Sign In     |     Sign Up
Home / Articles / Application of jute fibres in foundation beds
Application of jute fibres in foundation beds
Textile Geo textiles

Application of jute fibres in foundation beds

Written by: Dr. Satyendra Mittal

Abstract


Jute is a coarse natural fibre. Two types of jute are commonly cultivated- corchorus capsularis (white jute) and corchorus olitorius (tossa jute). Only a small portion of the plant is utilized for extracting its fibre (approx 4-6%). An experimental investigation was taken up using this fiber in foundation beds. The tests in plane strain condition were performed on sand with randomly mixed jute fibers in different percentages of 0.125% to 1.0% by weight of dry sand with aspect ratios of 100 and 150. It has been observed that the jute fibres can be used for increase in bearing capacity of soil.


Physical and mechanical properties of jute fibres used in the study:


The jute fibres used in the study were torn pieces of jute bags and possesed following properties:


1) Weight (average)                - 800 gm/sqm

2) Thickness (average)           - 6 mm

3) Tensile strength (ultimate)  - 36 kN/m determined at a sample of 200mm X 100mm

4) Puncture strength              - 350 N/cm2

5) Density                             - 1.4 gm/cc


Experimental Work


For comparative evaluation of allowable bearing pressure of virgin sand and sand with randomly distributed jute fibers, the experimental work was conducted in laboratory and results were presented in the form of Load intensity v/s Settlement plot. The Experimental studies have been done for Plane strain tests conditions on soil with randomly mixed jute fibers. The tests were conducted with different percentage of jute fibers and at different aspect ratios.


Material Used For Experimental Work


Soil: The soil used in this study was locally available fine sand taken from locally available Solani River bed near Roorkee. The properties of soil were as below (Table 1). The soil classification was SM.


Table1: Properties of soil used in study:


Property

Value

Dry Density (kN/m3 )

16.7

Specific Gravity

2.61

Uniformity Coefficient, Cu

1.8

Max. void ratio (emax )

0.84

Min. void ratio (emin )

0.54

Liquid Limit (%)

Nil

Plastic Limit (%)

Nil


Jute: The jute as available locally was used for the study. The lengths of the jute fibres used for study were- 60mm (for aspect ratio =10) and 90mm (for. aspect ratio =15)


 

Test Procedure


All the tests were conducted in plane strain conditions. The test tank (Fig.1) was of dimension 800mmx75mmx350mm. Jute fibers were cut in 60mm and 90mm lengths corresponding to aspect ratios (A.R.s) 10 and 15 respectively to be randomly mixed with soil in various percentages as 0.125%, 0.25%, 0.50% 0.75% 1.0% by weight of soil. The mixed soil was placed in test tank at R.D. =30%. The Load was applied gradually through screw jack attached with Proving Ring of 5.0 kN capacity. The footing of size used in the tests was 75mmx75mm which was made of steel channel. The test was conducted like a normal plate load test till the failure occurred. The settlements were measured for each load applied on footing.




Fig. 1


Test Setup Used For Plane Strain Test Condition


Results and Discussions


Total 11 tests were conducted, 5 nos on each aspect ratio and one for unreinforced soil. The test results are reproduced in Table 2.


The results for these tests were plotted as Load Intensity v/s Settlement curve as shown in Figures 2 to 6. The Figures 7 and 8 show the results with increasing fibre contents for aspect ratios 10 and 15 respectively. The Fig. 9 shows the load intensity versus jute fibre content curve. It has been observed that bearing pressure increases with increase in jute fibres content (Fig. 9). Up to 0.5% jute fibres, there has not been significant improvement with bearing capacity with aspect ratio as 10, but for jute fibre more than 0.5%, the bearing capacity increases significantly for aspect ratio 15 than that for aspect ratio 10.


Table 2: Experimental Results


Types of soil

Allowable bearing pressure (kN/sqm.)

Virgin soil

104.50

Soil with Jute Fibers

A.R.=10

A.R.=15

Soil+0.125% jute fiber

135.00

142.00

Soil+0.25% jute fiber

190.00

196.00

Soil+0.50% jute fiber

242.00

248.89

Soil+0.75% jute fiber

371.00

444.44

Soil+1.00% jute fiber

533.33

640.00


This increase in bearing pressure is more at higher percentage of jute fibres. At aspect ratio 10, the bearing capacity is about five times and at aspect ratio 15, it is about six times that of virgin soil.


 

Load Intensity v/s Settlement Characteristics Curves:











 

Recommendations


Significant improvement in bearing capacity is observed when sand is reinforced with jute fiber. As the jute fiber has significant life (4 to 5 years after rot resistant treatment) and is available at practically no cost, the jute fiber reinforced sand bed can be a reliable foundation for rural housing on soft soils, foundation for temporary structure for the instrument storage, erection of heavy instrument at construction site, highway sub grade etc.


The aspect ratio (AR) as 15 causes more than 6 times increase in bearing capacity, hence can be adopted for sites with confidence. However, the AR as 10 also increases the bearing capacity by 5 times.


The jute fibres quantity by 0.5% of weight of dry soil may double the bearing capacity of virgin soil, hence may be adopted for sites.


The above findings are for the jute properties as mentioned in Table-1, which are the average properties of medium class jute. For higher class jute, the bearing capacity may still increase. However the laboratory model tests are recommended before suggesting its use.


Regulatory Issues & Suggestive Measures for Promotion of Jutes Use


It is evident from the above study that the jute can be used in foundation beds for improvement of bearing capacity of soils. Following are some points which if implemented, may promote not only production but also application of jute:


  • By starting degree or diploma courses on jute technology in various technical institutes.


  • By developing working models of jutes application in Civil engg. Projects


  • By arranging jute application demonstrations for media personalities and technocrats. Short films on jute applications be prepared and distributed. Electronic media be involved in popularizing jute use in engg sector


  • By arranging annual conferences on jute application


  • By instituting national awards on outstanding project with jutes use


  • By providing subsidy/ soft loans on the projects where jute is proposed to be used


  • By arranging hands on training to masons for jutes use in engg. Applications


  • By establishing jute helpline through internet


  • Patents be done for jute application technology, particularly for short term applications in ground improvement techniques


  • Research be done for longer life of jute when used with soil


  • Preparing a data base of successful projects and dissemination of that in technical institutes


  • Preparation of panel of consultants and making it available on line


  • Allocation of appreciable funds for Research & Development projects in research laboratories and technical institutions.


 

References


1)    Dey, B., Chand, P. and Singh, J. "Influence of Fibre on The Engineering Properties of soil", IGC-2003 'Geotechnical Engineering for Infrastructure Development' pp 394-399


2)    Gosavi Meenal, Patil, K.A., Mittal, Satyendra and Saran, S. "Improvement of Properties of Black Cotton Soil Subgrade through Natural Reinforcement", IGC-2003 'Geotechnical Engineering for Infrastructure Development' pp 379-383.


3)    Mehndiratta, H.C., Kumar, Praveen and Padma T., Natural Geotextiles in Highway Embankments-Indian Experience, Indian highways Journal, Vol. 33, No.12, pp 57-66, 2005.


4)    Rajagopal, K. and Ramakrishna, S. (1997) Degradation Behaviour of Jute Geotextiles within Clay Soils, Geosynthetic Asia97, 26-29 November, Bangalore, India, pp VI.33-VI.40.


5)    Ramakrishna, S. (1996) Investigation on Applications of Jute Reinforcement in Geotechnical Engineering, M.S. Thesis, Deptt. of Civil Engineering, IIT Madras, Chennai.


6)    Rao, G.V. and Balan, K. Reinforcing Sand with Jute Fibre, Geosynthetic Asia97, 26-29 November, Bangalore, India, pp VI.183-VI.190.


About the Author:


Dr. Satyendra Mittal is the Associate Professor in Civil Engineering Deptt. I.I.T. Roorkee, India


About the Article:


This article has been written in association with Mr. T. Sanyal who is a Consultant in JMDC, Kolkata, India and Ms. Rachna Vaish, who is associated with NIH, Roorkee.



To read more articles on Textile, Industry, Technical Textile, Dyes & Chemicals, Machinery, Fashion, Apparel, Technology, Retail, Leather, Footwear & Jewellery,  Software and General please visit http://articles.fibre2fashion.com


To promote your company, product and services via promotional article, follow this link: http://www.fibre2fashion.com/services/article-writing-service/content-promotion-services.asp


 

Leave your Comments

Follow us