30%, COMPACTED IN TWO LAYERS, EACH LAYERS SOAKED CBR min. 80%, DCP max. 3.5 mm/BLOW, COMPACTED TO min. 98% MODIFIED. 25 mm carpeting 7 mm seal coat

PROPOSED DESIGN SECTIONS (without ISG)

Turag-Rohitpur-Baurvita Road, Keraniganj 1st Stage Monitoring on 9. 03 Chainage Subgrade CBR 85 ft from bridge approach (9+418 m) 21.3 610 ft from bridge approach (9+250 m) 12.6 9+200 m 7.9 9+335 m 7.0 Field CBR of Subgrade before JGT Application = 3.0

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

2nd Stage Monitoring on 28.09.2012 Chainage Subgrade CBR Turag-Rohitpur-Baurvita Road, Keraniganj 2nd Stage Monitoring on 28.09.2012 Chainage Subgrade CBR 237 ft from North edge of main road (9+272 m) (Road with JGT) 18.0 371 ft from North edge of main road (9+313 m) 22.1 465 ft from North edge of main road (9+342 m) (Road without JGT) 14.0 Field CBR of Subgrade before JGT Application = 3.0

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

Turag-Rohitpur-Baurvita Road, Keraniganj OMC = 15.38% Dry Density = 16.37 kN/m3 In Place CBR increased 6 to 7.4 times in 16 Months OMC = 15.38% Dry Density = 16.37 kN/m3

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 PROPOSED DESIGN SECTIONS(with ISG) Section A-A SUBGRADE COMPACTION min. 98% STD, SOAKED CBR min. 4%, DCP max. 30mm/BLOW, IF NOT AVAILABLE, 30mm SUB-GRADE, COMPACTED TO min. 98% STD IN TWO LAYERS, SOAKED CBR min. 4%, DCP max. 30mm/BLOW) 305 mm 3050 mm 125 mm COMPACTED SAND IMPROVED SUB-GRADE, SAND FM min. 0.5, PI VALUE 6,SOAKED CBR min. 8% & DCP max. 22mm/BLOW,COMPACTED TO min. 98% MODIFIED. Untreated JGT (724 gsm, 1.0 m wide) 125 mm COMPACTED SAND IMPROVED SUB-GRADE, SAND FM min. 0.5, PI VALUE<6,SOAKED CBR min. 8% & DCP max. 22mm/BLOW, COMPACTED TO min. 98% MODIFIED. 150 mm COMPACTED AGGREGATE-SAND SUB-BASE (SAND: MAX. 50% OF MIX), AGGREGATE ACV max. 32%, COMPACTED IN TWO LAYERS, EACH LAYER SOAKED CBR min. 30%, DCP max. 3.5 mm/BLOW, COMPACTED TO min. 98% MODIFIED. 150 mm COMPACTED WBM BASE, AGGREGATE ACV max.30%, COMPACTED IN TWO LAYERS, EACH LAYERS SOAKED CBR min. 80%, DCP max. 3.5 mm/BLOW, COMPACTED TO min. 98% MODIFIED. 25 mm carpeting 7 mm seal coat 305mm

South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria

Field CBR of Subgrade before JGT Application = 2.4 South Para- Kandapara Rural Road, Bansarampur, Brahmanbaria 1st Stage Monitoring on 05.10.2012 Chainage Subgrade CBR 2150 m (Road with JGT) 5.5 1650 m 2.1 1450 m (Road without JGT) 2.2 Field CBR of Subgrade before JGT Application = 2.4

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

Field CBR of Subgrade before JGT Application = 2.4 South Para- Kandapara Rural Road, Bansarampur, Brahmanbaria 2nd Stage Monitoring on 23.05.2013 Chainage Subgrade CBR 1840 m (Road with JGT) 8.5 2000 m 7.1 2100 m 10.4 80 m (Road without JGT) 4.8 Field CBR of Subgrade before JGT Application = 2.4

South Para-Kandapara Rural Road, Bansarampur, Brahmanbaria OMC = 21.1% Dry Density = 15.82 kN/m3 OMC = 21.1% Dry Density = 15.82 kN/m3 OMC = 21.1% Dry Density = 15.82 kN/m3 In 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

Field CBR of Subgrade before JGT Application = 3.3 Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria 1st Stage Monitoring on 17.05.2013 Chainage Subgrade CBR 53 m (Road with JGT) 14.0 123 m 11.0 173 m 11.1 Field CBR of Subgrade before JGT Application = 3.3

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

In Place CBR increased 3.4 to 4.2 times in 16 Months Tezkhali-Titas River Ghat-Chandu Mia Bari Road, Bishnurampur, Brahmanbaria OMC = 18.7% Dry Density = 15.59 kN/m3 OMC = 18.7% Dry Density = 15.59 kN/m3 OMC = 18.7% Dry Density = 15.59 kN/m3 In 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 24 April 2017

Circular Road, Savar Cantonment 1st Stage Monitoring on 10.05.2013 Chainage Subgrade CBR 35 m (Road with JGT) 2.7 300 m 3.1 600 m 7.0 Field CBR of Subgrade before JGT Application = 3.6

Circular Road, Savar Cantonment 1st Stage Monitoring on 10.05.2013

Circular Road, Savar Cantonment OMC = 19.6% Dry Density = 16.5 kN/m3 OMC = 19.6% Dry Density = 16.5 kN/m3 OMC = 19.6% Dry Density = 16.5 kN/m3 In 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 24 April 2017

Field CBR of Subgrade before JGT Application = 2.6 Noabenki – Gazerhat – Harihajanhat Road, Shymnagar, Satkhira 1st Stage Monitoring on 07.06.2013 Chainage Sub-grade CBR 6700 m (Road with JGT) 3.6 7100 m 3.9 7500 m 3.4 Field CBR of Subgrade before JGT Application = 2.6

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

Noabenki-Gazerhat-Harihajanhat Road, Shymnagar, Satkhira OMC = 20.1% Dry Density = 15.8 kN/m3 OMC = 20.1% Dry Density = 15.8 kN/m3 OMC = 20.1% Dry Density = 15.8 kN/m3 In Place CBR increased 1.3 to 1.5 times in 6 Months

Laying of JGT at Noabenki-Gazerhat-Harihajanhat Road, Shymnagar, Satkhira 24 April 2017

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

Contribution of Different Components On Subgrade On JGT On ISG Following hypothesis has been proposed by BUET regarding mechanisms involved with increase of CBR value with time: Contribution of different phenomenon Time JGT acts as initial reinforcement Subgrade soil consolidates Dry density of subgrade soil increases due to moisture absorption via lower sand ISG layer and JGT

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.

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