Australian Journal of Basic and Applied Sciences

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1 AENSI Journals Australian Journal of Basic and Applied Sciences ISSN: Journal home page: Influences of Polypropylene Fiber in Modulus of Elasticity, Modulus of Rupture and Compressive Strength of Concrete 1 K.Anbuvelan and 2 Dr.K.Subramanian 1 Research Scholar, Anna University, Chennai , India. 2 Professors & Head, Department of Civil Engineering, Coimbatore Institute of Technology, Coimbatore , India. A R T I C L E I N F O Article history: Received 25 January 2014 Received in revised form 8 April 2014 Accepted 20 April 2014 Available online 10 May 2014 A B S T R A C T This paper presents the relationship between modulus of elasticity and, modulus of rupture relationship with compressive strength of M60 concrete incorporating Polypropylene fiber. Comparing the experimentally obtained results with the mechanical properties calculated using the recommend relationship from the various design codes, one finds substantial variation in the data. A new empirical relationship between elastic modulus, modulus of rupture and compressive strength of Polypropylene fiber based M60 concrete is proposed. Keywords: High performance concrete, Modulus of elasticity, Modulus of rupture, Compressive strength, Polypropylene fiber 2014 AENSI Publisher All rights reserved. To Cite This Article: K. Anbuvelan, Dr. K. Subramanian, Influences of Polypropylene Fiber in Modulus of Elasticity, Modulus of Rupture and Compressive Strength of Concrete. Aust. J. Basic & Appl. Sci., 8(7): , 2014 INTRODUCTION The static modulus of elasticity, modulus of rupture and compressive strength is important properties of concrete. These are the basic parameters for computing deflection in reinforced concrete structures. Various countries have been established their design codes based on this empirical relationship between static modulus of elasticity, modulus of rupture and compressive strength of plain concrete at 28 days of curing. The Indian code of practice (IS 456) recommends the empirical relation between the static modulus of elasticity and cube compressive strength of concrete as, The ACI code (ACI -318) defines the relationship between elastic modulus of concrete and cylinder compressive strength for calculating deflection as, The New Zealand Code (NZS 3101) defines elastic modulus for normal strength concrete as, The Euro-code, recommends the following equation for static modulus of elasticity of concrete from its cube compressive strength of concrete as, The British Code of practice (BS 8110) recommends the following expression for static modulus of elasticity with the cube compressive strength of concrete as, (1) (2) (3) (4) Corresponding Author: K.Anbuvelan, Research Scholar, Anna University, Chennai , India ksanbuvelan@yahoo.co.in

2 226 K.Anbuvelan and Dr.K.Subramanian, 2014 Also, the Indian code of practice (IS: 456) recommends the empirical relation between the static modulus of rupture and cube compressive strength of concrete as, The ACI Code (ACI -318), defines the flexural tensile or modulus of rupture of concrete as, The New Zealand Code (NZS 3101) defines flexural tensile or modulus of rupture for normal strength concrete as, The Euro-code (EC-02) recommends the relationship between flexural tensile or modulus of rupture of concrete and cube compressive strength of concrete as, The Canadian Code of Practice (CSA) defines the flexural tensile or modulus of rupture of concrete from its cylinder compressive strength of concrete as, All the above empirical relationship is only for plain concretes. In the literature, only a few relationships of this kind are available Therefore, these experiments focused on establishing an empirical relationship between static modulus of elasticity and modulus of rupture based on the compressive strength of concrete containing Polypropylene fiber. Research Significance: This paper provides information on the relationship between experimentally obtained modulus of elasticity, modulus of rupture and compressive strength of plain concrete and Polypropylene fiber concrete at 28 days. From the experimental results, the comparison of mechanical properties of concrete is derived from the codes of various countries. An attempt is made to form an empirical relationship between elastic modulus, modulus of rupture using the compressive strength of concrete containing Polypropylene fiber up to 0.2%. Objectives: For localized materials and conditions the effect of Polypropylene fiber on the relationships between static modulus of elasticity, modulus of rupture and compressive strength of concrete has not been clearly established. 1. To study the design codes of various countries for understanding the static modulus of elasticity, modulus of rupture and compressive strength relationships and compared with the relationships to concrete containing Polypropylene fiber. 2. To propose new relationships linking static elastic modulus, modulus of rupture and compressive strength of Polypropylene fiber based concreted based on experimentally obtained results. An experimental program: Material properties: The materials consisted of 53-grade Ordinary Portland Cement, Natural River Sand, Crushed Granite Coarse Aggregate of maximum size 12.5mm, Ordinary portable water for mixing and curing and a Super Plasticizing admixture. Figure 1 shows the experimental setup, Table 1 Shows the properties of Polypropylene fiber, Table 2 Shows the Concrete mix design details and Table 3 Shows the Cube and Cylinder compressive strength test details. (5) (6) (7) (8) (9) (10)

3 227 K.Anbuvelan and Dr.K.Subramanian, 2014 Fig. 1: Shows the experimental setup. Table 1: Properties of Polypropylene fibre. Sl. No. Property Results 1. Absorption Nil 2. Fiber length 12mm 3. Melt point 162 o C 4. Thermal conductivity Low 5. Acid & Salt resistance High 6. Specific gravity Modulus (young's) 0.5 (3.5 KN/mm 2 ) 8. Ignition Point 590 o C 9. Alkali Resistance Alkali Proof 10. Aspect Ratio 80 Table 2: Concrete Mix design details. Grade of concrete Cement Fine aggregate Coarse aggregate W / C M Table 3: Shows the Cube and Cylinder compressive strength test details. Sl. No. Mix Addition of fiber in concrete, % f ck in N/mm 2 f ck in N/mm 2 1 Mix-I Mix-II Mix-III Mix-IV Results And Discussion Static Modulus Of Elasticity: A comparison of static modulus of elasticity obtained experimentally and that obtained from the empirical expressions given by the various design codes for both plain concrete and Polypropylene fiber concrete is presented in Figures 2 & 3. Table 4: Comparison of codal provisions for static modulus of elasticity, Ec in N/mm 2. Sl. No Mixes Measured value, Ec in N/mm 2 As per IS: 456 Code As ACI:318 Code As per New Zealand Code, NZS:3101 As per Euro Code, EC:02 1 Mix-I Mix-II Mix-III Mix-IV As per BS: 8110 Fig. 2: Comparison of codal provisions for static modulus of elasticity.

4 228 K.Anbuvelan and Dr.K.Subramanian, 2014 Fig. 3: Comparison of codal provisions for flexural tensile strength concrete. The figure 2 shows the Modulus Of Elasticity predicted by IS: & EC are higher than comparable to other code prediction. From the figure-2 it is concluded that, the measured value of Modulus Of Elasticity (MOE) for Mix I is equal to BS: 8110 code and it is the low side comparison with other code predictions. Similarly for the Mix-II the experimentally measured values are high in comparison with BS: 8110 code and lower with all other code provisions. For Mix III and Mix IV shows that the measured value of Modulus of Elasticity is low compared to all other code provisions. As the compressive strength of concrete varies, the measured and predicted values of concrete also varying. Based on the regression analysis of the experimentally obtained test results, the proposed correlations of the modulus of elasticity and compressive strength of the cube and cylinder of plain and Polypropylene fiber based concrete are given below: For cube compressive strength, For cylinder compressive strength, Table 5 (a): Constants for empirical relationship between static modulus of elasticity and compressive strength, C1. Sl. No. C1 for cube compressive strength description Mix-I Mix-II Mix-III Mix-IV 1. 1 As per measure value As per IS:456 Code As per ACI:318 Code As per New Zealand Code, NZS: As per Euro Code, EC: As per BS: Table 5 (b): Constants for empirical relationship between static modulus of elasticity and compressive strength, C2. Sl. No. C2 for cylinder compressive strength description Mix-I Mix-II Mix-III Mix-IV 1. 1 As per measure value As per IS:456 Code As per ACI:318 Code As per New Zealand Code, NZS: As per Euro Code, EC: As per BS: Modulus of Rupture: A comparison of static modulus of rupture obtained experimentally and that obtained from the empirical expressions given by the various design codes for both plain concrete and Polypropylene fiber concrete is presented in Table - 6. (11) (12)

5 229 K.Anbuvelan and Dr.K.Subramanian, 2014 Table 6: Comparison of codal provisions for flexural tensile strength concrete, f r in N/mm. 2 Sl. No. Mixes Measured value, f r In N/mm 2 As per IS: 456 Code As ACI:318 Code As per New Zealand Code, NZS: 3101 As per Euro Code, EC:02 As per Canadian Code of Practice (CSA) 1 Mix-I Mix-II Mix-III Mix-IV From the Table- 6, the flexural tensile strength of the experimental values of concrete is on the higher side compared to other code provisions. Table 7a & 7b are showing the details of empirical relationships between flexural tensile strength vs cube compressive strength and flexural tensile strength vs cylindrical compressive strength respectively. The IS code predicted values are high compared to other code provision and the value is low to the experimentally measured values. The values of constant C1 and C2 are high for Mix-II and low for Mix-IV. Based on the regression analysis of the experimentally obtained test results, the proposed correlations between flexural tensile strength and compressive strength of the cube and cylinder of plain and Polypropylene fiber based concrete are given below: For cube compressive strength For cylinder compressive strength Table 7(a): Constants for empirical relationship between static modulus of elasticity and compressive strength, C1 Sl. No. C1 for cube compressive strength description Mix-I Mix-II Mix-III Mix-IV 1. 1 As per measure value As per IS:456 Code As per ACI:318 Code As per New Zealand Code, NZS : As per Euro Code, EC: As per BS : Table 7(b): Constants for empirical relationship between static modulus of elasticity and compressive strength, C2. Sl. No. C2 for cylinder compressive strength description Mix-I Mix-II Mix-III Mix-IV 1. 1 As per measure value As per IS:456 Code As per ACI:318 Code As per New Zealand Code, NZS : As per Euro Code, EC: As per BS : Conclusions: This study of the experimentally obtained elastic modulus, modulus of rupture of plain concrete and steel fiber concrete at 28 days and the corresponding code provisions of select countries, led to the following conclusions: 1. The experimental measured value of the static modulus of elasticity of Polypropylene fiber reinforced concrete is a lower side comparison to IS: Code, ACI: 318 code, EC:02 code, NZS: 3101 code & BS: 8110 code provisions. 2. IS: , EC: 02, ACI: 318 and NZS: 3101 predict higher modulus of elasticity than BS: The experimental flexural tensile strength was higher than the code based flexural tensile strengths for all the mixes and for all, the percentage of addition of Polypropylene fiber in plain concrete. 4. The new empirical relations for elastic modulus, modulus of rupture and compressive strength of concrete containing different dosage of Polypropylene fiber is proposed. ACKNOWLEDGMENT The authors are thankful to the authorities of Coimbatore Institute of Technology for extending their help and the facilities for carrying out the above work in Structural Engineering Laboratory of the Institution. (13) (14)

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