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GLOBAL ACCEPTABILITY OF JUTE GEOTEXTILES-- ISSUES TO BE ADDRESSED & OVERALL STATUS OF CFC/IJSG/21 PROJECT . T SANYAL CHIEF CONSULTANT, NATIONAL JUTE BOARD, INDIA (PEA). INTRODUCTION.
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GLOBAL ACCEPTABILITY OF JUTE GEOTEXTILES-- ISSUES TO BE ADDRESSED & OVERALL STATUS OF CFC/IJSG/21 PROJECT T SANYAL CHIEF CONSULTANT, NATIONAL JUTE BOARD, INDIA (PEA)
INTRODUCTION • The on-going international project on Jute Geotextiles (CFC/IJSG/21) has before it a number of goals that are required to be achieved for successful completion of the project. • The first goal is to substantiate efficacy of Jute Geotextiles (JGT) in three specified applications viz rural road construction, riverbank erosion control & hill slope stabilization. • The next in priority is to identify the potentially important JGT for the said applications which implies the specifications of JGT have to be optimized for the specified end-uses • Thirdly, an acceptable methodology of design for JGT will have to be evolved • And most importantly standardization of application & products have to be secured at national & international levels.
INTRODUCTION contd • And all these tasks are to be completed within the approved project tenure • Admittedly there has been delay in start of field trials (16 in India & 10 in B’desh), for reasons beyond the control of PEA & CIs. As a result, time overrun in execution with corresponding delay in monitoring could not be avoided • The period of monitoring at disposal would thus be inadequate for collection of at least 6 sets of field performance data for each trial site, justifying extension of the project by at least 1 ½ years . • Given the time-constraint, all FAs associated with the project need to hasten their activities and address the critical issues .
Proving efficacy of JGT • There are three stages involved #1—compilation of field and lab data of JGT applications previously done in the three specified sectors and their analysis #2—collection & collation of data from the field trials under the project along with concurrent lab. scale studies #3—ensuring authenticity of test results (reliability of instruments and operation) #4—comparartive analysis of all data and drawing inference
Identifying the appropriate JGT • Steps are #1—deciding the basic parameters of design such as tensile strength , porometry of the fabric separately for the three specified applications #2—optimizing JGT specifications for each application without compromising the technical requirements with an eye to ease of manufacture and economy #3—testing manufacture-worthiness of the designed fabric
Design methodology • This is the critical part of the project in view of unique features of jute & JGT. • In developed countries attempt has been made to finalize application-specific design methodologies on the basis of rigorous empirical exercises in field and laboratory • In case of JGT no such coordinated and systematic empirical exercises have been taken up. We have to depend on the basic theoretical concepts followed in case of man-made GT refined on the basis of available results and experience. • PEA has drafted design methodologies for each of the three applications that require critical review for global acceptibility
Standardization • Standardization process will start after efficacy of JGT in all the three applications is substantiated • Standardization in India & B’desh should precede global accreditation process • Based on nearly 150 field applications in India with JGT, BI Standards for all the three applications have been published. B’desh should initiate actions in this respect if appropriate • These standards may require revision after conclusive findings are available on completion of field trials and simulation studies taken up in both the countries
FIELD TRIALS & TESTS The issues regarding field trials & tests are – • Completion of monitoring within a reasonable time involvingcollection of at least 6 sets of field data for each site, their analysis by the respective countries & drawing of inferences which need be shared & consented by the two countries for arriving at a uniform set of recommendations. • The quality & specs of JGT used and materials utilized in trials and also workmanship are also to be considered. • Reliability of tests is also a critical factor needing accreditation of the test labs. In India NABL accreditation of the test lab at DJFT, CU (erstwhile IJT) is in the final stages. In B’desh similar such steps should be taken in hand.
FABRIC ENGINEERING • The primary aim of the project is to reduce the number of JGT types now in use and to identify only potentially important types suitable for application in low volume road and erosion control (in riverbank & hill slope) • Rationalization and optimization of the fabric design parameters • Economizing cost of JGT without compromising the design parameters is also a concurrent objective. • With these objectives 2 types of woven JGT –one for low volume road constn & the other for riverbank erosion control –and 3 types of open weave JGT have been designed by IJIRA validated by tests conducted by DJFT, Calcutta University • The types are 724 gsm for road, 627 gsm for river bank & 500, 600 & 700 gsm for hill slope
FABRIC ENGINEERING contd • The two types of newly designed woven JGT have been applied in field trials in India & B’deshand also in the prototype study on the test track constructed by the PEA at Kolkata and in the simulation study by NSRI, UK • 3 types of O W JGT designed for hill slope protection is under trial at the CSWCRTI farm in Ooty, India. If possible, attempt will be made to select 2 types out of 3 based on the findings of field trial and prototype study. • NSRI, UK is also conducting simulation study on slope independently. BUET has also conducted simulation studies in slope. • The next step will be to analyze the field & lab findings to arrive at a rational conclusion about final selection of the end-use specific type (s) of OW JGT and woven JGT for the three specific areas.
APPLICATION-SPECIFIC DESIGN METHODOLOGY • This is a challenging task for two reasons- --no such design method exists for JGT considering its unique features and bio-degradability factor of jute --design methods for man-made GT are based on empirical relations varying from country to country • Based on previous and current experience PEA has developed provisional design methodologies with JGT for rural road strengthening, riverbank erosion control & hill slope stabilization considering the parameters standardized in India. This requires endorsement by the two Standardization Committees • PEA will fine-tune the design methodologies based on further inputs of NSRI, BUET & CSWCRTI.
STANDARDIZATION COMMITTEES IN INDIA & B’DESH • In view of the above, contribution of the two Standardization Committees assumes great importance. While collection of field data & collation of findings will be the tasks principally of BUET in B’desh & BESUS in India, two SCs will need to examine the inferences carefully and endorse them • This is a collective responsibility of the SCs. The members of the two committees will exchange their views for modification & refinement of the conclusions • Both India & B’deshthereafter will approach the Standard-making bodies of the two countries for publishing Standards. The next step would be to approach ISO/CEN-TC 189 to secure global accreditation of the products with related specific applications
MARKETABILITY OF JGT • Marketability of JGT for the three specific applications will get a boost once the Standards at the national level are published based on the findings of the project. There will be strong ground to apply for global accreditation after that • Marketability of JGT in general depends on the positive intentions & proactive action of the manufacturers who need to realize that JGT can open up a life line for jute industry considering its possibility of large scale usage in domestic as well as in the international market due to global concerns about environment
Latest Status of the Project (up to PY 4) Component I • PwC, the entrusted agency for both the countries, is continuing with data compilation on end-use requirements with concurrent focus on European countries. • Theagencyhas submitted an interim analysis of supply & value chain. The activity is continuing with focus on primary research
Latest Status of the Project (up to PY 4) COMPONENT II • 2 types of woven (20 kN/m-627 gsm & 25 kN/m -724 gsm), 3 types of open weave JGT (500, 600 & 700 gsm) & 1 type of non-woven (500 gsm) JGT have finally identified as potentially important considering functional requirements, ease of manufacture and economy.
COMPONENT II (contd) • Field Trials • The project envisages 26 field trials (16 in India and 10 in Bangladesh). • 16 field trials in India comprise 7 + 1 addl sites for rural roads, 6 for riverbank erosion control & 3 +5 addl sites for hill slope. 10 field trials in B’deshcomprise 5 + 1 addlsites for rural roads, 3 +2 addl sites for river bank erosion control& 2 +1 addl sites for hill slope. • Additional field trials have been taken up to lend variety for comprehensive assessment of performance • Field trials in India have been completed while two field trials in B’desh are expected to be completed within a month
Interim Findings for Rural Roads • Soil consolidation being a protracted process, more time is needed for conclusive results on sub-grade bearing capacity to show up. • In the roads which have been completed a year or so back, CBR% has increased by more than 1.5 times in India. The initial CBR was of the order of 2.2% to 2.8% • In B’desh the increment of CBR% is more than 3 times in about 18 months as reported by BUET. (BUET will present details) • The rate of soil consolidation depends on the soil type and ground conditions and influences rate of improvement of sub-grade CBR%.
Interim Findings for R/bank Erosion Control • There has been no report about bank-distresses so far. We have tested bank soil before the monsoon & shall repeat it in subsequent months for comparison. • Hydraulic data of 3 rivers in India (rivers Fulahar, Kaljani & Jagaddal)have been collected by using ADCP, a state-of-the-art sensor -based instrument through KoPTalong with satellite imageries to have an idea of the probable change in river behavior • In B’desh such observations could not be done for non-availability of ADCP facility.
Interim Findings for Hill Slope • All the hill slopes treated with open weave JGT are in good shape even after unusual rains in the northern part of India last year. • CSWCRTI has submitted interim reports with some inconsistency in results. It is felt that observation stretching for at least 3 years will be needed to reach a final conclusion on comparative efficacy of the three types of OW JGT used under diff parameters • Regarding the hill slope on NH 55 in West Bengal (additional site), a paper on the outcome has been published documenting the pre-work & post-work situation and performance
SIMULATION STUDIES Status in India • As physical simulation for river-related works is not feasible considering the extent and variability of the influencing parameters, a design methodology based on field trial performance in river bank protection has been drafted by PEA. • Design methodologies for rural roads and hill slope stabilization have also been drafted by PEA separately based on the available results of simulation & prototype studies/field trials with JGT & man-made GT. • The documents await endorsement by the Standardization Committees
Prototype Studies on JGT • A Test Track for prototype study along with comparative evaluation of different types of JGT & SGT on rural roads has been constructed on NJB land at New Town, Kolkata. • Design load application (80,000 ESAL), rut depth measurement and BBD test on sections with bituminous overlay also have also been done. • CSWCRTI has undertaken separately a prototype study on hill slope at Ooty, Nilgiri Hills.
Interim assessment of performance of the test track at Kolkata • Traffic Benefit Ratio (TBR)—a safety factor indicated by comparative load carrying capacity of a pavement with & without reinforcement is assessed by the following relation-- No of passes to reach a given rut depth with reinf (JGT) No of passes to reach the same rut depth without reinf • TBR of the test track works out to2.3to reach a rut depth of 12.5 mm with JGT (4000 passes) vis-à-vis 1750 passes without any reinforcement (conventional design) to reach the same rut depth. • Rut depth is within 17.50 mm after two observations—within prescribed permissible limits for low volume roads • Inference –Performance OK
Interim assessment of performance of the test track at Kolkata contd Analysis of other results • CBR of sub-grade increased most for the section with 25 kN/m JGT in the sub-grade on imposition of design load (80,000 ESAL i.e. 4000 passes) after 15 months (the section is without PMC) • Rutting was the lowest in the section treated with 20 kN/m JGT. (the section has PMC on top) • Base Course Reduction (BCR) is calculated to be 15.4% as a result of application of JGT as per Guidelines of IRC:SP:72:2008
Simulation Studies by NSRI, Cranfield University, U.K. • A simulated rural road has been installed in experimental facility of NSRI, Cranfield University, UK incorporating 5 treatments, (1) control (no geotextile), (2) 20kN jute woven, (3) 25kN jute woven, (4) geosynthetic and (5) control (no geotextile; deeper subgrade) as has been done in Test Track at Kolkata. Specification of the road construction conforms to IRC:SP:72:2007. Loaded wheel testing rig has been set up for trial. • Simulated slope with rain-fall simulation arrangement have also been installed for corroboration of the results of field trials for slope erosion control.
Interim Status of NSRI Study Reg. Surficial soil erosion control, NSRI is working on collection & collation of data on • Slope hydrology (run-off & infiltration) and erosion rate with different JGT types under varying soil conditions. The data relate to -total run-off volume -time taken for run-off generation & run-off velocity -maxm run-off velocity a JGT type can sustain in -total sediment yield (erosion) & its concentration -vegetation establishment & growth (bio-mass) • The data will be exchanged with CSWCRTI for conclusive findings
Interim Status of NSRI Study Reg. rural road construction, NSRI is following the identical design with 5 different types of JGT & GT treatment (advised by BESUS) as has been done in the Prototype Study at Kolkata and collecting data • The purpose is to evaluate performance of each pavement with specified JGT & GT as measured by CBR of the sub-grade & surface characteristics. • Additionally laser-scanning was done on the simulated pavement to determine surface characteristics • The interim findings are inconclusive. NSRI has been requested to review
Prototype Study on Slope Erosion Control with OW JGT at Ooty • CSWCRTI is carrying out two prototype studies at Ooty in India. • The first study is on a fixed slope with tea saplings as vegetation • The second study is on two different slopes with a species of grass as vegetation • Interim observations point out to variability of results on a time scale. At least three years of observation would be necessary for drawing inferences.
SIMULATION STUDIES IN B’DESH • Status • BUET has undertaken a model study to conduct laboratory simulation for re-verification of the performance of the preliminarily identified potential JGT for hill slope protection under varying ground and environment conditions. • BUET will present the interim findings
Economical Advantages of using JGT • PEA has assessed direct economical advantages of using JGT. • The cost advantage could be of the order of 10% in case of low volume road application & of the order of 20% in case of riverbank protection based on West Bengal SoR. • For surface soil erosion control applications as in hill slope, open weave JGT is more competitively priced than coir geotextiles and synthetic geotextiles of similar type based on prevalent rates in India. Moreover overland storage and reduction of run-off velocity is the highest in case of OW JGT. • The related paper is included in the publication of NJB (PEA) on the proceedings of the National Seminar organized in India in September 2013 for the project
Component III • In India 26 samples of woven JGT of 5 different constructions for rural road / river bank protection and 12 samples of open weave JGT of 4 different constructions for hill slope protection were designed & developed by PEA / IJIRA / IJT (now DJFT, CU), manufactured by 7 & 4 jute mills respectively & tested in the laboratory of IJT (now DJFT, Calcutta University) to determine functional suitability.
COMPONENT III contd Standardization Status • 3 BI Standards on guidelines for use of JGT in slope, rural road construction & river bank erosion control have been published • In addition a revised draft replacing the existing BI Standard on woven JGT is under preparation with the help of IJIRA • The Indian Roads Congress has published a state-of-the-art document on JGT application in low volume road, slope & landslide authored jointly by CRRI & NJB • Indian Railways (RD&SO) has also published ‘Guidelines on JGT for application in rly embankment & hill slope’
Component III contd • IIT , Kharagpur has developed an eco-friendly durable & water-repellent additivefor river-related applications with funding from NJB under Jute Technology Mission.This is reportedly a better and cheaper substitute of the conventional bituminized JGT so far in use. • IJIRA has also developed a water-repellent additive to enhance durability of JGT in water-affected applications. • JGT with both the treatments has been used on the left bank of the river Bhagirathi at Santipur, Dt Nadia. Performance of the treatments is being monitored.
COMPONENT IV • The process of dissemination of the findings and exchange of knowledge / information developed in the project is continuing through publications (e.g.manual, evaluation of performance), Awareness Workshops in India / Bangladesh and abroad. • A national seminar focusing achievements under the project in India was held on 19th Sept 2013 at Kolkata. The current seminar at Dhaka is a reciprocal program highlighting achievements under the project in B’desh • NJB has published an anthology of authentic papers on JGT and has documented the papers presented in the National Seminar in a printed volume at Kolkata. PEA is keeping track of the papers published in journals and intends to publish another such volume containing salient findings under the project. The manual is also under revision by PEA
COMPONENT V MID-TERM APPRAISAL OF THE PROJECT • The project is managed by the CIs of the two countries with overall superintendence of the PEA (NJB). IJSG is the Supervisory Body • CFC engaged Wazir Advisors P Ltd, a consultancy outfit based in India, for undertaking a mid-term appraisal of the project. • The purpose was to ascertain as to whether the project has been proceeding in the desired direction. • Final report of WAPL has been accepted by CFC.
CLOSURE • As usage of JGT is confined to sectors controlled by the Govt in both the countries patronage of the govts at the initial stages is a necessity • Jute being essentially a labour-oriented industry on which millions depend in both the countries for survival, such patronage for JGT is not an out-of-the bill proposition. Poverty alleviation being one of the major aims of the project there is need to ensure large and consistent uptake of jute for making of JGT. • It is pertinent to point out that monopoly of jute in sack-making being on wane JGT can stand jute industry in good stead due to its bulk consumption