EXPERIMENTAL STUDY OF POLYPROPYLENE FIBRE INCOPORATED CONCRETE

Transcription

1 EXPERIMENTAL STUDY OF POLYPROPYLENE FIBRE INCOPORATED CONCRETE T.Nanda kumar 1, V.Johnpaul.,M.E 2 and Dr.N.Balasundaram 3 1 PG Student, Department of Civil Engineering, Karpagam University, Coimbatore 2 Assistant Professor, Department of Civil Engineering, Karpagam University, Coimbatore 3 Head of department, Civil Engineering, Karpagam University, Coimbatore Abstract Engineered Cementitious Composites (ECC) is an ultra-ductile fibre reinforced cementitious material that embodies a micromechanics based design concept. Introduction of the concrete and polypropylene fibre and collection of literature review and basic material properties are test. This thesis aims at making ECC with a mix which satisfies the strength characteristics required. Therefore various trial mixes are cast. Polypropylene fibres will be adding in various proportions (1%, 1.% and 2% by weight of cement) the increase compressive strength, Tensile strength, flexural strength for M4grade of concrete addition of Polypropylene fibers to concrete. And Cubes, Cylinders and beams cast and the Compressive Strength, Tensile Strength Flexural Strength are tested. Index Terms Polypropylene fibre, Compressive strength, Tensile strength, Flexural strength I. INTRODUCTION Concrete is found everywhere in the world. Annually, more than one ton per capita of concrete is cast for infrastructure construction worldwide. By many measures, concrete is an excellent construction material. Polypropylene Fiber Reinforced Concrete is an embryonic construction material which can be described as a concrete having high mechanical strength, Stiffness and durability. The tensile ductility and self- controlled tight crack width characteristics to enhancing structural safety under severe loading, and durability under normal service loading. The advantages offered by ECC over conventional concrete become even more compelling. ECC is a field-ready ductile concrete that has the potential to significantly contribute to enhancing infrastructure safety, durability and sustainability. Researchers all over the world are developing high performance concrete by adding various fibers, admixtures in different proportions. Various fibers like glass, carbon, Polypropylene fibers provide improvement in concrete properties like tensile strength, durability, shrinkage, impact, erosion resistance and serviceability of concrete. However, the mechanical properties and functional characteristics of concrete will have to be improved, in some ways drastically, and these improvements are already emerging in limited forms. The raw material of polypropylene is derived from monomeric C 3H 6 which is purely hydrocarbon. Its mode of polymerization, its high molecular weight and the way it is processed into fibres combine to give polypropylene fibres very useful properties as explained below: II. PROJECT WORK A. Materials used and its Properties: 1.Cement 2.Fine Aggregate 3.Coarse Aggregate 4.Polypropylene fibres 2.1. Cement: The cement used was Ordinary Portland cement (OPC) Testing of cement was done as per IS: The various test results conducted on the cement are reported in Table 1 Table No. 1: Physical Properties Physical Properties Value Standard observed in value for OPC investigation Fineness 7% Not Exceed 1 Normal Consistency 28% - Vicat initial setting time(minutes) 112 > 3 Vicat final setting time (minutes) 186 < 6 Specific gravity IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 83

2 2.2. Fine Aggregate: As per IS 272 (part I Sec II): 198 Specific Gravity is defined as the ratio of the weight in air of a given volume of soil solids at a stated temperature to the weight in air of an equal volume of distilled water at that temperature. The sieve analysis is conducted to determine the particle size distribution of the fine aggregates. Table No.2: Physical Properties of Fine aggregates Properties Specific Gravity 2.67 Fineness Modulus 2.48 Surface Texture 2.3 Coarse Aggregate: The coarse aggregate are the blue granite stone of which particles greater than 4.7mm they should be hard, strong, dense, durable and clean. It must be free from vein, adherent coating, alkalis, vegetable matters and other deleterious substances. It should be conical shape. Flaky pieces should be avoided. It should confirm to IS 2386(part-1): These are obtained from nearest quarry (ie Coimbatore) with a fineness modulus of 6.81 Crushed rock Creates much better bond between cement paste and the Aggregates The properties of Coarse aggregate are shown below in Table 3. Table 3 Properties of Coarse Aggregate Property Fine Aggregate Smooth Values Specific gravity 2.76 Fineness Modulus Polypropylene fibres (PP): The fibres used were fine polypropylene monofilaments.the fibres were supplied by Reliance Industry by name RECRON. It is available in 3 different sizes i.e. 6mm,12mm and 24 mm.in the present investigation 12mm fibre length is used Polypropylene fibers are new generation chemical fibers. They are manufactured in large scale and have fourth largest volume in production after polyesters, polyamides and acrylics. About 4 million tonnes of polypropylene fibers are produced in the world in a year. Table No.4: Properties of polypropylene fibre S.No Description Value 1 Specific gravity.91 2 Tensile strength -7 (MPa) 3 Young s Modulus (GN/m 2 ) 4 Elongation at failure 21% 4.. Concrete Mix Proportions For 1 m 3 Concrete: M4 Water Cement Fine Aggregate (L) Kg III. Coarse Aggregate 68.4 Kg Kg EXPERIMENTAL STUDY OF FRESH AND HARDENED STRENGTH PROPERTIES 3.1 Workability of fresh concrete Workability of concrete describes the ease or difficulty with which the concrete is handled, transported and placed between the forms with minimum loss of homogeneity. Workability of concrete mixture is measured by Slump test, Compaction Factor test, Veebee Consistometer test. 3.2 Slump Test Slump test is used to determine the workability of fresh concrete. Slump test as per IS: is followed. The apparatus used for doing slump test are Slump cone and tamping rod. Table : Nominal Slump Value for Different Degrees of Workability Placing Conditions Degree of Workabilit y Slump in mm Shallow Very low - Lightly reinforced Low 2-7 Medium -1 without vibrations High 1-1 IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 84

3 Compressive strength=load/ Area (N/mm 2 ) 3.3 Compaction Factor Test Compacting factor of fresh concrete is done to determine the workability of fresh concrete by compacting factor test as per IS: The apparatus used is Compacting factor apparatus. Table 6: Nominal Compaction Factor for Different Degrees of Workability Placing Conditions Degree of Workability Slump in mm Shallow Very low - Lightly reinforced without vibrations Low 2-7 Medium -1 High Hardened Properties Of Concrete The Hardened properties of concrete test specimens are: a) Cube Compressive Test b) Split Tensile Test c) Flexural Strength Test 3.4 Compressive Strength Test Compression strength is maximum force per unit area, in compression, which a material can withstand before breaking. Test specimen may be either cubes or cylinder. In India the 28 strength of 1x1x1mm cubes is taken as 28 strength of concrete. The strength as obtained from cylinders need to be corrected by applying correction factor to obtain equivalent cube strength. The test specimens are tested in compression testing machine, by applying load gradually till the specimens are crushed. At the age of 7, remove 3specimens for testing from the curing tank and immediately place the specimen in the compression testing machine. Apply load gradually at a rate of 14N/mm 2 /min or 32 KN/min till maximum load is reached at which the specimen fails. Note down the load and type of failure. At the age of 28, test the 3 specimens in the same manner and note the load and types of failure. Find out the strength of concrete for each specimen. Find out the average of 3 results shown in figure 1. Fig 1.Compressive Strength of Concrete Table 7 Compressive test results for ECC specimens. Fibres % 7 N/mm2 28 N/mm2 M4 (conventional) PP 1% PP 1.% M4 PP 1% PP 1.% 32.6 Graph 1.Comression Strength (N/mm 2 ) for 7 and Split Tensile Strength Test The test was conducted as per IS 816:1999. For tensile strength test, cylindrical specimens of dimension 1 mm diameter and 3 mm length were cast. In this test three cylinders were tested IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 8

4 C. Flexural strength test The test was conducted as per IS 816:1999. For Flexural strength test, specimen of 1 mm X 2 mm X 1 mm was casted. A beam specimen is placed in the ultimate testing machine of 2kN capacity for testing. Rollers are placed at a centre to centre distance of the beam specimen. The load is increased until the specimen fails and the maximum load applied to the specimen during the test is recorded. The Flexural strength is calculated by using the formula. σ = P l/ bh 2 Where, Fig 2.Split tensile strength of Concrete Split tensile strength was calculated as follows: Spilt Tensile strength (MPa) = 2P / π DL Where, P = Failure Load (KN) D = Diameter of Specimen (1 mm) L = Length of Specimen (3 mm) Table 8. Test Results of Split Tensile Strength Fibres % 7 N/mm2 28 N/mm2 M4 (conventional) Table 9Flexural test results for ECC specimens. Fibres % 7 N/mm2 28 N/mm2 M (conventional) PP 1% PP 1.% PP 1% PP 1.% M4 PP 1% PP 1.% Graph 3. Flexural Strength ( N/mm 2 ) for 7 and 28 M4 PP 1% PP 1.% Graph 2. Split Tensile Strength (N/mm2) for 7 and 28 Fig 3.Flexural strength of Concrete IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 86

5 MIX Table 1.Experimental Results INITIAL CRACK LOAD (KN) ULTIMATE LOAD (KN) DEFLE CTION (Mm) M PP 1% PP 1.% IV. CONCLUSIONS In summary of the above investigations, the following conclusions are made from the experimental results indicated following: The compressive strength is increases with increase in quantity of polypropylene fibre. Addition of polypropylene fibre increases the workability of concrete. The split tensile strength increasing when comparing to conventional concrete results. Therefore the gives maximum compressive strength, split tensile strength and flexural strength. The compressive strength of the concrete with polypropylene fibre is increasing 17% to the conventional concrete at 7. The compressive strength of the concrete with polypropylene fibre is increasing 22% to the conventional concrete at 28. By using of polypropylene fibre the beams will be cast in different volume i.e. 1%, 1.%, 2% respectively. The flexural strength is increasing when comparing to conventional concrete. [3] Studies on the Properties of Steel and Polypropylene Fibre Reinforced Concrete without any Admixture. [4] effect of random inclusion of bamboo fibers on strength behaviour of flyash treated black cotton soil, antony rachel sneha m. john paul v. international journal of civil engineering and technology (ijciet) 216 [] Mechanical properties of Polypropylene Fibrereinforced concrete for M 2 & M 3 mixes: A Comparative study [6] Uniaxial Compressive Strength of Polypropylene Fibre Reinforced Sandcrete Cubes [7] Investigation on Compressive and Tensile Behavior of Fibrillated Polypropylene Fibers Reinforced Concrete [8] IS for concrete design mix. [9] Effect of Copper Slag on Strength of Polypropylene Fiber Reinforced Concrete [1] Effect of Polypropylene Fibres on Flexural Strength of M3 Grade Concrete [11] Experimental Investigation on Polypropylene Fiber Reinforced Concrete With Artificial A.P. Sathe Victor C. Li (213) REFERENCES [1] Polypropylene Fiber Reinforced Concrete-A Review Dr.T.Ch.Madhav,Ramapuram. Victor C. Li (214) [2] Performance of Polypropylene Fibre Reinforced Concrete V. Mohod Victor C. Li (21) IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 87