Green Stabilization of Coimbatore Clay Abstract - Soil stabilization is the process of improving the engineering properties of weak soil and thus making it more stable. Quarry dust (QD), Fly ash (FA) was added to Clay in varying proportions of 10%, 20%, 30%, 40%, 50% and 60%. Similarly Waste Paper Sludge Ash (WPSA) was added to Clay in varying proportions of 2%, 4%, 6%, 8%, 10% and 12% and the geotechnical properties are studied. With the optimum proportion obtained on treating Soil with QD, FA and WPSA, Polypropylene Fibre (PF) is added to it in varying contents of 0.5%, 1.0%, 1.5% and 2.0%. The conclusion drawn from this investigation is that Clay stabilized with QD and PF showed optimum performance in dosage of 30% and 1.0% respectively by weight of Soil. Clay stabilized with FA and PF showed optimum performance in dosage of 40% and 1.0% respectively by weight of Soil. Clay stabilized with WPSA and PF showed optimum performance in dosage of 8% and 0.5% respectively by weight of Soil. Thus inclusion of PF enhances the performance of Clay - Quarry dust, Clay - Fly ash, Clay - Waste Paper Sludge Ash. Index terms: Quarry dust, Fly ash, Waste Paper Sludge Ash, DFS, Plasticity characteristics, OMC, MDD, UCS. I. INTRODUCTION Clay possesses great threat for the construction of buildings due to its less characteristic shear strength and high swelling characteristics. In order to control this behavior, the cohesive soils have to be suitably treated with chemicals or any other available materials which can alter its engineering behavior. The Clay used in the study is collected in Coimbatore which having latitude 11 01ʹ22.063ʺ N and longitude 76 56ʹ37.624ʺ E. Based on the test results, the clay is classified as Clay of high compressibility (CH) as per ( BIS 1498 1970 ). Aggregate crusher units produce enormous quantities of quarry dust, a byproduct obtained during crushing of rubble. Stacking or disposal of such large quantities of this waste leads to serious environmental problems and health hazards. The QD used in the study is collected near Chettipalayam in Perur at Coimbatore. FA is a waste product produced mostly from the burning of coal in thermal power stations, which contributes to environmental pollution. The Fly ash (class F) used in the study is collected from METTUR Thermal power Plant, Tamilnadu, India. Waste Paper Sludge Ash (WPSA) is considered as finely waste product resulting from the combustion of waste paper sludge in paper recycling factories. Waste paper Sludge Ash used in the study is collected from Amman Paper mill near Madathukulam in Vayalur at Palani. Polypropylene also known as Polypropene is a thermoplastic polymer used in a wide variety of applications (Cera- chem Fibre mix). These fibers are differentiated based on their length. Aspect ratio of fibre used is 150. The Polypropylene fibre used in the study is R.Vinothkumar, Dr.P.D.Arumairaj 234 collected from the Cera-Chem Private Ltd, near Kilpauk Garden Colony, Chennai. QD was added to clay in varying proportions of 10%, 20%, 30%, 40% and 50%. FA was added to clay in varying proportions of 10%, 20%, 30%, 40%, 50% and 60%. WPSA was added to clay in varying proportions of 2%, 4%, 6%, 8%, 10% and 12% and its effect on the geotechnical properties are studied. II. OBJECTIVE OF STUDY 1) The main objective of the project is to study the effect of replacement of part of clay with quarry dust, fly ash, waste paper sludge ash and polypropylene fibre as stabilizing agents in varying proportions and to determine an optimum dose of the stabilizing agents. 2) The effect of plasticity characteristics, compaction characteristics and shear strength properties of soil are discussed based on the results obtained. III. LITERATURE REVIEW M.N.Fatani, G.H.Bauer and N. Al-Joulani (1991) [3] studied the effect of both aligned and randomly oriented metallic fibres on silty sand. It was found that mixing fibres with silty sand soil will increase the peak strength and residual strength 100% and 300% respectively over the untreated soil. S.Ziegler, D.Leshchinsky, H.I. Ling (1998) [4] studied the effect of short polymeric fibres on crack behaviour of clay subjected to drying and wetting conditions. He concluded that the addition of fibres to the clay soil is very effective in reducing the amount of desiccation cracking and increasing the tensile strength. D.R.Freitag (1986) [9] mixed the fibre with clayey soil and showed that addition of fibre will increase the strength and ductility than plain clayey soil. [16] Quadri Syed Ghausuddin (2011) conducted studies on evaluation of Soil-Quarry Dust Mixtures Reinforced with Polypropylene Fibres. The objective of this paper is to analyze the replacement of weak earth material with quarry dust using polypropylene fibres as reinforcements and to investigate the influence of selected fibre parameters like fibre content and fibre length on the strength and ductility behavior of soilquarry dust mixtures. A series of tests like Compaction test &California bearing ratio tests were carried out. Polypropylene fibres with different fibre length (12mm, 24mm and 40mm) were used as reinforcement. The conclusion drawn from this investigation is that polypropylene fibres of 24mm length showed optimum performance in dosage of 1.00% by weight of soil quarry dust mixtures. Thus inclusion of randomly oriented fibres greatly influences the performance of soil quarry dust mix.
Kaniraj and Gayatri (2003) [ 14 ] indicated that 1% polyester fibers (6 mm length) increased strength of raw fly ash and change their brittle failure into ductile one. P.B.Nagarnaik and Pradip D. Jadhao ( 2008) [ 12 ] conducted studies on the Performance Evaluation of Fibre Reinforced Soil- Fly Ash Mixtures. Fly ash is a waste produced from thermal power stations, which contributes to environmental pollution. Proper and effective disposal of fly ash is a big task and efforts are underway to improve the use of fly ash in several ways. A number of studies have been conducted to investigate the influence of randomly oriented fibres on the strength behavior of coarse grained and fine grained soils. However, the influence of selected fibre parameters i.e., content and length on the strength and ductility behavior of soil fly ash mixtures has not been reported so as much detail as in the case of the soils. specimens of soil fly ash mixtures were tested with 0, 0.5, 1.0,1.5 and 2.0 per cent polypropylene fibres with various lengths of fibres. The results showed that the inclusion of randomly distributed fibres significantly increased UCS, residual strength and absorbed energy of soil fly ash mixtures. The increase in UCS, residual strength and absorbed energy was function of fibre content and length. UCS, residual strength and absorbed energy increased with increasing fibre content. P.Segui, J.E. Aubert, B.Husson, M.Measson (2012) [ 7 ] presented paper on Valorization of Wastepaper Sludge Ash as Main Component of Hydraulic Road Binder. This paper deals with the valorization of wastepaper sludge ash (WPSA) as the main component of Hydraulic Road Binder (HRB). The physical, chemical and mineralogical characteristics of this WPSA were studied and this characterization was completed by a study of the reactivity of WPSA in presence of lime and gypsum. This study led to the optimization of HRB rich in WSA whose characteristics were tested on mortars and on samples of treated soil. The characterization of WPSA and the study of its reactivity showed that WPSA had hydraulic properties because of the presence of hydraulic minerals: lime (CaO), mayenite (Ca 12 Al 14 O 33 ) and α - Ca 2 SiO 4. The compressive strength of WPSA containing mortars was strongly penalized by the high water demand of the ash but this was not the case for the samples of treated soils.all the results obtained in this study permit us to conclude that WSA is suitable for use as the main component of HRB. This study is a good example of waste valorization: firstly, the calorific value of sludge produced by the paper recycling industry is recovered at the industrial plant and, secondly, the ash formed during this incineration process is reused as the main component of HRB with interesting added value. M.C.Monte E.Fuente, A.Blanco, C.Negro (2009) [ 5 ] presented paper on Waste management from pulp and paper production. The production of pulp and paper from virgin pulp generates less waste but the waste has similar 235 properties to waste from the production of deinked pulp, although with less inorganic. Due to the large volumes of waste generated, the high moisture content of the waste and the changing waste composition as a result of process conditions, recovery methods are usually expensive and their environmental impact is still uncertain. For this reason, it is necessary to continue research on different applications of wastes, while taking into account the environmental and economic factors of these waste treatments. IV. EXPERIMENTAL STUDY The experimental study involves particle size distribution, Atterberg s limits test, standard Proctor s compaction tests, differential free swell index test and unconfined compressive test on virgin soil and soil treated with QD, FA and WPSA in varying proportions. With the Optimum proportion obtained on treating Soil with QD, FA, and WPSA Polypropylene fibre is added to it in varying contents of 0.5%, 1.0%, 1.5% and 2.0% respectively. The results obtained are discussed below. The Schematic diagram represents the collection of Samples shown in Fig 1,2,3,4,5 and6. Fig 1. Quarry Dust Fig 2. Fly ash
Fig 3. Waste Paper Sludge (WPS) during Wet condition Fig 4. Burning of WPS Fig 5. Waste Paper Sludge Ash Fig 6. Polypropylene Fibre V. RESULTS AND DISCUSSION Table 1. The properties of Coimbatore clay S.NO PROPERTY Value REMARKS 1 Natural moisture content 12.695% - 2 Specific - 2.78 Gravity 3 % of Gravel 0% - 4 % of Sand 29.15% - 5 % of Silt 14.17% - 6 % of Clay 56.68% - 7 DFS 70% Since DFS >50% Degree of Expansion is Very High. Since (W L ) > 8 50% Liquid limit (W L ) 58% Compressibility is High 9 Plastic limit (W P ) 25% 10 Plasticity index Since ( I 33% P ) > 17 ( I P ) High Plasticity 11 Since (W Shrinkage limit S ) lies 8.38% ( 7-12 )% Swell (W S ) potential is High 12 Flow Index ( I f ) 20 13 Toughness Index ( I t ) 14 Consistency Index ( I C ) 15 Soil Classification 16 1.65 1.37 CH Activity (A) 0.58 Since (It) > 1.0 Soil nor friable at Plastic state. Since ( I C ) >1.0 Very Stiff Clay Of High Compressibility A < 0.75 Soil is Inactive UCC lies (200-400 17 OMC 23.5% 18 MDD 1.53 g/cc 19 Unconfined 223.05 compressive strength KN/m 2 KN/m 2 ) Soil is Very Stiff 20 Cohesion 111.52 KN/m 2 Table 2. Properties of Quarry Dust, Fly ash and Waste Paper Sludge Ash S.NO PROPERTY RESULT QD FA WPS A 1 Specific 1.052 2.57 2.14 Gravity 2 % of Gravel 0 0 0 3 % of Sand 97 0.3 20.6 4 % of silt and 79.4 3 99.7 clay 5 % of silt 0 79.76 73.048 6 % of clay 0 19.94 6.352 7 Not - OMC (%) 24 applicable 8 MDD (g/cc) - 1.65-236
S.NO ISSN: 2277-3754 Table 3. Chemical Composition of Fly ash (FA) Table 5. Laboratory test results of treated soil (Soil + QD) Chemical % by S.n PROPERT composition weight o Y 1 SiO 2 +Al 2 O 3 +Fe 2 O 3 Requirement s as per IS 3812: 2000 (Part 1) 90.5 70.00 (min) 2 CaO 3.6 5.0 (max) 3 MgO 1.91 5.0 (max) 4 2- SO 4 1.80 2.75 (max) 5 Na 2 O 1.50 2.0 (max) 6 Loss of ignition 2.0 5.0 (max) The chemical composition of FA (Class F) obtained directly from METTUR THERMAL POWER PLANT. The following elements of chemical composition of WPSA were analyzed by EDAX graph as shown in Fig 7. Fig 7 EDAX graph Table 4. Chemical Composition of Waste Paper Sludge Ash (WPSA) S.NO ELEMENT Chemical composition (%) 1 Carbon, C 8.98 2 Oxygen, O 53.01 3 Sodium, Na 0.77 4 Magnesium, Mg 3.36 5 Aluminium, Al 2.55 6 Silica, Si 6.51 7 Sulphur, S 0.46 8 Chlorine, Cl 0.87 9 Calcium, Ca 22.78 10 Iron, Fe 0.71 The Elements of chemical composition of WPSA was analyzed by using EDAX TEST. The results are obtained from Karunya University, coimbatore. Table 4. Characteristics of Polypropylene Fibre (PF) S.NO PROPERTIES RESULT 1 Length (mm) 6 2 Diameter (mm) 0.04 3 Aspect ratio ( L / D ) 150 4 Density (g/cc) 0.91 5 Tensile strength 450 ( Mpa ) 6 Elongation break (%) 15-25 RESULTS QD (%) 10 20 30 4 0 1 DFS (%) 40 30 10 0 0 2 Liquid 42 39. 36 3 29 limit (%) 4.8 3.4.7 3 Plasticity 17 14. 11 8. 4. index (%) 4.8 4 7 4 Shrinkage 16. 17. 17 1 18 Limit (%) 7 1.4 7.9.6 5 OMC (%) 20. 19. 18 1 16 54 51.3 6.2.2 6 MDD 15. 16. 17 1 18 (KN/m 3 ) 8 7.2 7.6.2 7 UCC 235 247 27 2 21 (KN/m 2 ). 2.9 5 51 7 8 Cohesion 117 123 13 1 10 (KN/m 2 ).6.9 7 25 8 Table 6. Laboratory test results of treated soil (Soil + FA) S.n o Property RESULTS FLY ASH (%) 10 20 30 40 50 60 1 DFS (%) 50 30 20 10 0 0 2 Liquid 53 49 45 39 34 32. limit (%).8.2 5 3 Plasticity 28 24 20 14 9. 7.5 index (%).8 20 4 Shrinkage 11 13 14 17 19 21 limit (%).4.0 5 OMC (%) 27 29 30 34 33 31..2.6.2.4.5 2 6 MDD 19 21 21 21 21 21. (KN/m 3 ).9.1.4.5.3 1 7 UCC 23 24 26 28 23 21 (KN/m 2 ) 0 6 3 4 4 9 8 Cohesion 11 12 13 14 11 10 (KN/m 2 ) 5 3 1 2 7 9 Table 7. Laboratory test results of treated soil (Soil + WPSA) S.n o Property RESULTS WPSA (%) 2 4 6 8 10 12 1 DFS (%) 50 40 30 30 20 10 2 Liquid 53 48 43 38 33 31. limit (%).6.7.6 4 3 Plasticity 28 23 18 13 8. 6.4 index (%).6.7 6 4 Shrinkage 11 14 15 17 19 21. limit (%).5.4.9.6.8 6 5 OMC (%) 24 26 29 30 32 33..6.7.2.1.2 0 6 MDD 21 21 21 21 21 21. (KN/m 3 ).3.1.6.8.5 3 7 UCC 23 24 25 27 23 21 (KN/m 2 ) 4 3 6 2 3 6 8 Cohesion 11 12 12 13 11 10 (KN/m 2 ) 7 1 8 6 6 8 50 237
Table 8. UCC test results for soil using QD, FA and WPSA with PF S.NO Soil Unconfined compressive Description strength (KN/m 2 ) Fibre content (%) 0.5 1.0 1.5 2.0 1 Soil+ 30%QD 289.1 302.7 259.6 221.2 2 Soil +40% FA 301.2 315.5 268.3 237.7 3 Soil+8%WPS A 285.4 263.8 230.9 204.3 DIFFERENTIAL FREE SWELL INDEX TEST AND ATTERBERG S LIMIT TEST For Quarry dust The variation in DFS and Atterberg s limit test for various % of QD is shown in Fig 8. Fig 10. DFS and Atterberg s limit for various (%) of WPSA. COMPCATION TEST FOR QUARRY DUST The variation in OMC and MDD for Quarry dust is shown in Fig 11. Fig 8. DFS and Atterberg s limit test for various % of QD DIFFERENTIAL FREE SWELL INDEX TEST AND ATTERBERG S LIMIT TEST for Fly ash The variation in DFS and Atterberg s limit test for various % of FA is shown in Fig 9. Fig 11. Variation in OMC and MDD for QD COMPCATION TEST FOR FLYASH The variation in OMC and MDD for Fly ash is shown in Fig 12. Fig 9. DFS and Atterberg s limit test for various % of FA DIFFERENTIAL FREE SWELL INDEX AND ATTERBERG SLIMITTEST for (WPSA) The variation in DFS and Atterberg s limit test for various % of WPSA is shown in Fig 10. Fig 12. Variation in OMC and MDD for FLY ASH 238
COMPCATION TEST FOR WASTE PAPER SLUDGE ASH (WPSA) The variation in OMC and MDD for Waste Paper Sludge Ash is shown in Fig 13. MDD = 2.18 g/cc Fig 13.Variation in OMC and MDD for WPSA UCC TEST FOR SOIL USING QD, FA, WPSA The variation in Shear strength for QD, FA and WPSA is shown in Fig 14. Fig 14. Variation in Shear strength for QD, FA, WPSA UCC TEST FOR SOIL USING QD, FA, WPSA WITH POLYPROPYLENE FIBRE (PF) The variation in Shear strength for QD, FA and WPSA with Polypropylene Fibre is shown in Fig 15. Fig 15. Variation in Shear strength for QD, FA, WPSA with Polypropylene Fibre VI. CONCLUSION Based on the experimental investigations on stabilization of soil, the following conclusions are drawn. 1. The free swell index of untreated soil was 70%. It has decreased to 10% at 30% QD, 40% FA and 12% WPSA. The free swell reaches zero beyond this. 2. The liquid limit (LL) of untreated soil was 58%. It has decreased to 36.8% at 30% QD. On further addition of QD, LL has finally reduced to 29.7%. LL has decreased to 39% at 40% FA. On further addition of FA, LL has finally reduced to 32.5%. Similarly LL has decreased to 38% at 8% WPSA. On further addition of WPSA, LL has finally reduced to 31.4%. 3. The plasticity index (PI) of untreated soil was 33%. It has decreased to 11.8% at 30% QD. On further addition of QD, PI has finally reduced to 4.7%. Similarly it has decreased to 14% at 40% FA. On further addition of FA, PI has finally reduced to 7.50%. Similarly PI has decreased to 13% at 8% WPSA. On further addition of WPSA, PI has finally reduced to 6.4%. 4. The shrinkage limit (SL) of untreated soil was 8.38%. It has increased to 17.42% at 30% QD. On further addition of QD, SL has finally increased to 18.66%. Similarly it has increased to 17.92% at 40% FA. On further addition of FA, SL has finally increased to 21.47%. Similarly SL has increased to 17.54% at 8% WPSA. On further addition of WPSA, SL has finally increased to 21.6%. 5. The OMC of untreated soil was 23.5%. The addition of QD decreases the OMC from 23.50% to 16.27% at 50% QD. Similarly OMC has increased to 34.40% at 40% FA. On further addition of FA, OMC has finally decreased to 31.29% at 60% FA. The addition of WPSA increases the OMC from 23.50% to 33.01% at 12% WPSA. 6. The MDD of untreated soil was 1.53g/cc. The addition of QD increases the MDD from 1.53g/cc to 1.82g/cc at 50% QD. MDD has increased to 2.15 g/cc at 40% FA. On further addition of FA, MDD has finally decreased to 2.11g/cc. Similarly MDD has increased to 2.18 g/cc at 8% WPSA. On further addition of WPSA, MDD has finally decreased to 2.13g/cc. 7. The unconfined compressive strength of untreated soil was 223.05 KN/m 2. The addition of QD has increased the UCC strength from 223.05 KN/m 2 to 275.34 KN/m 2 at 30%QD. The percentage increase in QD is 23.4%. The addition of FA has increased the UCC strength from 223.05 KN/m 2 to 284.71 KN/m 2 at 40% FA. The percentage increase in FA is 27.64%. The addition of WPSA has increased the UCC strength from 223.05 KN/m 2 to 271.64 KN/m 2 at 8% WPSA. The percentage increase in FA is 21.78%. 8. The unconfined compressive strength of soil with 30% QD and 1% fibre has increased from 223.05 KN/m 2 to 302.73 KN/m 2. The percentage increase is 35.7%. 239
9. The unconfined compressive strength of soil S.NO EXPERIMENTS IS SPECIFICATION with 40% FA and 1% fibre has increased from 223.05 1 Determination of Water IS: 2720 (Part 2)- 1973 KN/m 2 to 315.50 KN/m 2. The percentage increase is Content 41.44%. 2 Determination of Specific IS: 2720 (Part 3/ SEC -I)- 10. The unconfined compressive strength of soil gravity 1980 with 8% WPSA and 0.5% fibre has increased from 3 Determination of Grain IS: 2720 (Part 4)- 1985 223.05 KN/m 2 to 285.43 KN/m 2. The percentage increase Size analysis is 27.96%. 4 Determination of IS: 2720 (Part XL)- 1997 11. The addition of Quarry dust, Fly ash, Waste Differential Free Swell paper sludge ash reduces the compressibility and swells 5 Determination of Liquid IS: 2720 (Part 5)- 1985 potential of soil and also increases the shear strength. The and Plastic limits. necessity of adding polypropylene fibre is to avoid the 6 Determination of IS: 2720 (Part 6)- 1972 crack formation and also to reduce the settlement of soil. Shrinkage limit Thus the stabilization of Coimbatore clay seems to be 7 Determination of water IS: 2720 (Part 7)- 1980 more economical and free from pollution due to addition content Dry density of these industrial wastes to the soil. Relation using light REFERENCES [1] Akshaya Kumar Sabat (2012) Effect of Polypropylene fibre on Engineering properties of Rice Husk Ash Lime Stabilized Expansive Soil, Electronic Journal of Geotechnical Engineering, Vol. 17, Bund.E, pp. 651-659. [2] Norazlan Khalid, Mazidah Mukri and Faizah Kamarudin (2012), Clay soil stabilized using Waste Paper Sludge Ash (WPSA) Mixtures, Electronic Journal of Geotechnical Engineering, Vol. 17, Bund. I, pp. 1215-1225. [3] Pradip D. Jadhao and Nagarnaik, P.B (2008), Influence of Polypropylene Fibres on Engineering Behavior of Soil Fly ash Mixtures for Road Construction, Electronic Journal of Geotechnical Engineering, Vol. 13, Bund.C, pp. 1-11. [4] Quardi Syed Ghausuddin and Shubhada Sunil Koranne (2011) Evaluation of Soil - Quarry Dust Mixtures Reinforced with Polypropylene Fibres, Electronic Journal of Geotechnical Engineering, Vol. 16, Bund. I, pp. 1007-1016. AUTHOR BIOGRAPHY compaction 8 Determination of unconfined compression test IS: 2720 (Part X)- 1991 Dr.P.D.ARUMAIRAJ ASSOCIATE PROFESSOR AND HEAD DEPARTMENT OF CIVIL ENGINEERING (SOILS) GOVERNMENT COLLEGE OF TECHNOLOGY COIMBATORE, TAMILNADU, INDIA R.VINOTHKUMAR PG STUDENT M.E. GEOTECHNICAL ENGINEERING GOVERNMENT COLLEGE OF TECHNOLOGY COIMBATORE, TAMILNADU, INDIA. APPENDIX INDIAN STANDARD SPECIFICATION The Laboratory test procedure for soil is followed as per IS Specification given below. 240