ADVANCES in NATURAL and APPLIED SCIENCES

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1 ADVANCES in NATURAL and APPLIED SCIENCES ISSN: Published BY AENSI Publication EISSN: January 10(1): pages Open Access Journal Mechanical Properties of High Strength Concrete with Artificial and Natural Fibres Arul Gnanapragasam A. and Praveen Jesuraj V. Assistant Professor, Department of Civil Engineering, SSM Institute of Engineering and Technology, Dindigul Received 12 January 2016; Accepted 28 February 2016; Available 4 April 2016 Address For Correspondence: Arul Gnanapragasam A., Assistant Professor, Department of Civil Engineering, SSM Institute of Engineering and Technology, Dindigul Copyright 2016 by authors and American-Eurasian Network for Scientific Information (AENSI Publication). This work is licensed under the Creative Commons Attribution International License (CC BY). ABSTRACT This paper in essence presents comparative experimental data on the mechanical properties of Polypropylene and coir fibrereinforced concrete under compression, split tensile and flexure. Polypropylene and coir fibre, both with the same concrete design mix M25, have been used to make cube specimens for a compression test, cylinders for a tensile split test and beam specimens for a flexural test. The total dosage of fibres was maintained at 0.15%,0.25%,0.35%,0.45% by volume fraction. The experimental data demonstrated Polypropylene and coir fibres reinforced concrete to be stronger in compression, tensile and flexure at early stages, whilst both fibre reinforced concrete types displayed comparatively the same performance in compression, tensile splitting and flexural strength for 7, 14 and 28 days. KEYWORDS: Polypropylene fibre, Coir fibre, Fibre Reinforced Concrete, Mechanical Properties; INTRODUCTION Concrete made from Portland cement, is relatively strong in compression but weak in tension and tends to be brittle.the weakness in tension can be overcome by the use of conventional steel bars reinforcement and to some extent by the mixing of a sufficient volume of certain fibers. The use of fibers also recalibrates the behavior of the fiber-matrix composite after it has cracked through improving its toughness. The plain concrete fails suddenly when the deflection corresponding to the ultimate flexural strength is exceeded, on the other hand fiber reinforced concrete continue to sustain considerable loads even at deflections considerably in excess of the fracture deflection of the plain concrete. Fiber reinforced concrete has become viable new material used in various constructions such as buildings, pavements, large industrial floors and runways [1]. The first use of fibers in reinforced concrete has been dated to 1870 s. Since then, researchers around the world have been interested in improving the tensile properties of concrete by adding, iron and other wastes. Local interest has been demonstrated through research work performed. In addition to industrial fibers, natural organic and mineral fibers have been also investigated in reinforced concrete [2]. It must be well noted however that the benefits of adding fibres to concrete in construction, which is principally to improve on the residual load-bearing capacity, is influenced by the content, orientation and type of fibres in use. The world has a witnessed rapid increase in the use of fibre reinforced polymer (FRP) materials as a substitute for conventional steel bars in some concrete structures, due to the numerous benefits: high strength, improved toughness, resistance to postcrack propagation and light weight amongst others [3]. Hybrid fibre reinforced concrete (H y FRC) is the use of two or more types of fibres in a suitable combination may potentially improve overall properties of concrete and also result in performance of concrete [12]. Hybrid fibre reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibres of different geometries can act as bridging mechanism over cracks of widths[11]. Recently, many researchers have an orientation to discuss the mechanical properties of the hybrid fibres-reinforced concrete, such as a proper proportion between carbon fibres and To Cite This Article: Arul Gnanapragasam A. and Praveen Jesuraj V., Mechanical Properties of High Strength Concrete with Artificial and Natural Fibres, Advances in Natural and Applied Sciences. 10(1); Pages:

2 49 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: polypropylene fibres, glass fibres and polypropylene fibres, or carbon fibres and glass fibres to concrete. The addition of steel fibres significantly improves many of the engineering properties of mortar and concrete, notably impact strength and toughness [10]. As a result from the previous study this ventures focusing the combination of Polypropylene and coir fibres. The total dosage of fibres was maintained at 0.15%,0.25%,0.35%,0.45% by volume fraction. The M40 grade of concrete was designed by using the codal provisions of IS [9]. Table 1: volume fraction used. Sl.no Combination Volume fraction 1 Coir fibre (FRC 1) 0.15% 0.25% 0.35% 0.45% 2 Polypropylene fibre (FRC 2) 0.15% 0.25% 0.35% 0.45% Half of coir fibre Hybrid fibre % Half of polypropylene fibre Half of coir fibre Hybrid fibre % Half of polypropylene fibre Half of coir fibre Hybrid fibre % Half of polypropylene fibre Half of coir fibre Hybrid fibre % Half of polypropylene fibre Material and Methodology: A. Materials Used: Cement: The Portland Pozzolona Cement of 53 Grade conforming to IS 1489 (Part 1:1991)[8] was used in this study. The specific gravity, initial and final setting of PPC 53 Grade were 3.15, 30 and 600 minutes respectively. Fine Aggregate: Locally available river sand conforming to grading zone II of IS [4]. Sand passing through IS 4.75mm Sieve will be used with the specific gravity of Coarse Aggregate: Locally available blue metal was used. Crushed granite stones of size passing through 20 mm sieve and retained on 10 mm sieve as per IS: [4] was used for experimental purpose. Water: Ordinary portable water without acidity and alkanet available in pump as per IS: [5]. Polypropylene fibre: Polypropylene (PP), also known as Polypropylene, is a thermoplastic polymer used in a wide variety of applications including packaging and labeling, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. Polypropylene fibre Concrete is versatile and can be used in most applications. Polypropylene fibers added to the concrete for strengthening concrete and for protection of concrete against micro cracks. The function of the polypropylene fiber mixed into concrete is not to replace the steel but to avoid the creation of micro cracks in the concrete. Properties of polypropylene fibre: Table 2: properties of polypropylene fibre. property polypropylene Length 20mm Diameter 100µm Specific gravity 0.9 Tensile strength 450MPa Coir Fibre: Coir is a natural fibre extracted from the husk of coconut. Coir is an inexpensive fibre among the natural fibres available in the world. Furthermore, it possesses the advantages of lignocelluloses fibre. In the present study brown coir fibre is used.

3 50 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Fig.1: polypropylene fibre. Fig. 2: Coir fibre. Properties of coir fibre: Table 3: Properties of coir fibre. Property coir Length 100mm Diameter 200µm Specific gravity Tensile strength MPa B. Mix Proportion: The control specimens were made to achieve the target mean strength of 25 MPa in 28 days curing. The detailed mixture proportions for the study are presented in Table 3, while the volume fractions of various fibres used in the mixtures are given in Table 3. Table 3: Detail Mix Proportions. CEMENT F.A C.A 479 kg/m kg/m kg/m C. Casting: In the production of concrete, the constituent materials were initially mixed without fibres. The fibres were then added in small amounts to avoid fibres balling and to produce the concrete with uniform material consistency and good workability [13]. The fine aggregate, coarse aggregate and binder was added in pan and make a proper mix for 3 minutes. The super plasticizer was then mixed thoroughly with the mixing water and added to the mixer. Fibres were dispersed by hand in the mixture to achieve a uniform distribution throughout the concrete, which was mixed for a total of 4 minutes. Mechanical Properties: A.Fresh Concrete Slump Cone Test: The slump test was performed as per IS [7], the slump test is the most well-known and widely used test to characterize the workability of fresh concrete. The inexpensive test, which measures consistency, is used on job sites to determine rapidly whether a concrete batch should be accepted or rejected. B. Hardened Concrete: Compressive Strength Test: For compressive strength test, cube specimens of dimensions 150 x 150 x 150 mm per IS 516:1999 [6] were casted for M40 grade of concrete. The moulds were filled with hybrid fibre concrete and fibre reinforced concrete. After 24 hours the specimens were demoulded and were transferred to curing tank wherein they were allowed to cure for 28 days. These specimens were tested in compression testing machine. In each category, three cubes were tested and their average value is reported by using following formulae.

4 51 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Compressive strength = Load / Area (MPa) Tensile Strength Test: For tensile strength test, cylinder specimens of dimension 150 mm diameter and 300 mm length per IS 516:1999[6] were cast. The specimens were demoulded after 24 hours of casting and were transferred to curing tank wherein they were allowed to cure for 28 days. For the control mix and Hybrid fibre concrete. Split Tensile Strength = 2 P π LD Fig. 3: Testing of Cubes. Fig. 4: Testing of Cylinders. Flexural Test: For flexural strength test, prism specimens of dimensions 700 x 150 x 150 mm were cast. The specimens were demoulded after 24 hours of casting and were transferred to curing tank wherein they were allowed to cure for 28 days. For the control mix and Hybrid fibre concrete. If a > 13.3 cm then, P x l b x d 3P x a b x d Modulus of rupture f b = 2 If a < 13.3 cm, f b = 2 RESULTS AND DISCUSSION A.Fresh Concrete: For the various mix proportions the concrete was tested in slump. The workability of concrete while adding fibres that can improve in average ratio but by adding of hybrid fibres not may not give a great variation than the FRC was resulted below.

5 52 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Table 4: slump cone test. Sl. No Fibre combination Slump value (mm) 1 Nominal coir fibre (FRC 1) 96 3 polypropylene fibre (FRC 2) Hybrid fibre Hybrid fibre Hybrid fibre Hybrid fibre Fig. 5: Graph for slump Cone Test. B.Hardened concrete Test: Table 5: Hardened concrete test for nominal mix. Sl Sam Comp Split tensile Flexural Specimen Curing Days No ples ressive Strength Strength Strength Nominal Nominal Nominal Table 6: Compressive test results for FRC 1. No. Of Days Sl No Specimen Curing Compressive Strength Sample 1 Sample 2 Sample Volume Fraction 1 FRC FRC FRC Fig. 6: Graph for compressive strength of coir (28 days).

6 53 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Table 7: Compressive strength results for FRC 2. Speci No. Of Sl No men Days Curing Compressive Strength sample 1 Sample 2 sample Volume Fraction 1 FRC FRC FRC Fig. 7: Graph for compressive strength of PP(28 days). Table 8: Compressive strength result for HFRC. l. no Specimen No. of days curing Compressive strength Sample 1 Sample 2 Sample 3 HFRC (VF=0.15%) HFRC (VF=0.25%) HFRC (VF=0.35%) HFRC (VF=0.45%) Table 09: Split tensile test result for FRC 1. Sl No. Spec Vol Split tensile strength No. Of Days Curing imen ume Fraction Sample 1 Sample 2 Sample FRC FRC FRC

7 54 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Fig. 8: Graph for compressive strength of HF(28 days). Fig. 9: Graph for split Tensile Strength of Coir (28 days). Fig. 10: Graph for split Tensile Strength of PP(28 days). Table 10: Split tensile test for FRC,HFRC. Sl No. Spec imen No. Of Days Curing Volu me Fraction Split tensile Strength sample 1 sample 2 sample FRC FRC FRC Fig. 11: Graph for split Tensile Strength of HF(28 days).

8 55 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: Fig. 12: Flexural Strength of HFRC. Table 11: Split tensile test for FRC,HFRC. Sl. no Spe Split tensile strength No. of days curing cimen Sample 1 Sample 2 Sample 3 HFRC (VF=0.15%) HFRC (VF=0.25%) HFRC (VF=0.35%) HFRC (VF=0.45%) Table 12: Flexural Strength test. S.no. Specimens No.of days curing Flexural Strength 1 Nominal HFRC HFRC HFRC HFRC Conclusion: The test results showing that at low fibre volume fraction, it is possible to obtain material with enhanced strength and improved toughness from hybrid fibres. The better workability of fresh concrete was obtained in the combination of Polypropylene and coir. 1. The compressive strength of FRC1 concrete was increased 26.22% when compared to control specimens 2. The compressive strength of FRC2 concrete was increased 16.9 % when compared to control specimens 3. The compressive strength of HFRC concrete was increased % when compared to control specimens 4. The tensile strength of FRC1 concrete was increased 36 % when compared to control specimens 5. The tensile strength of FRC2 concrete was increased % when compared to control specimens 6. The tensile strength of HFRC concrete was increased % when compared to control specimens 7. The flexural strength of HFRC concrete was increased 92% when compared to control specimen REFERENCES 1. Padmanaban Iyer, Sara Y. Kenno and Sreekanta, Mechanical Properties of Fibre Reinforced concrete made with Basalt Filament fibre, Journal of Materials in Civil Engineering, Amit Rai, Dr. Y.P Joshi, Applications and Properties of Fibre Reinforced Concrete, 04: Amir, M., Alani, Morteza Aboutalebi, Mechanical Properties of Fibre Reinforced Concrete - A Comparative Experimental Study International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering, 07: IS Specification for Coarse and fine aggregates from Natural sources for concrete, Bureau of Indian Standards. 5. IS "Plain and Reinforced Concrete-Code of Practice", Bureau of Indian Standards,(BIS 2000). Fifth Reprint. 6. IS 516, "Methods of tests for strength of concrete", Bureau of Indian Standards.

9 56 Arul Gnanapragasam A., Praveen Jesuraj V., 2016/ Advances in Natural and Applied Sciences. 10(1) January 2016, Pages: 7. IS 1199, Methods of Sampling and Analysis of Concrete Bureau of Indian Standards. 8. IS 1489 (Part-1), Portland Pozzolana Cement-Specification, Bureau of Indian Standards. 9. IS , "Concrete Mix Proportioning-Guidelines", Bureau of Indian Standards,(BIS 2009), First Revision. 10. Mazin Burhan Adeen, Dr.Alya'a Abbas Al-Attar and Mr.Sa'ad Mahmoud Ra'ouf, Determination of mechanical properties of hybrid steel-nylon fiber reinforced concrete Canadian Center Of Science And Education, 4: Sivakumar, A. and Manu Santhanam, Mechanical properties of high strength concrete reinforced with metallic and non-metallic fibres Cement & Concrete Composites, Elsevier Journals Ltd., 29: Vikrant, S., Vairagade and Kavita S. Kene, Experimental Investigation on Hybrid Fiber Reinforced Concrete International Journal of Engineering Research and Applications, 02: Song, P.S. and S. Hwang, Mechanical properties of high-strength steel fiber-reinforced concrete Construction and Building Materials, Elsevier Journals Ltd., 18: