development of durable jute geotextile for erosion control of river bank dr. s. k. chakrabarti
DESCRIPTION
Development of Durable Jute Geotextile for Erosion control of River bank Dr. S. K. Chakrabarti INDIAN JUTE INDUSTRIES’ RESEARCH ASSOCIATION 17,Taratala Road, Kolkata- 700088. Brief Background. - PowerPoint PPT PresentationTRANSCRIPT
Development of Durable Jute Geotextile for Erosion control of River bank
Dr. S. K. Chakrabarti
INDIAN JUTE INDUSTRIES’ RESEARCH ASSOCIATION17,Taratala Road, Kolkata- 700088
Jute Geotextile (JGT) for its typical functional characteristics and eco-concordance has emerged out as a potential natural Geotextile for many civil engineering applications
For commercial exploitation of Jute Geotextile in addressing various geotechnical issues, there is a need to improve its end use specific functional properties
River bank erosion being a recurrent problem in our country demands appropriate measures for its prevention wherein Jute Geotextile can be used with minimum adverse impact
Existing practices of use copper and bitumen based compounds for enhancing life seems to be inadequate both technically and environmentally
For wider acceptance of JGT in erosion control of river bank comprehensive durability of woven JGT under combined soil and water ambience has to be ensured by an ALTERNATE ROUTE.
Brief Background
Woven Jute Geotextile
Weight - 627 gsm Width : 1.0 - 1.5 metreEnds x Picks : 85x32/dm Tensile strength (kN/m), MD x CD: 20 x 20 AOS (micron) O95 : 150 – 400µ
(Designed and developed by IJIRA- NJB)
Specification of woven Jute Geotextile
A. Organic Biocide: Isothiazolinone derivative B. Water Repellent Compound: Fluorocarbon
derivativeC. Wet pick up : 80-90%D. Drying : 100ºCE. Curing : 120-130ºC
Pad –Dry –Cure Method
Development of durable woven Jute Geotextile
Fabric
Padding Mangle
Trough (Bath)
Drying zone Curing zone
Water repellency of specially treated Jute Geotextile has been measured by Spray Test Method : As per IS 390-1975, R.A in 2003 ,Cone Test: IS 7941: 1976, R.A in 2004, Bundesmann Test: ISO 9865: 1991
Spray test method Untreated JGT Specially Treated JGT
Durable JGT : 90% water repellent
Water Repellency of Specially Treated woven Jute Geotextile
Sr. No. Woven Jute Geotextile % Retention in Strength
( Under enriched soil after 21 days)1. Untreated JGT 17.0
2. Specially Treated JGT 88.0
Soil Burial Test : As per IS: 1623, 1992
Durability of woven Jute Geotextile under soil
Sl. No.
Test Parameters Untreated JGT Fabric
(Control)
Specially treated JGT
Fabric (Experimental)
ASTM / IS Standard
1 Weight (g/m2) at 20% MR 631.7 638.4 D 5261 – 1996
2 Ends x Picks /dm 86.0 X 31.4 85 X 32 IS: 1963 – 1981
3 Tensile strength (kN/m) / Elongation at break (%)
MD CD
24.39 ( 7.08 )20.59 ( 8.04 )
22.25 ( 7.14 )19.74 ( 8.16 )
D 4595 – 94
4 Permittivity at 50 mm constant water head per sec
0.50 0.43 D 4491 – 99a
5 Apparent Opening Size(μm) (O95) 251 234 D 4751 – 99a
6 Rod Puncture Resistance(N) 386.3 373.8 D 4833 – 2000
7 Water Repellency (%) 0.0 90.0 IS: 390-1975
8 % Retention in Strength (Under enriched soil after 21 days)
17.0 88.0 IS: 1623, 1992
Characteristics of specially treated durable woven Jute Geotextile
Durability of both untreated and specially treated JGT in water ambience have been examined in the laboratory by putting the JGT fabrics on static water for different periods (up to 150 days) and finally their loss in tensile strength have been measured.
Experiment on durability of treated JGT in Water Ambience
Durability of specially treated JGT in Water Ambience
0 20 40 60 80 100 120 140 1600
10
20
30
40
50
60
70
80
0 1.2 2.3 3 6.2 8.6 10.2 12.4
0
17.3
30 34.142.9
51.3 54.559.6
Untreated Treated
Days
% L
oss
in s
tren
gth
(War
p)
0 20 40 60 80 100 120 140 1600
10
20
30
40
50
60
70
80
0 1.6 2.6 3.4 5.612.4 14.4 17.8
0
14.5
26.331.8 34.7
49.2 53.157.2
Untreated Treated
Days
% L
oss
in s
tren
gth
(Wef
t)
Warp
Weft
Loss in Strength of Durable Woven Jute Geotextile under Water Ambience
Both untreated and treated JGTs were put in simulated experimental river bank conditions and finally % loss in tensile strength of both untreated (control) and specially treated JGT under combined soil and water ambience were measured up to 150 days.
Durability of Specially Treated woven JGT in Combined Water and Soil Ambience
Durability test of JGT in combined Soil-Water Ambience at IJIRA
Warp
Weft
Loss in Strength of Durable Woven Jute Geotextile under combined Soil-Water Ambience
0 20 40 60 80 100 120 140 1600
10
20
30
40
50
60
70
80
90
100
0 2 5.2 7.8 10.218.5 20.1 21.8
0
28.8
57.966.5
73.2
88.2 92.2 95.4
Untreated TreatedDays
% L
oss
in s
tren
gth
(War
p)
0 20 40 60 80 100 120 140 1600
10
20
30
40
50
60
70
80
90
100
0 2.4 3.2 512.4
20.8 22.4 23.6
0
24.834.8
50.5
64.772.8
78.689.4
Untreated TreatedDays
% L
oss
in s
tren
gth
(Wef
t)
(Microbial Count)(CFU/gm)
Soil Water
Bacteria 2.0x 107 2.7 x 102
Fungi 3.2 x104 Negligible
Microbial Analysis: As per Agar plate technique (AATCC 100, AATCC 30)
Microbial profile of soil & water used in durability test of treated JGT
Textural class of Soil used : Silt loam as tested by NBSS
Sample BOD5
(mg/L)COD
(mg/L)
Water 12 20
Water + untreated woven JGT 18 30
Water + specially treated woven JGT 16 26
Biological Oxygen Demand ( BOD) : IS 3025 (Part 44): 1993
Chemical Oxygen Demand ( COD) : IS 3025 (Part 58): 2006
Environmental Impact of durable woven Jute Geotextile
LIFE PREDICTION of specially treated woven Jute Geotextile (627 gsm ) had been carried out at IJIRA both under soil ambience and soil-water ambience and compared with untreated grey Jute Geotextile fabric. At different interval, loss in tensile strength was monitored and finally a statistical life prediction model as represented in has been suggested.
Life Prediction of Specially treated woven Jute Geotextile
Statistical Life Prediction of specially treated woven Jute Geotextile
Statistical Life Prediction of specially treated woven Jute Geotextile
Field Trial of Durable Woven JGT has been carried out
at the left bank of the river ( Bhagirathi, Shantipur, Nadia, West Bengal )
In association with:
1. National Jute Board (CFC-IJSG-21 Project)
2. Department of Irrigation and Water ways, Nadia Division Govt. of West Bengal
Bulk production of durable JGT Site of trial Performance Assessment of JGT
Field Trial on Specially Treated durable Woven Jute Geotextile
Identified chemical additives used to improve durability of woven JGT are aqueous based and readily available The effective add-on of the chemicals is low (0.5 %, w/w, approx.) and the weight gain of JGT fabric is negligibleThe loss of strength of the JGT fabric after treatment is within normal range (around 5%) Fabric characteristics of woven JGT are not affected much due to special treatmentSpecially treated woven JGT is rot-resistant & water repellentImproved functional properties is likely to increase the effectiveness of using such durable JGT in river bank protection
Contd…
Salient features of Durable Woven JGT
The treated JGT does not increase much the BOD and COD of water indicating no negative environmental impact Formulation developed for special treatment of JGT is user friendlyPredicted life of durable JGT is about two years in combined water-soil ambienceMay be considered as a cost effective alternative of copper and bitumen treatment in woven JGTFor large scale production of specially treated woven JGT, current cost of chemical is Rs. 12-14/- per sq.mt excluding its processing cost
Salient features of Durable Woven JGT
CONCLUSION
• Durable woven Jute Geotextile with improved anti-microbial and water repellent properties and useful life under combined soil-water ambience may be used for erosion control of river bank.
• Short and long term performance evaluation of durable woven JGT in erosion control of river bank are in progress.
ACKNOWLEDGEMENT
• National Jute Board, Ministry of Textiles, Govt. of India for
sponsoring the Project activity• CFC-IJSG-21 PROJECT for providing support in field
level performance evaluation of durable JGT in erosion control of river bank
Thank you