Concrete mix design using copper slag as fine aggregate

1. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 INTERNATIONAL JOURNAL OF CIVIL ENGINEERING 17 – 19, July 2014, Mysore, Karnataka, India AND TECHNOLOGY (IJCIET) ISSN 0976 – 6308 (Print) ISSN 0976 – 6316(Online) Volume 5, Issue 9, September (2014), pp. 90-99 © IAEME: www.iaeme.com/Ijciet.asp Journal Impact Factor (2014): 7.9290 (Calculated by GISI) www.jifactor.com 90 IJCIET ©IAEME CONCRETE MIX DESIGN USING COPPER SLAG AS FINE AGGREGATE M. C. Nataraja1, G. N. Chandan2, T. J. Rajeeth2 1Professor, Department of Civil Engineering, 2M.Tech. students, Department of Civil Engineering, Sri Jayachamarajendra College of Engineering, Mysore – 570 006, India ABSTRACT This paper presents the experimental results of an on-going project to produce concrete with copper slag as a fine aggregate. Sustainability and resource efficiency are becoming increasing important issues. Here the potential use of granulated copper slag, a relatively heavy material, as a replacement to sand in concrete mixes is explored. The effect of replacing fine aggregate by copper slag on the compressive strength, flexural strength and split tensile strength of concrete are studied in this work. The proposed mix design method was found to be satisfactory for producing concrete with fine aggregates having contrasting properties. Keywords: Compressive strength, Copper slag, Flexural strength, Heavy material, Mix design. 1. INTRODUCTION River sand is being used as fine aggregate in concrete for centuries. However, river sand is not a renewable natural resource. In some regions, river sand has been excessively exploited, which has endangered the stability of river banks and the safety of bridges, and creates environmental problems. On the other hand, river sand is expensive due to excessive cost of transportation from natural sources. Seeking for river sand alternatives has become urgent. Manufactured sand is produced by crushing rock depositions which is generally more angular and has rougher surface texture than river sand particles [6]. The shape and texture of crushed sand particles could lead to improvements in the strength of concrete due to better interlocking between particles. Water reducers and mineral admixtures can be used to improve workability [6]. Few investigations have studied the durability properties and performance characteristics of concrete with copper slag as fine aggregate [3-5]. They have concluded that the copper slag performs similar or better compared to natural sand concrete. Previous researches have shown that good quality concrete can be made using manufactured sand with high amount of microfines. Generally the compressive strength, flexural

2. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India strength, bond strength, water permeability, impact resistance, sulfate resistance and abrasion resistance tend to increase to a certain limit within creasing proportions of microfines. After the limit is reached, the strength decreases because there is not enough paste to coat the aggregate [6]. Since the beginning of the industrial era, slags, the glassy materials left over when metals are pyrometallurgically extracted from ores, have been considered waste. One such material is copper slag which is produced during matte smelting and converting steps of pyrometallurgical production of copper. During matte smelting two separate liquid phases, copper-rich matte (sulphides) and slag (oxides) are formed. It has been estimated that for every ton of copper production about 2.2 tons of slag is generated and in each year, approximately 24.6 million tons of slag is generated from world copper production. Dumping or disposal of this slag causes wastage of metal values and leads to environmental problems. Rather than disposing, these slags can be used taking full advantage of its physico-mechanical properties. The major slag[1] producing regions with quantities is given in Table 1. Slag containing 0.8% copper are either discarded as waste or sold as products with properties similar to those of natural basalt (crystalline) or obsidian(amorphous). Utilisation and recovery of metal depend on the type of slag. Current options of management of this slag are recycling, recovering of metal, production of value added products and disposal in slag dumps or stockpiles. Processed air-cooled and granulated copper slag has number of favourable mechanical properties for aggregate use, including excellent soundness characteristics, good abrasion resistance and good stability. Since copper slag has a low content of CaO, granulated copper slag exhibits pozzolanic properties (Deja and Malolepszy, 1989; Douglas and Mainwaring, 1985). 91 Table 1. Copper slag generation in various regions Regions Copper slag generation/annum in million ton Asia 7.26 North America 5.90 Europe 5.56 South America 4.18 Africa 1.23 Oceania 0.45 2. MIX DESIGN 2.1 Case Study According to the studies by Brindha and Nagan (2011) the mix proportion considered is 1:1.66:3.76 with w/c = 0.45 and 0 to 60% (CC, S20, S40 and S60) of natural sand was replaced by copper slag by weight. The four concrete mixtures with different proportion of copper slag are as shown in Table 2.

3. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India S20 Kg/m3 Cement 340 340 340 340 Copper slag (CS) 0 113.4 226.8 340.2 Water 153 153 153 153 Fine aggregate(NS) 567 453.6 340.2 226.8 Coarse aggregate 1278 1278 1278 1278 Total yield (Kg/m3) 2338 2338 2338 2338 92 Table 2: Concrete mixtures with different proportion of copper slag Mix materials CC Kg/m3 S40 Kg/m3 S60 Kg/m3 In the above mix design, the total yield is less than one cubic meter as shown bellow For control mixture CC (100% natural sand) 3 1m 1 + + + + = 3 10 Air x CA G FA G C G W G W C FA CA By substituting values of mix materials and corresponding specific gravities for control mixture 3 1m 1 3 10 Air x 1278 2.6 567 2.57 340 3.15 153 1 = + + + + 1 [ 3 973.10 + Air ] x = 1m 3 10 1 [ 3 973.10 + 30 ] x = 1m 3 10 By assuming around 3% of air voids, we will get 1m3 of concrete. For control mixture S60 (60% copper slag) 3 1m 1 + + + + + = 3 10 Air x CA G FA G FA G C G W G W C FA FA CA By substituting values of mix materials and respective specific gravities for (S60) 3 1m 1 3 10 Air x 1278 2.6 226.8 2.57 340.3 3.91 340 3.15 153 1 = + + + + + 1 [ 3 927.73 + Air ] x = 1m 3 10 By assuming around 3% of air voids, we will get 1m3 of concrete. [ ] 1 3 927.73 + 30 x = 0.95 ¹ 1m 3 10 Therefore we can conclude that equivalent weight replacement of materials results in less yield.

4. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India 2515 - 2338

5. Percentage decrease in yield x100 7.57% Cement 340 340 340 340 Copper slag (CS) 0 172.36 344.74 517.1 Water 153 153 153 153 Fine aggregate(NS) 567 453.6 340.2 226.8 Coarse aggregate 1278 1278 1278 1278 Total yield (Kg/m3) 2338 2397 2456 2515 93 2338 = Hence we have to go by equivalent volume replacement by considering specific gravity. Modified control mixture – S60 (60% copper slag) 3 1m 1

6. g + + + + + = 3 10 Air x CA G a FA G X FA G C G W G W C FA FA CA

7. g b By substituting values of mix materials and respective specific gravities for (S60) 3 1m 1 3 10 Air x 1278 2.6 226.8 2.57 340.3 3.91 X 2 .57 3.91 340 3.15 153 1

8. = + + + + +

9. 1 [ 3 973.13 + Air ] x = 1m 3 10 By assuming around 3% of air voids, we will get 1m3 of concrete. [ ] 1 3 973.09 + 30 x = 1m 3 10 Therefore by multiplying the specific gravity ratio to the fine aggregate proportion we will end up with equal volume of concrete as that of control mix when copper slag used as natural sand. Therefore modified mix proportion = 1: 2.52: 3.76 with w/c = 0.45 and Modified concrete mixtures with different proportion of copper slag as shown in Table 3. Table 3: Modified concrete mixtures with different proportion of copper slag Mix materials 3. EXPERIMENTAL STUDIES 3.1 Material CC Kg/m3 S20 Kg/m3 S40 Kg/m3 S60 Kg/m3 Ordinary Portland cement of 43 grade conforming to IS: 8112 (1989) [8] with a 28-day compressive strength of 56 N/mm2 is used. Copper slag obtained from Sterlite Industries India Limited (SIIL), Tuticorin, and Tamil Nadu is used. Its specific gravity is 3.91. The fine aggregates used for this work are Natural River sand and copper slag. The physical properties of fine aggregates such as sieve analysis, specific gravity, bulk density, percentage voids etc., were determined as per

10. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India IS: 2386 (1963) [9] and angle of internal friction is determined as per IS 2720 (1986) [10] as shown in Table 4. Chemical composition of copper slag and ordinary Portland cement (OPC) as shown in Table 5. Potable fresh water which is free from organic substances is used for mixing and curing of specimens. Physical properties Natural sand Copper slag Particle shape Irregular Irregular Appearance Brownish Specific gravity 2.61 3.91 Loose State 39 42 Compact state 34 37 Loose State 1.45 1.84 Compact state 1.65 2.15 Fineness modulus 3.14 3.17 Angle of internal friction 45° 49.38° Water absorption, % 1.3 0.3 Moisture content, % 0.43 0.095 Chemical components by mass percentage OPC Al2O3 0.47 2.52 SiO2 1.91 31.92 SO3 6.50 1.34 CaO 91.12 1.25 Na2O - 1.40 MgO - 1.65 K2O - 0.81 Fe2O3 - 59.11 94 Table 4: Physical Properties of Natural Sand and Copper Slag yellow Black and glassy Percentage voids, % Bulk density g/cc Table 5: Chemical composition of copper slag and ordinary Portland cement (OPC) 3.2 Sample preparation Materials Copper slag Cement mortar samples were compacted in three layers using a vibrating table. After 24 h, specimens were removed from the moulds and cured in a water tank for later testing at 3, 7, 28, 56 and 90 days. Concrete specimens were prepared and compacted. The required amounts of coarse

11. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India aggregate, fine aggregate, cement, water, and copper were weighed in separate buckets. The materials were mixed in accordance with IS 10262:2009[11]. The slump of the fresh concrete was determined to ensure that it would be within the designed value. 4. USE OF COPPER SLAG IN OTHER AREAS 95 4.1 Abrasive tools Utilization of granulated copper slag as a ceramic raw material, especially its use as a component in ceramic binders was investigated by Herman (1989). It was found that the introduction of copper slag instead of frit into the binder led to an improvement of mechanical service properties of ceramic abrasive tools [1]. Copper slag was characterised by Szyrle and Wozniak (1988) to find its use in abrasive blasting treatment or in the manufacture of abrasive tools. 4.2 Pavement The use of copper slag aggregates in hot mix asphalt pavements was investigated by Transportation Research Board, Washington (Collins and Cielieski, 1994). Fine copper slag has reportedly been used in hot mix asphalt pavements in California and granulated copper slag has been incorporated into asphalt mixes in Georgia to improve stability. Although it is rarely used, Michigan Department of Transportation Specifications consider reverberatory copper slag to be a conventional coarse and fine aggregate for hot mix asphalt pavement [1]. 4.3 Cutting tools, tiles and glass Use of copper slag as filler instead of conventional lithophone filler was investigated (Szyrle et al., 1988). To improve the properties of grinding and cutting wheels, copper slag filler (0.043 kg of particle size B150 mm) was added to a mixture of an abrasive powder (0.868 kg), powder novolak resin (0.147 kg), a liquid phenol formaldehyde resin (0.037 kg) and iron red pigment (0.013 kg) and this was compacted and hardened for 16 h at B /180 8C. The resulting wheel was used for cutting a steel rod of 60 mm diameter at 3800 rpm. Cutting property of the wheel was superior to the wheel made of conventional lithophone filler. Use of copper slag in the production of tiles was reported by Yasuo (1992). Pictorial representation of copper slag uses in other areas as shown in Fig 1. Fig 1: Pictorial representation of copper slag uses in other areas

12. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India Test type Test name Test standard Slump test IS: 7320 : 1974 Compaction factor test Static test Compression strength test Flexure strength test IS: 9399 [1979] Tensile splitting strength test 96 Fig 2: Compression test Table 6: Experimental programme Fresh concrete Mechanical properties 5. TESTING PROCEDURE IS: 5515 : 1983 IS: 516-1959 IS: 5816 [1999] Table 6 outlines the experimental programme of this study. Tests were carried out on fresh and hardened concrete specimens to evaluate their mechanical properties, concrete design mix proportions and compressive strength results are given in Tables 7 and 8 respectively. Table 7: Mix proportion used in the study Ingredients 0%CS (kg/m3) 100%CS (EW) (kg/m3) 100%CS (EV) (kg/m3) OPC 43 grade 351.33 351.33 351.33 Coarse aggregate 1206 1206 1206 Natural sand 706 0 0 Copper slag 0 706 1057.53 Water 158.1 158.1 158.1 w/c ratio 0.5 0.5 0.5

13. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India 7- days compressive strength (MPa) Natural Sand 35.06 40.07 Copper Slag 36.00 41.57 37.26 44.05 97 Table 8: Compressive strength at 7 and 28 Days for w/c =0.5 Type of sand 28- days compressive strength (MPa) (equivalent volume) Copper Slag (equivalent weight) Fig 3: NS and CS passing through 4.75mm and retained on 2.36mm sieves 6. TEST RESULTS AND DISCUSSION The effect of replacing fine aggregate (NS) by copper slag on the compressive strength, flexural strength and split tensile strength are attempted in this work. However, only compressive strength at 7 and 28 days is presented in Table 8. The surface characteristics of CS and NS can be seen in the photo image taken from 20 pixel camera as shown in Fig 3. From the Table 8 it can be see that in any combination of the aggregate is definitely able to give up the same required strength and the workability is also not a problem, but in case of copper (CS) slag when CS is replaced with equivalent weight because of the availability of more mortar surrounding the aggregate and as result the workability increased in terms of slump. However the compaction factor is more or less same comparable to that of the natural sand. The results of slump and compaction factor are given in Table 9 and the variation of slump as shown in Fig 5. From Table 9 it is clear that the workability for given water is more or less same and hence the sensitivity of the workability behaviour is not critical. Schematic representation of the mix design as shown in Fig 4. Table 9: Slump and Compaction factor results Type of sand Slump, in mm Compaction factor NS 115 0.966 CSEW 140 0.958 CSEV 120 0.978

14. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India Variation of slump for NS and CS 98 Fig 4: Schematic representation of the mix design 115 120 140 140 120 100 80 60 40 20 0 CSV CSW Slump in mm NS Fig 5: Variation of slump The properties of cement-OPC 43 are determined as per IS: 4031-1988 and as shown in Table 10. Table 10. Properties of cement-OPC 43 grade Sl. No. Properties Test Results IS: 8112-1989 Requirements 1 Standard Consistency, % 31.50 No standard value 2 Initial setting time, minutes 125 30 (minimum) 3 Final setting time, minutes 275 600 (maximum) 4 Specific gravity 3.15 No standard value Soundness, 5 Lechatelier’s value, mm 1 10 6 Compressive Strength, MPa 3 Days 32.57 23 (minimum) 7 Days 42.20 33 (minimum) 28 Days 53.67 43 (minimum) Natural sand Copper Slag Copper Slag Deficiency (reduction in Yield)

15. Proceedings of the 2nd International Conference on Current Trends in Engineering and Management ICCTEM -2014 17 – 19, July 2014, Mysore, Karnataka, India From the above studies following conclusion can be drawn, 99 7. CONCLUSIONS Copper slag can be used as an alternative to natural sand in concrete. When copper slag(CS) is replaced with equivalent weight because of the fact more mortar is there to surround the aggregate therefore may workability will increase in terms of slump, however the compaction factor is more or less same comparable to that of the natural sand. Compared to the control mix, there was a slight increase in the strength is due to copper slag. When there is the significant difference in the specific gravity, it is advisable to go by equivalent volume replacement by taking the specific gravity in to account rather than by weight replacement and for lower percentage of replacement of copper slag equivalent weight replacement may also be used with better performance though the yield of the material decreases substantially. Proper mix design taking specific gravity of sand is the criteria to ensure certain performance requirements satisfying the yield. 8. REFERENCES 1. Gorai P, Jana R.K., and Premchand, “Characteristics and utilisation of copper slag – a review”, Resources, Conservation and Recycling 2003, Vol. 39, pp. 299–313. 2. Brindha D and Nagan S, “Durability studies on copper slag admixed concrete“, Asian journal of civil engineering (building and housing), Vol.12, No.5, 2011, pp. 563-578. 3. Khalifa S. Al-Jabri , Abdullah H, Al-Saidy, and Ramzi Taha, “Effect of Copper Slag as a Fine Aggregate on the Properties of Cement Mortars and Concrete”, Construction and Building Materials,Vol. 25, 2011, pp. 933–938. 4. Khalifa S. Al-Jabri, Makoto Hisada, Abdullah H. Al-Saidy, and S.K. Al-Oraimi, “Performance of high strength concrete made with copper slag as a fine aggregate”. Construction and Building Materials, 2009, Vol. 23, pp. 2132–2140. 5. Khalifa S. Al-Jabri, Makoto Hisada, Salem K. Al-Oraimi, Abdullah H. Al-Saidy, “Copper slag as sand replacement for high performance concrete”, Cement and Concrete Composites, 2009, No. 7, Vol.31, pp. 483–488. 6. Li B.X, Ke GJ, Zhou M.K, “Influence of manufactured sand characteristics on strength and abrasion resistance of pavement cement concrete”, Construction and Building Materials, 2011, Vol. 25, No.10, pp. 3849–53. 7. IS: 5515-1983, Specification for compaction factor apparatus, Bureau of Indian Standards, New Delhi. 8. IS: 8112-1989, Specification for 43 grade ordinary Portland cement, Bureau of Indian Standards, New Delhi. 9. IS: 2386-1963, Methods of Test for Aggregates for Concrete, Bureau of Indian Standards, New Delhi. 10. IS: 2720: Part 13 -1986, Methods of Test for Soils - Direct Shear Test, Bureau of Indian Standards, New Delhi. 11. IS: 10262-2009, Proportioning of Concrete Mixes, Bureau of Indian Standard, New Delhi.

Concrete mix design using copper slag as fine aggregate

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Concrete mix design using copper slag as fine aggregate