STUDY OF THE BEHAVIOUR OF CONCRETE AFTER PARTIAL REPLACEMENT OF COARSE AGGREGATES BY WASTE TYRE RUBBER FIBRES AND ADDITION OF ADMIXTURES

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 4, April 2018, pp , Article ID: IJCIET_09_04_022 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed STUDY OF THE BEHAVIOUR OF CONCRETE AFTER PARTIAL REPLACEMENT OF COARSE AGGREGATES BY WASTE TYRE RUBBER FIBRES AND ADDITION OF ADMIXTURES Abhishek Tiwari Assistant Professor, Department of Civil Engineering, Jabalpur Engineering College, Jabalpur, India Bajrang Lal Panigrahi Lecturer, Department of Civil Engineering, Kirodimal Government Polytechnic, Raigarh, India Rustam Sahu M.Tech. Scholar, Department of Civil Engineering, Sagar Institute of Science Technology and Research, Bhopal, India ABSTRACT Concrete is the most widely used construction material in the world. Its high compressive strength and mould-ability into the desired shape has awarded it a separate place among all the construction materials. In the current exhaustive research work, waste tyre rubber fibres in different proportions 2%, 5% and 10% by weight of coarse aggregates have been used as partial replacement of coarse aggregates in concrete of grades M25 and M30 to carry out behavioral study of concrete. Later 1% superplasticizer admixture (Fosroc Conplast SP 430G8) by weight of cement is also added to study the change in behavior of tyre rubber fibre reinforced concrete. Specimens of 14 different proportions (from S1 to S14) were prepared from the combination of above ingredients. A series of tests like compressive strength test, flexural strength test and workability tests were performed on the designed specimens. From the study it is observed that the use of tyre rubber fibres reduces the compressive strength and workability of all the grades of concrete. Though its use in concrete enhances the flexural strength and hardness of concrete considerably. Use of 1% superplasticizer admixture by weight of cement is further proved beneficial to the concrete and has improved compressive strength, workability, flexural strength and hardness of tyre rubber fibre reinforced concrete. Keywords: Mix designing, Waste tyre rubber fibres, Conplast, Superplasticizer, Admixture editor@iaeme.com

2 Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures Cite this Article: Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu, Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures, International Journal of Civil Engineering and Technology, 9(4), 2018, pp INTRODUCTION Waste tyre rubber is produced in huge quantity as a waste and is not ensured to have appropriate disposal till now. Used tyres stands one of the significant parts of solid waste which usually causes a serious environmental problem. Recently European commission policies on the Land filling of Waste (Council Directive 1999/31/EC) barred the land filling of ragged tyres. Therefore, there is a decisive need to find substitute outlets for these used tyres. Also rubber had impressive properties that can be required to hold for practically partial replacement of both fine and coarse aggregate in concrete composite. We have done enough advancement in technology such that now we are producing concrete of strengths as high as 130 MPa. But the concrete is very low in toughness and flexural strength. So many attempts were already made in past to remove these drawbacks. Fibre reinforcement in concrete is one of the various methods that were used to improve toughness and flexural strength of concrete. Fibres like of obtained from jute, coir, plastic, steel, polypropylene, cotton, textiles, straws, rice husk, pulverized horse manure fiber, rubber, carbon fibres etc. were already used in so many research studies during recent years. A literature review into this space showed that there is still a comparatively restricted quantity of knowledge for a few properties of this sort of fiber and a few contradictory or inconclusive results across the present literature are there. For example, some researchers found that combination of rubber fibers of coarse grading results in higher compressive strength losses than fibers of finer grading (Eldin et.al., 1993, Topcu et.al., 1995 [6, 27]. Conversely others found the other trend. Moreover, sizes and kinds of rubber fibers used varied across researchers. It is so tough to achieve consistent conclusions regarding varied properties at varied set times returning from totally different literature sources. (Biel et.al., 1994) [4] concludes that concrete mix prepared with magnesium oxychloride cement and recycled tyre rubber in which aggregate was replaced by fine crumb rubber up to 25% by volume. The results showed that compressive and tensile strength tests results indicated that there is improved bonding when magnesium oxychloride cement is used. The researcher s states that structural applications could be possible if the rubber content is limited to 17% by volume of the aggregate. (Ilker et.al., 1995) [9] designated the concrete reformed by mixing with crumb rubber in coarse aggregate in the ratio of 15%, 30% and 45%. In this study, physical and mechanical properties were determined conferring to that the stress-strain diagram developed, resulting in investigating the toughness value, plastic energy and elastic energy capacities of the designed rubberized concrete. (Fattuhi et.al., 1995) [23] proposed composite comprised of the cement paste, mortar, and concrete (containing OPC or grade rubber) picked up from shredding scrap tyres. Density of several 32 concrete mixes varied between about 1300 and 2300 kg/m3. Compressive strength reduced by 70% when the proportion of rubber to total solid content by mass of concrete reached about 13% editor@iaeme.com

3 Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu (Gintautas et.al., 1998) [5] advised that, Rubber waste additives reduced both static and dynamic modulus of elasticity. Strains of the concrete with the same compressive strength with rubber waste from used tires (3.2% from aggregate by mass) deformations were 56%- 63% higher after the static loading, while set deformations after the unloading was 219%- 360% higher than for the none rubberized concrete. Cyclic loading of 20 cycles have no influence on the prismatic compressive strength of both concrete with and without rubber waste (3.2% from aggregate by mass) and ultimate strains on concrete failure load were 36%- 47% higher for concrete with tyre rubber waste additive. All these various analyses investigated the tensile, flexural and compressive strength of concrete with intercalary rubber fibers in several proportions, to assess its suitableness as a construction material and its impact on different mechanical properties of concrete. The results showed that despite an excellent loss in strength, this sort of concrete was acceptable for varied applications requiring medium to low compressive strength. The quantities of concrete created worldwide for such applications might make sure the viability of this product. Therefore, this sort of fiber reinforced concrete shows promise for turning into a further property resolution for tyre rubber waste management. However, for concrete with rubber fibers to be thought-about as a construction material there is minimum necessities of strength. This has recently been the topic of variety of studies however the realm continues to be comparatively less analysis than the employment of tyre within the different applications mentioned above. This research so geared toward performing arts a collection of consistent tests for a good vary of physical and mechanical properties and behaviour of concrete containing rubber fibers. These are given thoroughly within the different sections. 2. METHODOLOGY 2.1. Experiment Background In order to analyse the strength of concrete, the concrete is formed as plain cement concrete and fibre reinforced concrete moulded as cube of side 150 mm and beam of size (700X150X150) mm. The load is applied on the cube block under universal testing machine or compressive testing machine for the determination of compressive strength, 3rd point loading on beam for flexural strength (ASTM). For this a proper maintained proportion of tyre rubber is used in concrete to obtain the required mix. Using this maintained proportion of tyre rubber, the behaviour of fresh concrete has been determined Current Research Though rubberized concrete has proved its wide applications in numerous construction fields, still plenty of analysis must be done to live the elastic constants and mechanical properties of rubberized concretes by adding rubber in several volume proportions, water-cement ratios and in several forms like fiber chips, powder type, etc. in order that the acceptable strength will be explored. In this research the OPC (53grade), fine aggregates and coarse aggregates in combination of a mixture of 10mm and 20mm are used. The tyre rubbers were utilized in the shape of chips and fibers by partly substitution of the coarse aggregates in varying combination of 2%, 5%, 10% by weight of coarse aggregates. To enhance the strength characteristics and alternative mechanical properties of rubberized concrete, 1% superplasticizer (Fosroc Conplast SP 430G8) was added in cement. Admixtures maintain the workability of concrete and helps in increase of strength of mix by reduction in water cement ratio. Mix designing is editor@iaeme.com

4 Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures then done for different grades of concrete (M25 and M30) to study the behaviour of parameters (tyre fibres and superplasticizer) in concrete Materials Used Cement Ordinary Portland Cement confirming the requirements of IS 8112:1989 is used for the present experimental work. Ordinary Portland Cement of 53 grade used has following properties as mentioned in Table 1 below: Soundness Table 1 Properties of cement used in the study Physical Properties IS: Specifications Le Chat Expansion (mm) 4 Auto Clave Expansion (%) Fineness (m 2 /kg) 320 Standard Consistency (%) 32 Vicat initial setting time (minutes) 160 Vicat final setting time (minutes) 245 Compressive strength 3-days (MPa) 34 Compressive strength 7-days (MPa) 45.2 Compressive strength 28-days (MPa) 64.1 Specific gravity Aggregates The maximum nominal size of coarse aggregates is taken as 20 mm. Aggregates of size 10 to 12 mm is sought-after for structure having blocked-up reinforcement arrangement. Well graded cubical or rounded aggregates are desirable. The sample should be of uniform quality. Fine aggregates can be natural or manufactured. The grading must be uniform throughout the work. The locally available natural sand with 4.75 mm maximum size was used as fine aggregates, having specific gravity, fineness modulus bulk density water absorption as given in the Table 2. The coarse aggregates with 20 mm maximum size having specific gravity, fineness modulus and bulk density as below (also shown in Table 2) was used as coarse aggregates. Both fine aggregates and coarse aggregates validating to Indian Standard Specifications IS: Table 2 Properties of Aggregates used in the Study Physical Properties of Coarse and Fine Coarse Aggregates Aggregates Physical tests 10 mm 20 mm Fine Aggregates Specific gravity Fineness modulus (mm) Bulk density (kg/m 3 ) Water Absorption (%) editor@iaeme.com

5 Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu Rubber Rubber used for the research work has following properties as mentioned in Table 3 below: Table 3 Constituents of Rubber S.No Constituents of Tyre Percentage (%) 1 Natural Rubber 14 2 Synthetic Rubber 27 3 Carbon Black 28 4 Steel 14 5 Fabric, Filters, Accelerators, etc Admixture Superplasticizer is used for the present experimental work as an admixture in the concrete to increase the workability of fiber reinforced concrete and to ensure the water reduction so that the porosity of concrete can be reduced. Conplast SP430 G8 was used an admixture which is made available by Forsoc Chemicals (India) pvt. Ltd. which compiles with the BS: 5075 part 3 and code IS: The properties of admixture are mentioned in Table 4 below: Table 4 Constituents of Superplasticizer S.No Properties Remarks 1 Colour of Conplast Brown Solution 2 Specific gravity Chloride content Nil 2.4. Concrete Mix Design- Design of concrete mixes involves determination of the proportions of the given constituents namely cement, water, coarse aggregate and fine aggregate with admixtures. The concrete mix design is designated with the help of code IS: 10262:2009. The relative proportion of the fine and coarse aggregate are calculated from this mentioned code for both grades i.e. M25 and M30 at various fibre content and admixtures. Batch Designation Specimen Table 5 Concrete Mix Design Details Title Rubber Fiber (%) Admixture (%) S1 M25-C 0 0 S2 M25-2R 2 0 S3 M25-5R 5 0 S4 M25-10R 10 0 S5 M25-2RA 2 1 S6 M25-5RA 5 1 S7 M25-10RA 10 1 S8 M30-C 0 0 S9 M30-2R 2 0 S10 M30-5R 5 0 S11 M30-10R 10 0 S12 M30-2RA 2 1 S13 M30-5RA 5 1 S14 M30-10RA 10 1 Calculated Proportion (C:S:A) 1 : 1.93 : : 1.80 : : 1.70 : : 1.75 : editor@iaeme.com

6 Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures 3. RESULTS AND DISCUSSION 3.1. Results of Fresh Concrete Following results from Table 6 were obtained from the experimental study of workability test (slump cone and compaction factor tests) on different designed proportions of concrete mix. Both tests were performed to cross check the results and nature of graph obtained from each test. Table 6 Test results of slump test and compaction factor test Specimen Batch Title Slump Value (mm) Compaction Factor S1 M25-C S2 M25-2R S3 M25-5R S4 M25-10R S5 M25-2RA S6 M25-5RA S7 M25-10RA S8 M30-C S9 M30-2R S10 M30-5R S11 M30-10R S12 M30-2RA S13 M30-5RA S14 M30-10RA Figure 1 Variation in Slump values for different mix of M25 and M30 grades Figure 2 -Variation in Compaction Factor values for different mix of M25 and M30 grades editor@iaeme.com

7 Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu From the results (Table 6) and graphs (Figure 1 and Figure 2) obtained after performing slump cone test and compaction factor test we can easily observe that the workability of the concrete reduces with an increase in the rubber fibres content in the concrete mix. This may be because of the fact that rubber used for reinforcement generally absorbs water from the concrete mix and renders less available water for the lubrication purpose. It further increases friction between the ingredients of the mix. On the other hand, superplasticizer has increased the workability even at low water cement ratio. But after the addition of superplasticizer also we got the same nature of graph i.e. with increase in the rubber fibres content the workability of the mix reduces Results of Compressive Strength Test on cubes Results of Compressive Strength test for different grades of concrete cubes at 3 days, 7 days and 28 days are as shown in (Table 7) and (Figure 3 - Figure 5) below. Table 7 Test results of Compressive Strength Test Specimen Batch Title Average Compressive Strength (N/mm 2 ) 3 Days 7 Days 28 Days S1 M25-C S2 M25-2R S3 M25-5R S4 M25-10R S5 M25-2RA S6 M25-5RA S7 M25-10RA S8 M30-C S9 M30-2R S10 M30-5R S11 M30-10R S12 M30-2RA S13 M30-5RA S14 M30-10RA Figure 3 Variation in Compressive Strength for different mix of M25 and M30 grades at 3 days editor@iaeme.com

8 Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures Figure 4 Variation in Compressive Strength for different mix of M25 and M30 grades at 7 days Figure 5 Variation in Compressive Strength for different mix of M25 and M30 grades at 28 days From results obtained we can conclude that the compressive strength of concrete decreases with increase in the percentage of rubber in the concrete mix for both the grade of concrete. After the addition of 1% superplasticizer a small fraction of strength has increased because of low w/c ratio Results of Flexural Strength Test on beams Results obtained from Flexural Strength tests are tabulated below in Table 8. The graphical form of results is shown in Figure 6. Table 8 Test results of Flexural Strength Test Specimen Batch Title Flexural Strength (N/mm 2 ) 28 Days S1 M25-C 3.60 S2 M25-2R 3.65 S3 M25-5R 3.70 S4 M25-10R 3.78 S5 M25-2RA 3.67 S6 M25-5RA 3.71 S7 M25-10RA 3.82 S8 M30-C 4.40 S9 M30-2R 4.47 S10 M30-5R 4.52 S11 M30-10R 4.56 S12 M30-2RA 4.42 S13 M30-5RA 4.57 S14 M30-10RA editor@iaeme.com

9 Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu Figure 6 Variation in Flexural Strength for different mix of M25 and M30 grades at 28 days Test results reveal that the flexural strength of concrete increases with the increase in the percentage of tyre fibres. Use of high tensile strength material (tyre rubber fibres) in concrete by replacing the low tensile material (rocky aggregates) is the main reason behind the increased flexural strength. Addition of 1% superplasticizer has further increased the flexural strength of concrete. 4. CONCLUSIONS Compressive strength of concrete decreases after the replacement of coarse aggregates with tyre fibres on concrete, but the compressive strength is increased to some extent on addition of admixture to the concrete. For M25 compressive strength is reduced to 9%, 20% and 28% respectively on replacement of 2%, 5% and 10% of coarse aggregates by rubber fiber on concrete. For M25 compressive strength is reduced to 5%, 15% and 24% respectively on replacement of 2%, 5% and 10% of coarse aggregate by rubber fiber and the addition of 1% admixture on concrete. For M30 compressive strength is reduced to 10%, 20% and 24% respectively on replacement of 2%, 5% and 10% coarse aggregate by rubber fiber on concrete. For M30 compressive strength is reduced to 5%, 11% and 17% respectively on replacement of 2%, 5% and 10% coarse aggregate by rubber fiber and the addition of 1% admixture on concrete. According to results of flexural strength of concrete, flexural strength is increased by addition of rubber. Which indicate the fracture resistance of concrete prism is increased by addition of rubber in concrete. Ductility and flexibility of concrete is increased considerably by addition of rubber on the worth of reduced stress capability. Toughness of concrete is improved by addition of tyre rubber fibres. Rubber absorbs strain energy and improved deformability and toughness. In flexural test conventional concrete ruptured quickly, while mixing of rubber in concrete leads to their partial bonding together and it does not completely broken. Rubber mixed concrete used act as a crack resisting material. Bulk density and weight of concrete is decreased while adding rubber in concrete editor@iaeme.com

10 Study of the Behaviour of Concrete after Partial Replacement of Coarse Aggregates by Waste Tyre Rubber Fibres and Addition of Admixtures Addition of superplasticizer has increased workability, compressive strength and flexural strength for all the grades of concrete. Mix prepared with tyre rubber fibres failed to increase the compressive strength of concrete, rather it has reduced it. So this mix should not be used in areas where compressive strength is more important like in structural members etc. Mix prepared though has increased the toughness and flexural strength of concrete. So it can easily be used in areas where flexural strength is more important like in non-load bearing wall member as light weight concrete wall in highway construction, as a better shock absorbing construction material, in runways and taxiways of airport, in earthquake resistant building, for industrial floorings and for better thermal and sound insulation structure etc. REFERENCES [1] Agarwal B.D., Broutman L.J., "Analysis and Performance of Fiber Composites", John Wiley & Sons, New York, [2] Arun Kumar Jain, Ashok Kumar Jain and B.C. Punmia, Reinforced Concrete Structures, Vol. 1, published by Laxmi Publications Pvt. Ltd, [3] Barbosa Antonio F. and Ribeiro Gabriel O., "Analysis of reinforced concrete structures using ANSYS nonlinear concrete model", Computational Mechanics, New Trends and Applications, Barcelona, Spain [4] Biel T.D. and H. Lee, Use of recycled tire rubbers in concrete. In Proceedings of ASCE 3rd Material Engineering Conference Infrastructure: New Materials and Methods of Repair, San Diego, CA, 1994, pp [5] B.N. Dutta and S. Dutta, Estimating and Costing in Civil Engineering, 24th revised edition, published by UBS Publishers Distributors, New Delhi, [6] Eldin N.N. and Senouci A.B., ''Rubber-tyre particles as concrete aggregates'', Journal of Material in Civil Engineering, ASCE, 5(4), 1993, pp [7] Epps J.A., ''Uses of recycled rubber tyre in highways'', Synthesis of highway practice 198, Transportation Research Board, National, [8] Hernandez Oliveres F. and Barluenga G., "Fire performance of recycled rubber-filled high-strength concrete", Cement and Concrete Research, Vol 34, No. 1-3, 2003, pp [9] Ilker Bekir Topcu, The properties of rubberized concrete, Cement and Concrete Research, 1995, Vol. 25, No.2, pp , [10] IS: , Method of Test for Concrete Bureau of Indian Standards, New Delhi [11] IS: , Method of sampling and analysis of Concrete, Bureau of Indian Standards, New Delhi [12] IS: (Part 1), Methods of test of aggregates for concrete, Particles size and shape, Bureau of Indian Standards, New Delhi [13] IS: (Part 3), Methods of test of aggregates for concrete, specific gravity, density, voids, absorptions and buckling, Bureau of Indian Standards, New Delhi [14] IS: , Specification for coarse and fine aggregates from natural sources for concrete, Bureau of Indian Standards, New Delhi [15] IS: , Specification for 53 grade ordinary Portland cement, Bureau of Indian Standards, New Delhi editor@iaeme.com

11 Abhishek Tiwari, Bajrang Lal Panigrahi and Rustam Sahu [16] IS: , Specification for admixtures for concrete, Bureau of Indian Standards, New Delhi [17] IS: , Specification for concrete slump test apparatus, Fourth Reprint November [18] IS: , For Plain and reinforced concrete, forth revision, Bureau of Indian Standards, New Delhi [19] IS: , Recommended guidelines for concrete mix proportioning, Bureau of Indian Standards, New Delhi [20] Lee B.I, Burnett L., Miller T., Postage B., Cuneo J., "Tyre rubber/cement matrix composites", Journal of Material Science Letter, Vol. 12, No. 13, 1993, pp [21] N. Krishna Raju, Prestressed Concrete, published by Tata McGraw-Hill Education, [22] N. Subramanian, Design of Reinforced Concrete Structures, published by Oxford University Press, 16 Jan [23] N.I. Fattuhi and L.A. Clark, Cement-based materials containing shredded scrap tyre rubber, Construction and Building Materials, Vol. 10, No. 4, 1996, pp , [24] Segre N., Joekes N., "Use of tyre rubber particles as addition to cement paste", Cement and Concrete Research, Vol. 30, 2000, pp [25] S.K. Duggal, Building Materials, fourth edition, published by New Age International (P) Limited, [26] Thomas Dyer, Concrete Durability, published by CRC Press, 01 May [27] Topcu I.B., "The properties of rubberized concretes", Cement and Concrete Research, Vol. 25, No. 2, 1995, pp [28] Zaher K.K., Bayomy F.M., "Rubberized Portland Cement Concrete", Journal of Materials in Civil Engineering, Vol. 11, No. 3, 1999, pp