Behaviour of Glass Fibre Reinforced Concrete Using Ultra Fine Micro silica and Copper Slag IJETED

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1 Behaviour of Glass Fibre Reinforced Concrete Using Ultra Fine Micro silica and Copper Slag Ardra. P.T #1, Sharmila. K #2 #1 Student (M.E. Structural Engineering), JCT College of Engineering and Technology, Coimbatore, #2 Assistant Professor, The Department of Civil Engineering, JCT College of Engineering and Technology, Coimbatore, ABSTRACT Concrete is a widely used construction material around the world, and its properties have been undergoing changes through technological advancement. Numerous types of concrete have been developed to enhance the different properties of concrete. The earliest is the traditional normal strength concrete which is composed of only four constituent materials, which are cement, water, fine aggregate and coarse aggregate. With a fast population growth and a higher demand for housing and infrastructure, accompanied by recent developments in civil engineering, higher strength concrete was needed. This thesis work focuses on investigating the characteristics of M30 grade concrete with partial replacement of cement using ultra-fine micro silica and sand by copper slag. Different series of concrete mixtures were prepared for this experimental study. Cement is replaced with ultra-fine micro silica at proportions involving 0%, 5%, 10% and 15% and sand is replaced with copper slag at constant proportion 20%, 40% and 60%. All specimens were cured for 7 days and 28 days to investigate the compressive strength, split tensile strength and flexural strength. It is found that by the partial replacement of cement using ultra fine micro silica and sand by copper slag helped in improving the strength and enhanced mechanical properties of the concrete substantially compared to the normal mix concrete. Key words: Copper Slag, Glass Fibre, Superplasticizer, Ultra Fine Micro Silica, Compressive Strength, Flexural Strength, Split Tensile Strength. INTRODUCTION Concrete is composite material containing hydraulic cement, water, coarse aggregate and fine aggregate. The resulting material is a stone like structure which is formed by the chemical reaction of the cement and water. This stone like material is a brittle material which is strong in compression but very weak in tension. This weakness in the concrete makes it to crack under small loads, at the tensile end. These cracks gradually propagate to the compression end of the member and finally, the member breaks. The formation of cracks in the concrete may also 2016 RS Publication, rspublicationhouse@gmail.com Page 256

2 occur due to the drying shrinkage. These cracks are basically micro cracks. These cracks increase in size and magnitude as the time elapses and the finally makes the concrete to fail. The formation of cracks is the main reason for the failure of the concrete. To increase the tensile strength of concrete many attempts have been made. One of the successful and most commonly used methods is providing steel reinforcement. Steel bars, however, reinforce concrete against local tension only. Cracks in reinforced concrete members extend freely until encountering are bar. Thus need for multidirectional and closely spaced steel reinforcement arises. That cannot be practically possible. Fiber reinforcement gives the solution for this problem. So to increase the tensile strength of concrete a technique of introduction of fibers in concrete is being used. These fibers act as crack arrestors and prevent the propagation of the cracks. These fibers are uniformly distributed and randomly arranged. This concrete is named as fiber reinforced concrete. The main reasons for adding fibers to concrete matrix is to improve the post cracking response of the concrete, i.e., to improve its energy absorption capacity and apparent ductility, and to provide crack resistance and crack control. Also, it helps to maintain structural integrity and cohesiveness in the material. The initial researches combined with the large volume of follow up research have led to the development of a wide variety of material formulations that fit the definition of fiber Reinforced Concrete. MATERIALS 1. Cement Ordinary Portland cement conforming to IS and IS was adopted in this work. The cement used is 53 Grade. Table 1: properties of cement Sl. No Properties Values 1 Consistency test 34 2 Specific gravity Fine Aggregate 3 Initial setting time 30 minutes 4 Fineness test 4.33% Natural sand which is easily available and low in price was used in the work. It has cubical or rounded shape with smooth surface texture. Being cubical, rounded and smooth texture it give good workability. Particles of this sand have smooth texture. Sieve analysis was done to find out fineness modulus and specific gravity for sand as per IS RS Publication, rspublicationhouse@gmail.com Page 257

3 Table 2: Properties of fine aggregates Sl. Properties Values No 1 Specific gravity Fineness modulus Water absorption test 1% 5 Gradation Zone III 3. Coarse Aggregate The aggregate used in this project mainly of basalt rock which comes under normal weight category. The aggregates are locally available. 50% of the aggregate used are of mm size and remaining 50% are of 20mm size. The coarse aggregate was also tested for various properties like specific gravity test, fineness modulus, crushing strength test, water absorption test to check their suitability for the experiment. Table 3: properties of coarse aggregate Sl. No Properties Values 1 Specific gravity Fineness modulus Impact value 8% 4 Water absorption test 0.5% 4. Ultra-Fine Micro Silica Micro silica is one of the artificial pozzolans, commonly used as mineral admixture in FRC. Silica fume is very fine non- crystalline silica, produced in electric arc furnaces, as a byproduct of the production of elemental silicon or alloys containing silicon also known as condensed silica fume or micro silica. It is mainly amorphous silica with high SiO 2 content, extremely small particle size and large surface area, highly reactive pozzolano used to improve mortar and concrete. It improves durability primarily by reducing permeability to water and chlorides. 5. Copper Slag Copper slag is a by-product material produced from the process of manufacturing copper. As the copper settles down in the smelter, it has a higher density, impurities stay in the top layer and then are transported to a water basin with a low temperature for solidification. The end product is a solid, hard material that goes to the crusher for further processing. Copper slag used in this work was bought from Coimbatore RS Publication, rspublicationhouse@gmail.com Page 258

4 Table 4: Physical properties of copper slag Table 5: Chemical properties of copper slag Physical properties Particle shape Appearance Type Copper slag Irregular Black and glassy Air cooled Specific gravity 3.91 Percentage of voids % 35 Bulk density g/cc 2.08 Fineness modulus 3.47 Fineness m 2 /kg (after grinding) 6. Super Plasticizer 125 Sl. NO Chemical Component % of chemical component 1. SiO Fe 2 O Al 2 o Cao Na 2 O K 2 O Mn 2 O TiO SO CuO Sulphide 0.25 Sulphur 12. Insoluble residue Master Glenium 51 is poly carboxylic ether based high range water reducing new second generation super plasticizer concrete admixture. This product has been primarily developed for applications in high performance concrete where the highest durability and performance is require Table 6: Chemical properties of micro silica Table 7: Properties of Glenium 51 Chemical parameter SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Total alkalies (Na 2 O) LOI Ultra fine micro silica (%) Aspect Relative density Test results Light brown liquid 25 o ph > 6 Density kg/litre Specific gravity Water Water quality must be established on the same line as that for using reinforced concrete. The water reacts with the cement, which bonds the other components together, creating a robust stone-like material. Water is then mixed with this dry composite, which produces a semi-liquid 2016 RS Publication, rspublicationhouse@gmail.com Page 259

5 that workers can shape a chemical process called hydration. The cement paste glues the aggregate together, fills voids within it, and makes it flow more freely. CONCRETE MIX DESIGN Cement : kg/m 3 Fine aggregate : kg/m 3 Coarse aggregate : kg/m 3 Water : litre Admixtures : 7.8 kg /m 3 Water-cement ratio : 0.45 TEST RESULTS AND DESCRIPTION The results of the mechanical properties obtained based on the specimens tested as per Indian standard test procedures are discussed. M30grade of concrete, three different percentages of ultrafine micro silica and three percentages of copper slag are replaced by cement and fine aggregate. Compressive Strength: Table: 8 Compressive Strength of Normal Concrete and Glass fiber,ultra fine micro silica & copper slag Added Concrete 7,28 days ( Mean value) S.NO NAME OF THE SPECIMEN PERCENTAGE OF REPLACEMENT COMPRESSIVE STRENGTH (N/mm2) (GF+MS+CS) 7 DAYS 28 DAYS 1 M M M M M M M M M M M M M Figure 3: Graphical representation of M30 compressive strength by replacement of 20% copper 2016 RS Publication, rspublicationhouse@gmail.com Page 260

6 compressive strength N/mm2 International Journal of Emerging Trends in Engineering and Development Issue 6, Vol. 2 (March 2016) Compressive strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (20%) and glass fibre (1%) compressive strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the compressive strength reduces % 5% 10% 15% 20% percentage of micro silica 7 day 28 day Figure 4: Graphical representation of M30 compressive strength by replacement of 40% copper Compressive strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (40%) and glass fibre (1%) compressive strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the compressive strength reduces. Figure5: Graphical representation of M30 compressive strength by replacement of 60% copper Compressive strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (60%) and glass fibre (1%) compressive strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the compressive strength reduces RS Publication, rspublicationhouse@gmail.com Page 261

7 Split tensile strength: Table: 9 Split tensile Strength of Normal Concrete and Glass fiber,ultra fine micro silica & copper slag Added Concrete 7,28 days ( Mean value) S.NO NAME OF THE SPECIMEN PERCENTAGE OF REPLACEMENT (GF+MS+CS) SPLIT TENSILE STRENGTH (N/mm 2 ) 7 DAYS 14 DAYS 1 M M M M M M M M M M M M M Figure 6: Graphical representation of M30 split tensile strength by replacement of 20% copper Split tensile strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (20%) and glass fibre (1%) tensile strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the split tensile strength reduces RS Publication, rspublicationhouse@gmail.com Page 262

8 Figure7: Graphical representation of M30 split tensile strength by replacement of 40% copper Split tensile strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (40%) and glass fibre (1%) tensile strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the split tensile strength reduces. Figure 8 : Graphical representation of M30 split tensile strength by replacement of 60% copper Split tensile strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (40%) and glass fibre (1%) tensile strength increases at 7 day and 28 day with the replacement of micro silica up to 10% and thereafter the split tensile strength reduces. Flexural Strength: Table: 10 Flexural Strength of Normal Concrete and Glass fiber, ultra fine micro silica & copper slag Added Concrete 28 days ( Mean value) S.NO NAME OF THE SPECIMEN PERCENTAGE OF REPLACEMENT (sisal fibre + GGBS) FLEXURAL STRENGTH (N/mm2) 28 DAYS 1 M M M M M M M M M M M RS Publication, rspublicationhouse@gmail.com Page 263

9 12 M M Figure 9: Graphical representation of M30 flexural strength by replacement of 20% copper slag Flexural strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (20%) and glass fibre (1%) tensile strength increases at 28 day with the replacement of micro silica up to 10% and thereafter the flexural strength reduces. Figure 10: Graphical representation of M30 flexural strength by replacement of 40% copper slag Flexural strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (40%) and glass fibre (1%) tensile strength increases at 28 day with the replacement of micro silica up to 10% and thereafter the flexural strength reduces RS Publication, Page 264

10 Figure 11: Graphical representation of M30 flexural strength by replacement of 60% copper slag Flexural strength is plotted against various percentages of micro silica. In the above chart constant percentage of copper slag (60%) and glass fibre (1%) tensile strength increases at 28 day with the replacement of micro silica up to 10% and thereafter the flexural strength reduces. CONCLUSION Copper slag have irregular shapes and more fine particles contributing to improved compressive strength, split tensile strength, flexural strength compared to natural sand concrete. The increase in compressive strength can be contributed due to reduced capillary pore size and usage of micro silica as supplementary cementitious material. The bonding strength also increased due to use of micro silica which in turn enhances strength. Addition of micro silica, copper slag and glass fiber increases the compressive strength by 10.74%, 7%,2.06%,8.435% respectively. Addition of micro silica, copper slag and glass fiber increases the split tensile strength by 0.88%, 0.92%, 1.1%,.65%respectively. Addition of micro silica, copper slag and glass fiber increases the flexural strength by 0.89%, 0.36%, 1.16%,0.85%respectively. It can thus be concluded that glass fiber reinforced concrete with replacement of up to 40% and ultra-fine micro silica up to 10% for M20 possesses excellent compressive strength, tensile strength and flexural strength. The project investigation has bought out behavior of glass fiber reinforced concrete using ultra fine micro silica and copper slag. The test result shows that by the partial replacement of cement using ultra fine micro silica and sand by copper slag helped in improving the strength and enhanced mechanical properties of the concrete substantially compared to the normal mix concrete. REFERENCE [1] IS 456 (2000) Indian standard code of practice for Plain and Reinforced [2] Concrete, Bureau of Indian Standards, New Delhi. [3] IS 5816 (1970), Method of tests for splitting tensile strength of concrete 2016 RS Publication, Page 265

11 [4] Cylinders, Bureau of Indian Standards, New Delhi. [5] IS 8112, Indian standard specification for 43 grade ordinary Portland Cement, [6] Bureau of Indian Standards, New Delhi. [7] IS (1982), Recommended guidelines for Concrete Mix Design, [8] IS 516:1959,Indian standards hand book on concrete mixes [9] IS 12269:1987,Specification for 53 grade ordinary portland cement [10] Muhsin Mohyiddeen et al (2015),Effect of Silica Fume on Concrete Containing Copper Slag as Fine Aggregate [11] Binaya Patnaik et al (2015), strength and durability properties of copper slag admixed concrete [12] Jayapal Naganur and chethan B.A(2014),The effect of using copper slag as a partial replacement of fine aggregate on the properties of cement concrete. [13] Srinivas C.H and S.M Muranal (2014), The study of concrete containing copper slag as fine aggregate. [14] S.Tanveer Hussain et al, (2014), study of strength properties of concrete by using micro silica and nano silica. [15] Umesh sharma et al (2014), Use of Micro-silica as Additive to Concrete-state of Art. [16] S.S.SHEBI et al (2013),Using of Micro silica for Strength Improvement of Fiber Reinforced Cementitious Surface Compounds. [17] Avinash Gornale et al (2012),Strength Aspects of Glass Fibre Reinforced Concrete. [18] Verma Ajay (2012),Effect of Micro Silica on The Strength of Concrete with Ordinary Portland Cement. [19] S.S.Pimplikar et al (2011),Glass Fibre Reinforced Concrete Use in Construction RS Publication, rspublicationhouse@gmail.com Page 266