A STUDY ON USE OF POLYPROPYLENE FIBRE AND WASTE TYRE MATERIALS IN CONCRETE FOR ROAD PAVEMENTS

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1 A STUDY ON USE OF POLYPROPYLENE FIBRE AND WASTE TYRE MATERIALS IN CONCRETE FOR ROAD PAVEMENTS Mr. Shishupal T. Dhabekar 1, Mr. Ganesh L. Gawhare 2, Mr. Rajkumar K. Bharne 3, Mr. Mahesh S. Lengure 4, Mr. Vishnu P. Sawsundar 5 Student B.E. (Civil Engineering), Agnihotri College of Engineering, Wardha, Maharashtra dhabekarshishupal@gmail.com ganeshgawhare111@gmail.com rajkumarbharne@gmail.com maheshlengure@gmail.com vpsawsundar@gmail.com ABSTRACT Concrete is strong in compression but weak in tension and brittle also. Cracks also start forming as soon as the concrete is placed. These 3 drawbacks don t permit the use normal concrete in pavements as they lead to lack of ductility along with fracture and failure. These weaknesses in concrete can be mitigated by using fibers as reinforcement in the concrete mix. Waste materials in the form of polypropylene and tires cause environmental pollution which leads to various health problems. Polypropylene and waste tires can be recycled and used effectively in the concrete as reinforcement in the fiber form. Polypropylene is a synthetic hydrocarbon polymer which can improve the ductility, strength, shrinkage characteristics etc. This paper deals with the effects of addition of Polypropylene fiber on the properties of concrete. Polypropylene and tire fibers were cut into the size of 30mm x 6mm and they were used 1.5% each by volume. Grade of concrete used were M30, M35 and M40. IRC 44:2008 was followed for the design of concrete mix. In this study, the results of the Strength properties of Polypropylene fiber reinforced concrete have been presented. Theoretical analysis of deflection was carried out by the help of energy methods. Practical values were verified with the theoretical values within the permissible limits. Finally it can be concluded that polypropylene and tire can be used effectively in reinforced cement concrete. At present the disposal of waste tyres is becoming a major waste management problem in the world. It is estimated that 1.2 billions of waste tyre rubber produced globally per year. It is estimated that 11% of post consumer tyres are exported and 27% are sent to landfill, stockpiled or dumped illegally and only 4% is used for civil engineering projects. Hence efforts have been taken to identify the potential application of waste tyres in civil engineering projects. In this context, our present study aims to investigate the optimal use of waste tyre rubber as coarse aggregate in concrete composite. Keywords: polypropylene fibers, Tyre, Compressive Strength, Concrete Mix, coarse aggregate, fine aggregate, mechanical properties of concrete, fiber specimen. INTRODUCTION These fibers are manufactured using conventional melt spinning. Polypropylene fibers are thermo plastics produced from Propylene gas. Propylene gas is obtained from the petroleum by products or cracking of natural gas feed stocks. Propylene polymerizes to form long polymer chain under high temperature and pressure. However, polypropylene fibers with controlled configurations of molecules can be made only using special catalysts. Polypropylene fibers are hydrophobic, that is they do not absorb water. Therefore, when

2 placed in a concrete matrix they need only be mixed long enough to insure dispersion in the concrete mixture. The manufacturers of fibrillated fibers recommend their products for the following purposes in paving: to reduce plastic shrinkage and permeability, to increase impact resistance, abrasion resistance, fatigue, and cohesiveness (for use in slip forming and on steep inclines), and to provide a cost effective replacement for welded wire fabric (WWF). it has been established that fiber introduced concrete has the property of obtaining extra strength in flexure, compression, fatigue and impact, it can successfully be reinforced in concrete to get more strength as a whole and use it for pavements as concrete in itself is weak in tension and impact. Fibers in combination with concrete also results in a mix with improved early resistance to plastic shrinkage cracking, reduced water absorption, greater impact resistance, enhanced flexural strength and tensile strength of concrete and thereby protects the concrete from drying shrinkage cracks. In ordinary concrete, where vibration is necessary, the best and most acceptable method for preventing cracks formations caused by paste contract is by using fibers. Waste tyre management is a serious global concern. Millions of waste tyres are generated and dumped or burned every year, often in an uncontrolled manner, causing a major environmental and health problem. Tyres are durable and not naturally biodegradable. Waste tyres will remain in dump sites with little degradation for a long time, leads to environmental hazard. Therefore, recycling of waste tyre plays a vital role in concrete. The primary objective of this study was to evaluate the reuse potential of crumb rubber in concrete mixtures for pavement applications. Scrap tyre rubber chips can be also used as coarse aggregate with the replacement of conventional coarse aggregate. The feasibility of incorporating scrap tyre rubber chips as coarse aggregate in concrete mixes and determine the change in the properties after the incorporation of the rubber into the concrete mix is to be investigated. Due to replacement of the aggregates by rubber particles, the weight was reduced. Due to non-uniform distribution of rubber particles in the concrete, non- homogenous samples may produce, which in turn results in reduction in concrete strength. The stiffness of rubber is lower as compared to stiffness of coarse aggregate, the presence of rubber particles in concrete reduces the concrete mass stiffness and also decreases load bearing capacity of concrete. LITERATURE REVIEW According to Balaguru (1988) the uniaxial compression test is normally used to evaluate the behavior of concrete in compression. This produces a combination of shear failure near the ends of the specimen with lateral swelling of the unconfined central section accompanied by cracking parallel to the loading axis when the lateral strain exceeds the matrix cracking strain in tension. Fibers can affect these facets of uniaxial compressive behavior that involve shear stress and tensile strain. This can be seen from the increased strain capacity and also from the increased toughness (area under the curve) in the post-crack portion of the stress-strain curve. Khajuria and Balaguru, (1989).in some instances, if more water is added to fiber concrete to improve its workability, a reduction in compressive strength can occur. This reduction should be attributed to additional water or due to an increase in entrapped air, not fiber addition. Johnston and Skarendahl, (1992). The addition of fibers up to a volume fraction of 0.1% does not affect the compressive strength. When tested under compression, failure occurs at or soon after the peak load providing very little toughness. It is found that the fibers have very little effect on compressive strength calculated from the peak load, and both slight increase and

3 decrease in strength have been reported with increase in fiber content. The decrease in strength is mostly reasoned due to incomplete consolidation. Alhozaimy, A.M., et al (1995) carried out experimental investigations on the effects of adding low volume fractions (<0.3%) of calculated fibrillated polypropylene fibres in concrete on compressive flexural and impact strength with different binder compositions. They observed that polypropylene fibres have no significant effect on compressive (or) flexural strength, while flexural toughness and impact resistance showed increased values. They also observed that positive interactions were also detected between fibres and pozzolans. [1] Kolli Ramujee (2013) The interest in the use of fibers for the reinforcement of composites has increased during the last several years. A combination of high strength, stiffness and thermal resistance favorably characterizes the fibers. In this study, the results of the Strength properties of Polypropylene fiber reinforced concrete have been presented. The compressive strength, splitting tensile strength of concrete samples made with different fibers amounts varies from 0%, 0.5%, 1% 1.5% and 2.0% were studied. The samples with added Polypropylene fibers of 1.5 % showed better results in comparison with the others. [2] Milind V. Mohod (2015) This paper presents an experimental study on performance of polypropylene fiber reinforced concrete. In this study deals with the effects of addition of various proportions of polypropylene fibers on the properties of High strength concrete (M30and M40 mixes). An experimental program was carried out to explore its effects on compressive, tensile, flexural strength under different curing condition. The main aim of the investigation program is to study the effect of Polypropylene fiber mix by varying content such as 0%,0.5%,1%,1.5% & 2% and finding the optimum Polypropylene fiber content. A notable increase in the compressive, tensile and flexural strength was observed. However, further investigations were highly recommended and should be carried out to understand more mechanical properties [Topcu, 1995]. Topcu in his study investigated the changes of the properties of rubberized concretes in terms of both size and amount of the rubber chips. The compressive strength when tested at 28 days was 29.50MPa, it was however shown that that with the addition of 15, 30 and 45% of coarse rubber chip, that value was reduced to 14.60, 8.91 and 5.51 MPa respectively. This represents a 51, 70 and 81 percent reduction in compressive strength of fiber reinforced concrete. Researchers have tried to gain different advantages from the use of waste tire in concrete. High-strength concrete (HSC) with silica fume was modified with different amounts of crumbed truck tires [Hernandez-Oliveres, et al 2003]. They were aiming to reduce the stiffness of HSC to make it compatible with other materials and building elements, unexpected displacement of building foundations and improving the fire performance of the buildings.

4 Materials Used The basic materials for mixing Concrete are required such as Cement, Sand, Aggregate and Tyre rubber Polypropylene fiber Cement: The cement used was Ordinary Portland cement (53Grade) with a specific gravity of Initial and final setting times of the cement were 69 min and 195 min, respectively. Sand: The River sand was used as fine Aggregate and conforming to Zone:III with specific gravity of 2.6, Bulk density of 1680 kg/m3. Aggregate: Coarse aggregate from stone crusher having a nominal maximum size of 20 mm was used. The specific gravity of coarse aggregate was 2.7. Tyre fibre: Tyre rubber aggregate. About 30 mm long waste tyre rubber pieces are obtained from local market; the pieces were cleaned with hot water and rinse with clean water. After drying under sun at open place, both faces of the tyre pieces were rubbed with hard wire brush to make surfaces as rough as can be done by hand. Polypropylene fibre:

5 The fibres used were fine polypropylene monofilaments.the fibers were supplied by Reliance Industry by name polypropylene. It is available in 3 different sizes i.e. 6mm, 12mm and 24 mm In the present investigation 12mm fiber length is used. Mix design: The Concrete mix design has been carried out for various proportions as per and arrived at final mix Proportion (cohesive) and mentioned in Table 1 was used for combining the initial materials, after mixing the initial Materials in the rotating mixer and adding the fibers. In this research the concrete samples were prepared with fiber ratios of 1.5% by volume. In order to have a proper mixture design as well as the least penetration, the applied aggregates were graded according to the. The ratio of water added to the cement was w/c = Table 1. The Raw materials used in the mix design Presented mix design Ingredients kg m 3 Water 197 Cement 395 Coarse 1152 Aggregate Fine Aggregate 597 W/C Ratio 0.50 Specific gravity 0.91 gr/cm3 Cut length 12mm Polypropylene Width crossing Circular Melting point c Water absorption 0 Cut length Of tyre 30*6mm Table 2. Physical characteristics of fibres Advantages of polypropylene and tyre mix concrete Avoid micro cracks in concrete Improved closed surface of concrete Excellent crack reduction in early-age concrete. Better concrete durability & reduced surface dusting. Improves impact and abrasion resistance. Improves mix cohesiveness. Reduces segregation of the mix.

6 Significant improvement in freeze-thaw cycle resistance. Saves time. Improves water migration. Reduces shotcrete rebound. Less concrete waste. The workability of the rubberised concrete increases with the increase in rubber content. This may be due to the lower water absorption capacity of the tyre chips. Due to lower water absorption capacity of the tyre chips, the good workability can be achieved with lower water cement ratio and hence may be useful for high performance concrete having low water cement ratio. This property may lead to the reduction in use of plasticizer and super plasticizer in those concrete. The use of rubberised concrete may be very much beneficial for a country like India where the problem of scrap tyre disposal is at the very initial stage. The rubberised concrete may be useful for the bases of foundation which in turn reduces the use of natural aggregates and hence mining. To be used in reinforced cement concrete, it needs further investigations and field tests. The unit weight of rubberised concrete decreases with the increase in tyre chips content and hence may be suitable for lightweight construction. The compressive strength of the concrete with tyre chips does not show any remarkable decrease upto 15% replacement of natural aggregate with tyre chips. It will offer an opportunity for new entrepreneurs to set up industries for production of tyre chips and hence help in saving our environment as well as employment generation. CONCLUSION: From the tests that I have performed I came to the following conclusions: 1. The polypropylene fibers (PPF) reduce early age shrinkage and moisture loss of the concrete mix even when low volume fractions of PPF are used. 2. From the result of this research, it was found that the use of fiber in the concrete decreases the workability of the fresh concrete Evidence of low workability was shown through the results of workability test obtained in standard slump test. It was concluded that the increasing percentage volume of fiber added into the concrete would lead the workability decreased. However it also reduced the bleeding and segregation in the concrete mixture. 3. It was also seen that the loss in weight and loss/gain in compressive strength of the cube specimens improved with age. Compressive strength of concrete increases with increase in fiber dosage up to 1.5%, then it starts decreasing. So the optimum percentage fiber found from research is found out to be 1.5%. 4. As per the current demand of construction industry new types of concrete are to be invented, which will satisfy the problems observed in traditional concrete. In this approach PPFRC will be a good substitute to meet the present demand of construction industry. 5. The finite element model clearly showed the development of micro cracks in the concrete. The model can be used to try and keep the formation of cracks to a minimum, thus increasing the strength at which concrete fails.

7 6. Waste tire modified concrete had lower compressive and tensile strength than the control mix. It was however shown that it was advantageous to use stiffer fibers as they had higher strengths. 7. The toughness of waste tire modified concrete was much greater than unmodified concrete. It was thus able to absorb more energy when loaded than the control sample. 8. The sample with waste tire as fibers performed better than those with chips thus, waste tires should be used as fibers instead of chips. REFERENCE: 1. Balaguru P.N. and Shah S.P., 1992, Fiber-Reinforced Cement Composites, McGraw- Hill Inc., New York, United State of America 2. Bentur A. and Mindess S., 1990, Fibre Reinforced Cementitious Composites, Elsevier Science Publishing Ltd., New York,United State of America. 3. A. M., Soroushian, P., & Mirza, F. (1996). Mechanical properties of polypropylene fiber reinforced concrete and the effects of pozzolanic materials. Cement and Concrete Composites, 18(2), Banthia N. and Dubey A., 2000, Measurement of flexural Toughness of Fibre-Reinforced Concrete Using Technique Part 2: Performance of various Composites. 5. BALAGURU, P., "Properties and Behavior of Fiber Reinforced Concrete," General Report, Technical Sessions 2, Proceedings of International Symposium on Fiber Reinforced Concrete, Volume III, 1987, pp Johnston, C.D., Steel-fiber-reinforced concrete pavement-second interim performance report, Fiber-reinforced Cement and Concrete, RILEM Symposium, 1975, pp Olivares Hernandez F, Barluenga G. High strength concrete modified with solid particles recycled from elastomeric materials. In: Konig G, Dehn F, Faust T, editors. Proceedings of the 6th international symposium on high strength/high performance, Leipzig, Germany, P Alhozaimy, A.M.; Soroushian, P.; and Mirza, F. (1996). Mechanical properties of polypropylene fiber reinforced concrete and the effect of pozzolanic materials. Cement and Concrete Composites, 18(2), Topcu, I.B., The Properties of rubberized. Cem. Concrete Res., 25: DOI: / (95)000143