Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-2, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
Experimental Studies on Strength Characteristics of Expansive Soil Treated With Zycobond P. Rajendra Kumarr1 & P. Archana2 1
Associate Professor, Department of Civil Engineering, KSRM College of Engineering (Autonomous), Kadapa, A.P., India. 2 M.Tech Scholar, Department of Civil Engineering, KSRM College of Engineering (Autonomous), Kadapa, A.P., India.
Abstract: Geotechnical engineering face various problems while designing the foundations on highly compressible clayey soil due to poor bearing capacity and excessive settlement. Most of the soil available are such that they have good compressive strength adequate shear strength but weak in tension/ poor tensile strength. To overcome the same many researchers have concentrated their studies on soil improvement techniques by developing new such materials, through the elaboration of composites. The main objective of this study is to investigate the effect of fibers in geotechnical applications and to evaluate the
strength of unsaturated soil by carrying out compaction test and CBR tests on soil sample. The fibers are cut in length of 6mm and 12 mm and mix randomly in varying percentages (0.50%, 1.0%, 2.0%, 4.0%) by dry weight of soil and compacted to maximum dry density at optimum moisture content. The test results indicate a reduction in the maximum dry density and optimum moisture content of soil due to the addition of Recorn fiber. It also indicates an improvement in the CBR value. Keywords: Expansive soil, Recron Fiber, CBR.
INTRODUCTION For any land-based structure, the foundation is very important and has to be strong to support the entire structure. In order for the foundation to be strong, the soil around it plays a very critical role. So, to work with soils, we need to have proper knowledge about their properties and factors which affect their behavior. The process of soil stabilization helps to achieve the required properties in a soil needed for the construction work. From the beginning of construction work, the necessity of enhancing soil properties has come to the light. Ancient civilizations of the Chinese, Romans and Incas utilized various methods to improve soil strength etc., some of these methods were so effective that their buildings and roads still exist. In India, the modern early of soil stabilization began in early 1970’s, with a general shortage of petroleum and aggregates, it became necessary for the engineers to look at means to improve soil other than replacing the poor soil at the building site. Soil stabilization was used but due to the use of obsolete methods and also due to the absence of proper technique, soil stabilization lost favor. In recent times, with the increase in the demand for infrastructure, raw materials and fuel, soil stabilization has started to take a new shape. With the availability of better research, materials and equipment, it is emerging as a popular and cost-effective method for soil improvement.
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Here, in this project, soil stabilization has been done with the help of randomly distributed polyester (Recron) fibers obtained from waste materials. The improvement in the shear strength parameters has been stressed upon and comparative studies have been carried out using different methods of shear resistance measurement.
OBJECTIVE The main objective of the present work is to study the physical and geotechnical properties of Expansive soils available at KSRM college of engineering, Kadapa to study the strength properties of soil by addition Recron Fiber and at different percentages i.e., 0.5%, 1%, 2%, 4% and to study the usage of Recron fiber for finding the geotechnical properties of soil.
MATERIALS Following are the materials which are used in the present study: Expansive Soil: In this study, the investigation is carried out on soil samples which are collected at Tadigottla village near KSRM college of engineering which in black in colour with high moistures content. The following table shows the various soil properties obtained:
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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-2, 2017 ISSN: 2454-1362, http://www.onlinejournal.in Table 1: Test results of Soil properties S.NO.
EXPERIMENT
RESULT
PERMISSIBLE LIMITS
IS CODE
1
Specific Gravity
2.48
2.6 to 2.7
IS-2720 Part-3, section 11980
2
Free Swell Index
75%
>50%
IS-2720, Part-40, 1977
3
Liquid limit
88%
40% to 100%
4
Plastic limit
48.4%
20% to 65%
5
Plasticity index
57.6%
20% to 60%
Standard Proctor Compaction
OMC-22.3%
6
20 to 30%
MDD- 1.52g/cc
1.2 to 1.8
Unsoaked-27.06
--
Soaked-1.46
--
7
California Bearing Ratio
IS-2720, Part-5,1985
IS-2720, Part-7, 1980/1987
IS-2720, Part-16,1979
RECRON FIBER: Recron 3S is modified polyester. It is generally used as reinforcing material in concrete and soil to increase their performance. Polyster (Recron) fibre used for the test having different sizes 6mm and 12mm. These fibers were made from polymerization of pure teraphthalic acid and Mono Ethylene Glycol using a catalyst. These fibers were found to be widely used in concrete technology which has a special triangular cross-section and equivalent diameter of fiber was about 32 μm– 55 μm.
Analysis of Results 1.
2.
3.
4.
METHODOLOGY In this work, different engineering and index properties of the soil were studied and then the synthetic fiber is contributed in the soil as per the aspect ratio 6mm, 12mm from 0.5% to 4% by doubling the initial percentage of aspect ratio of fiber to the soil.
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5.
From the series of standard proctor tests conducted, we found that the OMC of the reinforce soil increases with the gain of the fiber content. MDD of the reinforced soil decreases as compared to OMC with the fiber content increase. OMC of the reinforced soil increments with the rise of length of the fiber and MDD decrease. Unsoaked CBR of the reinforced soil is higher as compared to the soaked CBR of the reinforced soil. The increase in the CBR value is due to the reason that the inclusion of randomly distributed fiber into the soil improves its load and deformation behaviour.
The following are the graphs obtained at different percentage of Zycobond
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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-2, 2017 ISSN: 2454-1362, http://www.onlinejournal.in 1.
Graphs for OMC & MDD:
optimum moisture comtent (OMC)
% of fiber Vs OMC 30 25 20 15
6 mm length
10
12 mm length
5 0 0.5
1
2
4
% of fiber Fig.No.1: Comprassion of fiber with OMC
maximum dry density (MDD)
% of fiber Vs MDD 5 4 3 2
6 mm length
1
12 mm length
0 0.5
1
2
4
% of fiber Figure:1 Comprassion of fiber with MDD
2.Graphs for CBR:
Variation of Unsoaked & Soaked CBR of soil with 6 mm length of fiber CBR Values
5 4 3 2
Unsoaked CBR
1
Soaked CBR
0 0
0.5
1
2
4
% of fiber
Figure No:2 Variation of Unsoaked & Soaked CBR of soil with 6 mm length of Recron fiber
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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-2, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
CBR Values
Variation of Unsoaked & Soaked CBR of soil with 12 mm Recron fiber 6 5 4 3 2 1 0
Unsoaked CBR Soaked CBR 0
0.5
1
2
4
% of fiber Figure No:3 Variation of Unsoaked & Soaked CBR of soil with 12 mm length of Recron fiber
CONCLUSION
From the series of standard proctor tests conducted, we found that the OMC of the reinforce soil increases with the gain of the fiber content. MDD of the reinforced soil decreases as compared to OMC with the fiber content increase. OMC of the reinforced soil increments with the rise of length of the fiber and MDD decrease. Unsoaked CBR of the unreinforced soil is low and it provides an opportunity to be improved for the further purposes. CBR of the reinforced soil for the aspect ratio 6 mm and 12 mm increases to 76.37%,106.30% as compared to the unreinforced soil. The percentage of unsoaked CBR value increases with the increase in the fiber content and also with increase of length of the fiber. Soaked CBR of the reinforced soil for the aspect ratios 6 mm and 12 mm increase to 58.47% and 98.30% as compared to the unreinforced soil. Unsoaked CBR of the reinforced soil is higher as compared to the soaked CBR of the reinforced soil. The increase in the CBR value is due to the reason that the inclusion of randomly distributed fiber into the soil improves its load and deformation behaviour. CBR value of the reinforced soil was observed to be greater than that of the unreinforced soil by the increase in the fiber content.
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REFERENCES Cai, Y., Shi, B., Charles, W.W. Ng. & Tang, C. (2006) “Effect of polypropylene fiber and lime admixture on engineering properties of clayey soil”, Engineering Geology 87, 230– 240. Chandra S., Viladkar, M.N. and Nagrrale P.P. (2008),”Mechanistic Approach for fibre reinforced flexible pavements” Journals of Transportation Engineering ,Vol. 134,15-23. Consoli, N.C., Montardo, J.P., Prietto, P.D.M., and Pasa, G.S. (2002). "Engineering behaviour of sand reinforced with plastic waste." Geotechnical and Geological Engineering, ASCE, 128(6), 462-472. Freitag, D.R. 1986 “Soil randomly reinforced with fibers”, Journal of Geotechnical Engineering ASCE 112 (8), pp. 823–826 Gosavi, M., Patil, K.A, Mittal, S. and Saran, S (2004). “Improvements of properties of black cotton soil sub grade through synthetic reinforcement”, Journal of Institution of Engineers (India), 84,257262. H. Jiang, Y. Cai and J. Liu (2010), “Engineering properties of soils reinforced by short discrete polypropylene fiber”, Journal of Materials In Civil Engineering, 22, pp. 1315-1322. Hoover, J.M., Moeller, D.T., Pitt, J.M., Smith, S.G., Wainaina, N.W. (1982) “Performance of randomly oriented fiber reinforced roadway soils”. Iowa DOT Project-HR-211. Department of Transportation
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IS: 2720, Part VII, 1965, Determination of Moisture content –Dry density Relation using Light Compaction, Bureau of Indian Standards; New Delhi IS: 2720, Part XVI, 1965, Laboratory determination of CBR, Bureau of Indian Standards; New Delhi. Mali.S and Baleshwar Singh, (2014). “Strength Behaviour of Cohesive Soils Reinforced with Fibers” International Journal of Civil Engineering Research, 5 (4), pp. 353-360 Maliakal, T and Thiyyakkandi, S., (2013). “Influence of randomly distributed coir fibers on shear strength of clay”, Geotechnical and Geological Engineering, 31(2), pp. 425–433. Manjesh, L., Ramesh, N.H. Kumar Mohan, Siva pullaiah, V.P., 2003. “CBR values of soil-fly ash mixture for road construction”. Proceedings of Indian Geotechnical Conference, Roorkee, pp. 451–454. P. Pradhan, R. Karand and A.Naik (2012), “Effect of random inclusion of polypropylene fibers on strength characteristics of cohesive soil”, Geotechnical and Geological Engineering, 30(1), pp. 15-25 Prabhakar, J., Sridhar, R.S. (2002)” Effect of random inclusion of sisal fibre on strength behaviour of soil”. Construction and Building Materials 16, 123–131. Puppala, A.J., and Musenda, C., (2002). “Effect of fibre reinforcement on strength and volume change in expansive soils”, Transportation Research Record, No:000716, pp. 134-140. S. Akbulut, S. Arasan and E. Kalkan (2007),” Modification of clayey soils using scrap tire rubber and synthetic fibers”, Applied Clay Science, 38, pp. 2332. Saran, S. (2010). “Reinforced soil and its engineering applications”, I.K. International Publishing House Pvt. Ltd., New Delhi. Satyanarayana Reddy, C.N.V., Rama Moorthy, N.V., 2004.“Geotechnical investigations into flexible pavement design over a clay sub grade”. Indian Geotechnical Conference, Warangal, pp. 514–517. [ Singh, H.P., and Bagra, M. (2013), “Improvement in CBR value of soil reinforced with Jute Fiber”, International Journal of Innovative Research in Science,
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Engineering and Technology, 2 (8), 34473452
ACKNOWLEDGEMENT We Sincerely thankful to management, Director, Principal of KSRM College of Engineering (Autonomous) and we sincere gratitude to HOD of Civil Engineering Prof. A.Mohan for providing sufficient environment and lab equipments.
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