An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 80/100 Grade Bitumen

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1 IJIRST International Journal for Innovative Research in Science & Technology Volume 2 Issue 9 February 21 ISSN (online): An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen Ashish Rangare Scholar Department of Civil Engineering Jabalpur Engineering College Jabalpur Anil Singhai Associate Professor Department of Civil Engineering Jabalpur Engineering College Jabalpur Abstract In flexible pavement construction at present days the development of new roads is being modified and the ever increasing population has raised the vehicular density from last few decades. Scrap tyres are one of the ingredient of pollution and also the disposal of scrap tyre is a problem in present days because it is not eco-friendly and non-biodegradable. The recycled scrap tyres are no longer suitable for use on vehicles due to wear or irreparable damages so reuse of scrap tyre rubber is not economical for the business purpose. In India scrap tyre rubber is used for modifying bitumen, the three grades of bitumen is developed CRMB-, CRMB- and CRMB- but it depend on overall system of collecting scrap tyre, due to this cost of CRMB is high as compared to 3/4,/7 and 8/1 grade of bitumen. In this study locally available scrap tyre crumbed rubber is added in percent of 4%, %, 8%, 1% and 12% by weight of 8/1 grade of bitumen at 1ºC temperature because of it will be easily generated at the time of flexible pavement construction. Keywords: CRMB, Bitumen, CRM I. INTRODUCTION India is seventh largest country in the world and second in population here large road network for transportation. In India flexible pavement is preferred due to low initial cost and maintenance cost. The construction of flexible pavement bitumen is used as binder and also its demand is increase due to urbanization hence the modification of bitumen requires for better performance and also makes it economical. Another thing is increasing population as soon as vehicles demand is also increasing so it leads to generation of huge quantity of waste tyre. The waste tyre is not eco-friendly and non-biodegradable, this reason makes it difficult to dispose so we can solve the problem of disposal and reduce the demand of bitumen by using of waste tyre as crumb-rubber in Bitumen modification helps in achieving better performance of wearing courses. Properties of modified bitumen depend upon type and quantity of modifier used and process adopted for their manufacture. The advantages of modified bitumen can include one or more of the following for road works: 1) Lower susceptibility to temperature variations 2) Higher resistance to deformation at high pavement temperature 3) Delay of cracking and reflective cracking 4) Better age resistance properties ) Better adhesion between aggregates and binder ) Higher fatigue life of mixes 7) Overall improved performance II. LITERATURE REVIEW Many studies have been carried out on the use of crumb rubber for modification of bitumen. Mohammed Sadeque et. al an experimental study on effect of waste tyre rubber on /7 grade bitumen. The crumb rubber modified bitumen is prepared in the laboratory, taking CR content 2%, 4%, %, 8% and 1% by weight of bitumen. It is found that the physical and strength properties of the binder are improved due to the modification by waste tyre rubber. Baha Vural Kök et al. (211) concluded that both SBS and CR modified bitumen exhibited reduced temperature susceptibility with increasing additive contents. However, this trend was more pronounced for the SBS modified bitumen. Praveen Kumar (29) based on his laboratory study on rheological properties of crumb rubber modified bitumen found that the physical properties like penetration, ductility and softening point are improved due to addition of crumb rubber. It is also found that complex modulus increases with increase in modifier content but the phase angle decreases with increase in modifier. The increase in complex modulus and decrease in phase angle is an indication of higher resistance to deformation as compared to unmodified bitumen. Present investigation of the work is to investigate the effects of scrap tyre crumbed rubber on the strength and stability characteristics of BC mix which is used for surface course in road construction. In present investigation bituminous concrete [BC] of grade ΙΙ is selected. III. METHODOLOGY ADOPTED FOR PRESENT STUDY 1) To conduct the Standard tests for the properties of plain bitumen. All rights reserved by 1

2 An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen 2) To determine the optimum binder content for plain mixes 8/1, CRMB, and modified bitumen by Marshall Stability method. 3) To use scrap tyre crumbed rubber as additive and blended with bitumen and test all the basic test parameters. IV. MATERIAL CHARACTERIZATION Study involves the use of materials like Bitumen, Aggregate and scrap tyre crumbed rubber. Bitumen: Bitumen is a material which is a by-product of petroleum refining process. It is a highly viscous at temperature above 1 degrees Celsius and is solid at room temperature. Table 1 Properties of bitumen used in present study Serial no. Properties Grade Test methods Crmb 8/1 1 Penetration at 2 c 7 9 Is: Softening point ºc 1 41 Is: cm Is: Flash point, ºc Is: Fire point, ºc Is: Specific gravity of bitumen Is: Aggregates: An aggregate which has good and sufficient strength, hardness, toughness and soundness have to be chosen. Crushed aggregates produce higher stability. Basic physical parameters of aggregates are found using various tests as tabulated below. Table 2 Sr.no Aggregate tests Test results obtained 1 Specific gravity of coarse aggregates Specific gravity of fine aggregates Specific gravity of dust and filler 2.9 and 1.2 Scrap Tyre Crumbed Rubber: A type of rubber that has been extensively used to modify bitumen is crumb rubber obtained from used vehicle tyres and which is indeed a waste material. These modified materials, popularly described as crumb rubber modified (CRM) bituminous materials, have the added environmental benefit of recycling scrap tyres that would otherwise be stockpiled or used in landfills. The use of recycled scrap tyres in asphalt mixture applications is not a recent development with reclaimed tyre crumb being used in the asphalt industry for over 3 years reclaimed tyre crumb can be incorporated into asphalt mixtures using two different methods, referred to as the wet and dry process. In the wet process, rubber and bitumen are digested together at high temperature to produce a crumb rubber binder. The crumb rubber binder is added to aggregate in a mixing plant in the same way as any other binder. In the dry process, however, dry rubber particles are added to aggregate and bitumen in a pugmill or drum mixer at the asphalt mixing plant. The rubber is usually mixed with the aggregate prior to bitumen addition but is still considered part of the binder. According to Oliver (2), the wet process has the advantage that the binder properties are better controlled, while the dry process is easier in terms of the logistics for marketing. Selection of Aggregate Gradation: Selection of proper gradation for the mix is one of the most important parameter. Ministry of road transport [MoRTH] has given some of the grading specifications for all the bituminous and non-bituminous layers used in road construction. In this investigation bituminous concrete [BC] which is considered as the wearing course or the surface course is selected. There are two gradations for bituminous concrete layers Grade I and grade II. As per Ministry Of Road Transport [MoRTH] specification bituminous concrete of mix designation Grade I, nominal aggregate size of 19mm and layer thickness of -mm is selected. Grading specification for bituminous concrete course is given in table. Table 3 Mix designation Nominal aggregate size Grading 2 Layer thickness 13mm 3-4mm Optimize Grading IS sieve(mm) Cumulative % by weight of total aggregate passing All rights reserved by 11

3 An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen Bitumen content, % by weight of total mixture.-7. V. LABORATORY TESTS Test on Bitumen: Standard tests on bitumen like penetration, softening point, ductility and flash and fire point were conducted by using appropriate apparatus. Tests on Mixes: Test on bituminous mixes for various properties like stability, flow value, bulk density and optimum binder content were conducted by using Marshall Stability apparatus. The properties of bituminous mix mainly depends on aggregate gradation, binder content, method of compaction and method adopted for compaction and temperature during compaction. VI. METHOD ADOPTED FOR ADDING SCRAP TYRE CRUMBED RUBBER TO THE MIX Scrap tyre crumbed rubber is blended with hot bitumen at 1ºC. Powerful mechanical stirrer is required to get effective mixing. The wet process is adopted in adding scrap tyre crumbed for bitumen. Analysis of the Data: Marshal moulds were prepared for different percentages of plain bitumen by varying the bitumen percentage from % % by increment of.%. The specimens were kept for 24hrs and then were de moulded. Marshall Stability test was conducted and parameters like flow value, bulk density, percentage air voids, voids filled with bitumen (VFB) and voids filled with mineral aggregates (VMA) were calculated. The optimum bitumen content, maximum bulk density and 4% volume of voids for bitumen grade 8/1, CRMB and crumbed rubber modified bitumen were calculated using the above properties. Also maximum stability was evaluated. Marshall Stability method was also conducted by adding scrap tyre of varying percentage from -12% for the know binder content of both 8/1 grade bitumen. The maximum stability attained for a particular percentage of plastic is noted down. Parameters used for calculation: Percentage weight of bitumen by weight of aggregate, W4 = % to % Apparent specific gravity of coarse aggregate, G1 = 3.17 Apparent specific gravity of fine aggregate, G2 = 2.98 Apparent specific gravity of filler, G3 = 2.9 Apparent specific gravity of bitumen, G4 Plain 8/1 grade bitumen, G4 = 1.1 CRMB grade bitumen, G4 = 1.1 Requirements of morth specifications for bituminous concrete pavement layer grade ιι Table 4 Type of bitumen Plane bitumen (8/1) For CRMB Minimum stability kn at C 9KN 9KN flow Compaction level (Number of blows) 7 7 Percent air voids 3-3- Percent voids in mineral aggregate (VMA) 14(min) 14(min) Percent voids filled with bitumen (VFB) -7-7 Properties of bituminous mixes The following properties were obtained from the laboratory studies on Bituminous Concrete Marshall Stability value (kn) Flow value (mm) Bulk density (gm/cc) Percent air voids in total mix (Vv) Voids filled with bitumen (VFB) Voids filled with mineral aggregates (VMA) All rights reserved by 12

4 An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen VII. RESULTS OF 8/1 GRADE AND CRMB GRADE AT %,.%, AND % Table TYPES OF 8/1 CRMB % of bitumen %.% % %.% % Gb STABILITY FLOW Vv (%) VMA (%) VFB (%) Results of obc for 8/1 Grade Bitumen: Maximum stability = 9.91KN, at bitumen content = % Maximum bulk density = gm/cc, at bitumen content = % Percent air voids =.18% at bitumen content = % Percent of VMA = 8.47% at bitumen content = % Optimum bitumen content of /7 grade bitumen = % Results of OBC for Crmb Grade Bitumen: Maximum stability = KN, at bitumen content = % Maximum bulk density = gm/cc, at bitumen content = % Percent air voids =.412% at bitumen content = % Percent of VMA = 7.71% at bitumen content = % Optimum bitumen content of CRMB grade bitumen = % Properties of Bituminous Mix After Adding Scrap Tyre Crumbed Rubber At 4% To 12% By Weight Of 8/1 Grade Bitumen Table - TYPES OF % of bitumen 4% CR BY WT. OF % CR BY WT. OF 8% CR BY WT. OF 1% CR BY WT. OF 12% CR BY WT. OF %.% % %.% % %.% % %.% % %.% % Gb STABILIT Y FLOW Vv (%) VMA (%) VFB (%) Relation between Bulk Density and Percent of Crumbed Rubber: Fig. 1: Percent of crumbed rubber All rights reserved by 13

5 Relation between Stability and Percent of Crumbed Rubber: An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen Fig. 2: Percent of crumbed rubber Relation between Voids Filled with Bitumen (VFB) And Percent of Crumbed Rubber: Relation Between Flow and Percent of Crumbed Rubber: Fig. 3: Percent of crumbed rubber Fig. 4: Percent of crumbed rubber All rights reserved by 14

6 Relation between Voids Ratio (VV) And Percent of Crumbed Rubber: An Experimental Study on Effect of Scrap Tyre Crumbed Rubber on 8/1 Grade Bitumen Fig. : Percent of crumbed rubber VIII. RESULTS AND CONCLUSION In this study by using the same material i.e. % bitumen obtain the comparable results, which are summarised below according requirements of Morth Specifications in tabular form. Table 7 Type of bitumen 8/1 bitumen CRMB 8/1 bitumen + 1% CR by Wt. of bitumen Gb Stability Flow By this study we concluded, of total quantity of bitumen that replacing by 1% of crumbed rubber, we even got the better results, increase in stability in bituminous mix grade ΙΙ and comparatively higher to 8/1 grade bitumen and modified bitumen CRMB by this can be used in highway construction for better stability for the appropriate traffic. REFERENCES [1] Abdelkader Chaala, Christian Roy and Abdellatif Ait-Kadi (199), Rheological Properties of Bitumen Modified With Pyrolytic Carbon Black, Fuel, Vol. 7, No. 13, pp [2] Airey G D, Singleton T M and Collop A C (22), Properties of Polymer Modified Bitumen after Rubber-Bitumen Interaction, journal of materials in civil engineering, pp [3] Baha Vural Kök and Hakan Çolak (211), Laboratory Comparison of The Crumb-Rubber and SBS Modified Bitumen and Hot Mix Asphalt, Construction and Building Materials, Vol. 2, pp [4] Fereidoon Moghadas Nejad, Pedram Aghajani, Amir Modarres and Hasan Firoozifar (212), Investigating The Properties of Crumb Rubber Modified Bitumen Using Classic and SHRP Testing Methods, Construction and Building Materials, Vol. 2, pp [] Hak-Seo Kim, Soon-Jae Lee and Serji Amirkhanian (21), Rheological Investigation of Rubber Modified Asphalt Binders, KSCE Journal of Civil Engineering, Vol. 14, No., pp [] Praveen Kumar H C, Mehndiratta K and Lakshaman Singh (29), Rheological Properties of Crumb Rubber Modified Bitumen-A Lab Study, Journal of Scientific and Industrial Research, Vol.8, September, pp [7] "Specifications" would refer to the "Specifications for road and bridge works" (4th revision) published by the Indian roads Congress August'21, on behalf of the Government of India, Ministry of Road Transport & Highway (Roads Wing). [8] IRC: SP: 3-21 Guidelines on use of modified bitumen in road construction (second revision) Indian roads congress 21. All rights reserved by 1