Copper Slag Content Research Articles

Compaction and shear strength enhancement of weak soil by copper slag addition

Industrial explosion not only put thrust to the resource exploitation but also produces lot of wastes that need proper disposal. This is being researched at various levels and domains, Civil engineering industries also help in utilization of various industrial wastes such as fly ash, slags, industrial plant processed wastes etc in the construction process. Copper slag is one of the industrial by product produced which need to be disposed properly or reused. Copper slag is naturally enriched with iron silicates, calcium oxide, and alumina, with lesser quantities of copper, lead, zinc, and other metals. In this study, Natural Alluvial soil is added with copper slag of 1 and 2% proportions to that of its total weight for stabilization. Soil samples with and without copper slag is studied to obtain the tensile strength and load carrying capacity. It is found that increasing the content of copper slag in the soil increases the tensile strength multiple times and also there is considerable amount of increase in CBR. The soil shows resistance to penetration with the increasing content of copper slag, which is evident in this study, hence copper slag upto 3% is found to be effective in enhancing soil strength characteristics.

Effect of copper slag and granite dust as sand replacement on the properties of concrete

Abstract The copper slag is a by-product of copper manufacturing process, which is available in very large amount. Also the stone industries in Maharashtra produces large amount of wastes from ornamental works. Mainly granite is used on large-scale for various purposes and in this process a large amount of granite dust (GD) is wasted. An attempt is made here to reuse this waste material into concrete along with the copper slag (CS) as a sand replacement to reduce the use of natural sand. And also it will partially decrease the burden on natural resources. In this paper the effects of hardened properties of concrete with CS and GD as partial replacement of sand for 7, 28, 56 and 112 days is shown. The results indicate that, strengths of concrete containing CS and GD increases with increase in the CS and GD content. Natural sand when partially replaced in the concrete, it directly influences the economy in construction. It also gives the environment friendly disposal of industrial wastes and thus it boosts the use of industrial wastes.

Collaborative design of cement-based composites incorporated with cooper slag in considerations of engineering properties and microwave-absorbing characters

“Waste materials” possess “new utilization” for that the application of copper slag (CS) instead of natural sand can impart excellent engineering properties and exceptional microwave absorption characters to cement-based composites. In this work, natural sand was replaced in volume by copper slag to design and prepare cement mortars with different copper slag contents (10%, 30%, 50%, 70% and 100%). The mechanical properties, workability, durability and microwave-absorbing characters of mortars were tested and evaluated by the response surface methodology (RSM) and grey entropy correlation analysis to perform a collaborative analysis; and finally, optimal copper slag content was recommended. The prediction model constructed by RSM shows that mechanical properties can be mostly optimized when the conditions were set to water/cement ratio of 0.6, copper slag content of 46% and copper slag fineness modulus of 2.77. Copper slag can obviously affect workability and durability of mortars, which can be mainly due to its irregular shape and low water absorption rate. Furthermore, the microwave-absorbing characters of mortars can vary with copper slag content. The mortar with 50% copper slag content achieves the minimum reflectivity and the maximum effective bandwidth. The roughness, water absorption and content of copper slag should be given priority when applied in microwave-absorbing building engineering. Copper slag makes a dominant contribution to mortars when its content reached 50%, which can be recommended as the optimal copper slag content incorporating into cement-based composites.

Strength and durability studies on slag cement concrete made with copper slag as fine aggregates

The current investigation is an attempt to perform the strength and durability studies on slag cement concrete prepared by using copper slag (CS) as a fractional/full replacement for natural fine aggregates (FNA). Tests were performed for compressive strength, split tensile strength, acid attack, sulfate attack, water absorption, and voids. The degree of replacement of natural fine aggregates with copper slag was put at 20%, 40%, 60%, 80%, and 100% by volume. A control mix containing 100% natural fine aggregates were also prepared for comparison. The strength and durability of slag cement concrete mixes having varying copper slag content were analyzed based on the results. A considerable rise in compressive strength of concrete having a 40% copper slag fraction when compared to control was also observed. However, compressive strength declined beyond 40% substitution as a result of excess free water and was lowest for 100% substitution. The tensile strength exhibited similar behavior to that of compressive strength. On acid and sulfate exposure, change in mass accompanied by a reduction in compressive strength was shown by all concrete mixes. The results showed a decrement in water absorption with an increment in copper slag fraction up to 40% of natural fine aggregates. On further increment in copper slag fraction, a rapid increase in absorption was observed due to an increase in void content in concrete. Water absorption showed a similar trend to that of percentage voids. Therefore, the use of copper slag up to 40% fraction of natural fine aggregates is recommended to derive a concrete with sound strength and durability characteristics.

Mechanical and gamma-ray shielding properties and environmental benefits of concrete incorporating GGBFS and copper slag

Ground granulated blast furnace slag (GGBFS) and copper slag (CS) are industrial waste by-products, which are mostly discarded in landfills. Alternatively, they can be used in concrete production to reduce the consumption of cement and natural aggregates. One of the applications that can benefit from heavy-weight aggregates such as CS, is concrete tailored for radiation shielding purposes. However, there was no prior study on effect of combined use of CS and GGBFS on radiation shielding capability of concrete. This study is aimed to address the effect of GGBFS and CS content on gamma-ray shielding and mechanical performance of high-density concrete. For this purpose, concrete mixes were prepared with different percentages of GGBFS (0–60%) and CS (0–100%) as a partial replacement of cement and natural fine aggregate, respectively. The workability, compressive strength, splitting tensile strength, and radiation shielding capability of concrete mixes subjected to 137Cs and 60Co point sources were evaluated. Based on the test results, the workability of fresh concrete was enhanced (up to 63%) with increasing replacement ratios of GGBFS and CS. The optimum compressive and splitting tensile strengths were obtained by incorporating 30% GGBFS and 50% CS, which were about 20% higher than that of the control mix. The linear attenuation coefficient increased slightly with GGBFS content. On the other hand, the use of heavyweight CS aggregates increased the linear attenuation coefficient by up to 31%. Results showed that concrete made with 60% GGBFS and 100% CS exhibit superior radiation shielding capability and satisfies the strength requirements for structural applications. Therefore, it is suitable for radiation shielding of structures such as healthcare centers. Finally, the ecological analysis revealed that the concrete made with recycled materials is Eco-friendlier and contributes to sustainable development of construction industry.

Recycling copper slag in steel fibre concrete for sustainable construction

Although industrialization has raised the living standard of human beings but now it is also becoming threat to the environment. The manufacturing industries are producing waste material in large volumes and are emitting greenhouse gases. These waste materials are being dumped on open land that pollute the soil, water, and air. On the other hand, construction industry is using natural resources on large scale to create infrastructures. This has put some natural resources on the verge of fading. River sand is one of the such stressed natural resource which needs immediate researcher’s attention. Through this research work, utilization of copper industry waste material called copper slag has been tried as a substitute of sand in fibre concrete containing 1% hook end steel fibres. The aspect ratio of steel fibre used in this work was 80. It was found that workability of fresh steel fibre concrete increased linearly on inclusion of copper slag. The compressive strength of steel fibre concrete enhanced on inclusion copper slag as replacement of sand. At 28 days, concrete mixture containing 1% hook end steel fibre and 80% copper slag displayed optimum compressive strength of 44.25 MPa against 31.04 MPa of control concrete. At 7, 28 and 56 days, compressive strength of concrete mixture made with 100% copper slag was 32.64, 26.71 and 24.71% higher than that of reference concrete, respectively. Similar trend of enhancement in split tensile strength of fibre concrete with copper slag was observed. At 28 days, concrete mixture containing 80% copper slag displayed 48% and 14.72% higher split tensile strength and bond strength than that of control concrete, respectively. On use of 80% copper slag as substitute of sand, water penetration depth and capillary water absorption of fibre concrete reduced by 25.5% and 42.65%, respectively. Water penetration depth and capillary water absorption reduce almost linearly with increment in copper slag content. The present work establishes that inclusion of copper slag as replacement of sand densify the microstructure of fibre concrete.

Flexural behaviour of steel fibre reinforced concrete beams made with copper slag as partial fine aggregate replacement

Lately, development of concrete using industrial byproducts has garnered major significance in the construction industry in order to overcome problems associated with depleted natural resources. As, river sand is costly and also large scale exhaustion of these sources generates environmental harms, a substitute or replacement product for concrete industry is very indispensable. In such a situation, the copper slag can be proposed as an alternative to the river sand, which is an industrial by-product obtained from the manufacturing of copper. The present investigation assesses the incorporation of copper slag in concrete (CSC). In this paper, experimental investigations are carried to understand the flexural characteristics such as such as first crack, ultimate load carrying capacity, maximum crack width and deflection at service load and at centre of steel fibred copper slag mixed under-reinforced concrete beams. Results showed that the compressive strength of concrete decreases as copper slag content increases beyond 40%. The reduction in compressive strength beyond 40% replacement of river sand due to the increase in free water content in concrete mixes due to the low absorption properties of copper slag which can cause excessive bleeding at higher copper slag content. The load-deflection behaviour of under-reinforced, normal and copper slag concrete beams is witnessed to be alike apart from the increased values of ultimate failure loads and ultimate deflections at failure in steel fibred copper slag concrete beams.

Leaching behavior of copper slag aggregate cement-mortar by atomic absorption spectroscopy (AAS)

Leaching behavior of copper slag aggregate cement mortar was analysed using atomic absorption spectrometry (AAS)with different mix proportion immersed in two aqueous fluids: conventional water and ammonia nitrate solution. Four types of cement-mortar mix i.e. M-type, S-type, N-type and O-type were cast with constant water/cement ratio to study the leaching effect with total replacement of natural fine aggregate with copper slag. Compressive strength test of hydraulic cement-mortar along with sorptivity test of all cement-mortar mix was also conducted. Experimental results of leaching study showed minimal leaching of copper slag incorporated cement-mortar for all proportion after 95 days of subjection to two aqueous fluids. Improved compressive strength was observed for all types of cement-mortar mix and also found to be increased with higher curing age. Rate of water absorption was found to be decreased with increased content of copper slag in cement-mortar for all mix proportion.

Mechanical properties, pozzolanic activity and volume stability of copper slag-filled cementitious materials

Copper slag is a by-product waste during copper pyrometallurgy. The piling-stack of copper slag not only occupies a large quantity of plowland, but causes potential danger for local residents. In order to reduce the storage of copper slag, this study prepared concretes by replacing ordinary cement by copper slag. The mechanical properties, phase composition, micrographs, pozzolanic activity and volume stability of the compound cementitious materials were evaluated with fly ash as control. It was found that when the content of copper slag was 5%-10%, the best mechanical properties of concretes were obtained. The phase composition of hydration products of copper slag and fly ash based cementitious materials was almost identical. The micrographs and pozzolanic activity showed that copper slag had stronger reactivity than fly ash. Copper slag based pastes had good volume stability. Copper slag presented a potential application in mortars and concretes.

Steel fibre-reinforced high-strength concrete incorporating copper slag: Mechanical, gamma-ray shielding, impact resistance, and microstructural characteristics

Copper slag (CS) is a hazardous by-product of copper manufacture and its disposal has resulted in serious environmental issues. In this study, the gamma-ray shielding capacity and impact resistance as well as the density, mechanical and microstructural properties of concrete mixes in which natural sand was partially replaced with CS at 20%, 40%, and 60% (by weight) were evaluated. The mixes were prepared with water to binder (w/b) ratios of 0.35 and 0.40. Steel fibres (SF) were also incorporated at volume fraction of 1.0%. As expected, mixes with a higher w/b ratio showed higher workability and lower strength and radiation shielding properties. The mechanical properties were improved with increasing replacement ratios of CS. The compressive strength of CS concrete increased by 5–12% relative to that of the control concrete. SF-reinforced concrete showed 27% and 25% higher splitting tensile and flexural strengths, respectively, compared to those of the counterpart unreinforced concrete. The linear attenuation coefficient of concrete specimens subjected to IAEA 137Cs (662 keV) point source was higher in mixes with lower w/b ratio and higher CS content and up to 42% enhancement in the linear attenuation coefficient was obtained at CS content of 60% and w/b ratio of 0.35. However, the effect of SF was not significant. On the other hand, SF-reinforced mixes with 60% CS exhibited about 40% higher impact resistance compared to its corresponding unreinforced mix. The microstructural properties of selected mixes were studied using scanning electron microscopy (SEM). CS concrete showed a denser matrix with fewer pores compared to the control concrete. Based on the experimental results, the use of 60% CS yields the best properties of high-strength concrete; however, it increases the unit weight beyond normal-weight concrete.

Preparation and mechanical properties of steel fiber reinforced high performance concrete with copper slag as fine aggregate

High performance concrete is widely used in constructional engineering for its long durability, excellent volume stability, adequate compressive strength and good construction performance. In this paper, a class of high performance concretes are prepared by using copper slag instead of sand as a fine aggregate, and their mechanical properties are tested. Firstly, the high performance concrete specimens with different copper slag content and the steel fiber reinforced ones are individually prepared. Then, the compressive and flexural strength tests for cured high performance concrete specimens are operated according to the CECS13-2009 fiber reinforced concrete test method standard. The test results show that for the high performance concrete with copper slag as fine aggregate, the compressive strength reaches a peak value as the replacement ratio of copper slag to fine sand about 35%, but the flexural strength decreases with increasing copper slag replacement ratio, while for steel fiber reinforced high performance concrete, when the copper slag replacement ratio is about 40%, the concrete has a relatively high compressive strength, flexural strength and toughness. Furthermore, under an equivalent strength condition, the additional steel fiber improves the replacement rate of copper slag in the high performance concrete, so the steel fiber reinforced high performance concrete with copper slag as fine aggregate exhibits a better comprehensive mechanical property.

Influence of the replacement of fine copper slag aggregate on physical properties and abrasion resistance of pervious concrete

Copper slag (CS), the metallurgic slag of the copper industry, has demonstrated very promising potential as an aggregate for application in the concrete industry. The present study evaluated the hydraulic conductivity, various strengths, impact and abrasion resistance of the pervious concrete (PC) when a natural fine aggregate of dolomite was replaced by the CS at levels of 0%, 20%, 40%, 60%, 80%, and 100% by the volume of the natural fine aggregate. The optimum content of CS leading to the highest mechanical properties was 100%. At this percentage, compressive, flexural, and split tensile strength for the samples at 28-days curing ages represented 31%, 17%, and 10% increase compared to the control sample. Besides, at this percent, the surface abrasion resistance and weight loss due to impact and ravelling were 23.6% and 21%, respectively, lower than neat dolomite, obtained by a wide wheel abrasion test and a Los Angeles abrasion test. The higher mechanical properties of PC was dependent to higher mechanical properties of deployed aggregate and a denser transition zone s for the CS compared to the dolomite, measured by the aggregate crushing test and the SEM observation.

Strength and micro-structural properties of self-compacting concrete incorporating copper slag

Copper manufacturing industry produces abundant quantity of copper slag as an industrial by-product. Its management and disposal poses a major challenge for the environment, thus an urgent need for its potential alternative is recommended. The intent of the current research work was to design self-compacting concrete mixes incorporating copper slag as fine aggregate replacement. Compressive strength, split tensile strength along with micro-structural analysis of SCC mixes were conducted for up to 90 days of curing. Linear Regression analysis was executed to correlate the fresh properties of SCC. Flowability and passing ability of SCC mixes enhanced as the content of copper slag increased, at constant water cement ratio and fixed quantity of superplasticiser. Compressive strength and split tensile strength increased as the content of copper slag escalated. SEM, EDS and XRD analysis confirmed the development of calcium silicate hydrate gel in concrete mixes with the progressing curing ages from 7 to 90 days. Analysis of variance (ANNOVA) was used to compare different SCC mixes at 7, 28 and 90 days of curing age. Post hoc Tukey HSB was used for multiple comparision between SCC mixes varying from 0% to 60%. Statistical analysis reported that 28-day and 90-day compressive strength was statistically significant while 7-day compressive strength was found out to statistically insignificant.

Hydration mechanisms of composite binders containing copper slag at different temperatures

The hydration mechanisms of composite binders containing copper slag at different temperatures (20 °C and 50 °C) were investigated by hydration heat determination, TG/DTG, non-evaporable water content measurement and X-ray diffraction (XRD). The compressive strengths of mortars containing copper slag cured at different temperatures were also determined. In addition to plain cement, quartz powder with a similar particle size and the same replacement ratio as copper slag was selected as the control sample. The results show that the addition of quartz powder has a slight acceleration effect on the hydration of cement, while the addition of copper slag has a strong retarding effect on the hydration of cement. The second exothermic peak of the composite binder containing copper slag is delayed as the copper slag content increases, but this trend weakens at high temperatures. The hydration heat of the composite binder containing copper slag decreases with increasing copper slag addition. Moreover, the hydration heat of the composite binder containing copper slag is higher than that of the composite binder containing an equal mass of quartz powder within 72 h. Copper slag has pozzolanic activity and consumes Ca(OH)2 in hardened paste, although the pozzolanic activity of copper slag is low. However, the pozzolanic activity of copper slag is enhanced at high temperature. Furthermore, the reaction of copper slag does not produce new crystalline products compared to those produced by cement. Moreover, compared to hardened plain cement, the hardened composite binder containing copper slag has a higher non-evaporable water content gain rate. The mortar containing copper slag also has a higher compressive strength gain rate than the mortar containing equal mass quartz powder. Although the compressive strength of mortar containing copper slag is lower than that of plain cement mortar, it is higher than that of mortar containing quartz powder.

The possibility of the application of copper slag in asphalt mixtures

Rapid industrial development over the last decades has led to the creation of a diversified industrial waste that poses serious environmental problems. On several occasions attempts have been made to increase the reuse of waste and alternative materials for the construction of civil engineering structures. One of these materials is the copper slag that is byproduct of melting and processing of copper ore. The objective of this paper is to investigate the possibility of using copper slag from RTB Bor in asphalt mixtures for wearing courses of pavement structures. For this purpose, the testing of two asphalt mixtures AB11s with different percentages of the content of copper slag, as a partial replacement of the natural aggregate, was carried out. The replacement percentage of copper slag was 25% and 50% of fractions 2/4, 4/8 and 8/11.2 mm. The obtained results were compared with the control mixture. In addition to the physico - mechanical characteristics of the slag (density, water absorption, toughness and abrasion characteristics, affinity between slag and bitumen, particle shape), the subject of this research is the design of asphalt mixtures according to the Marshall method and testing of the water resistance, stiffness and resistance to permanent deformation of asphalt mixtures with slag. The results of these tests show that asphalt mixtures with cooper slag have better water resistance, but lower resistance to permanent deformation, lower stiffness at low frequencies (high temperatures) and higher stiffness at high temperatures (low frequencies).

Investigating the mechanical and hydraulic characteristics of pervious concrete containing copper slag as coarse aggregate

In this research, the mechanical and hydraulic characteristics of pervious concrete incorporating copper slag coarse aggregate were investigated. Generally, seven main mixes including 0%, 20%, 40%, 50%, 60%, 80%, and 100% replacement of dolomite aggregate with copper slag were considered in this study. The results of mechanical strength tests revealed that the highest increase in strength compared to the control mix was related to 60% replacement, in which compressive strength, flexural strength, and splitting tensile strength increased 31%, 19% and 18%, respectively. Also, the results of the Pull-off adhesion test showed that the bonding strengths of mixes incorporating 60% copper slag (median percentage) were similar to control mixes; while the bonding strength of mixes that incorporating 100% copper slag (high percentage) reduced dramatically. Moreover, the porosity and permeability of the pervious concrete were augmented with increase in the copper slag content.

Experimental Behaviour of Sandwich Panels Using Copper Slag Mortar

This paper presents the study to investigate the viability of using copper slag as fine aggregate in cement mortar. Two series of cement mortar mixtures were prepared with different proportion of copper slag at different workability. In the first series, various proportions of copper slag is substituted for sand ranging from 0% to 100% with constant workability. Second series consists of fully replaced copper slag for sand in the cement mortar, which was achieved by maintaining the same workability as that of the control mortar mixture from first series and a control mixture for this new workability with sand as fine aggregate. The strength of twelve trial cement mortar mixtures were tested. The results indicate high compressive strength upto 50% replacement of copper slag, after that the compressive strength decreases with increase in copper slag percentage in cement mortar. The copper slag content in the mortar adversely affected the compressive strength of the mortar mixtures as 4.2% and 21.1% improvement in the compressive strength of the cement mortar for 50% replacement compared and 100% replacement compared with the control mortar mixtures. The density of cement mortar increases with increase in copper slag. From these trial mixtures two optimized mixtures were selected and were used to cast the sandwich panels. This panels were tested for flexural behaviour and axial load compression behaviour. The behavior of sandwich panels were simulated using ANSYS and the results were compared with experimental results.

Influence of copper slag and metakaolin on the durability of self compacting concrete

Now-a-days, researchers are endeavoring to discover new substitute materials to elucidate the scarcity of natural aggregates in the construction industry. One such alternative is copper slag (CS) obtained as byproduct during the matte smelting process of copper metal. The present investigation is aimed to assess the durability of self compacting concrete (SCC) incorporating copper slag (CS) as fine aggregates and metakaolin (MK) as substitute to fly ash (FA). A total of seven concrete mixes were prepared. The control concrete contains 60% ordinary portland cement (OPC), 40% FA and 0% CS whereas other six mixes contains constant percentage of 60% OPC, 30% FA, 10% MK with different proportions of CS from 0% to 100%. Results revealed that fresh properties declined with inclusion of MK although escalated with increment of CS content. All SCC mixes exhibited higher compressive and splitting tensile strength in comparison to control concrete. The minimum carbonation depth was marked for 100% CS substitution with 10% MK as replacement to FA. The maximum electrical resistivity and resistance to sulfate attack were obtained for 20% CS substitution while UPV values of whole mixes were under the excellent quality of concrete beyond 7 days of curing. On full replacement of sand by CS with 10% MK, initial surface absorption and sorptivity were significantly lower than control concrete at each curing period. This study suggests that CS together with MK can be a potential substitute to natural sand in the construction sector to overcome the scarcity.

Utilization of high carbon fly ash and copper slag in electrically conductive controlled low strength material

The aim of this experimental investigation is to develop electrically conductive controlled low strength materials (CLSM) using both fly ash with high content of unburned carbon particles (HCFA) and copper slag as a fine aggregate, both of which are waste materials with low reuse rate. Various experiments, including flow consistency test, bulk density measurement, unconfined compression test, and electrical conductivity (σmix) measurement were performed on the developed electrically conductive CLSM. For comparison with the results of the developed conductive CLSM, various experiments were also performed on CLSM containing electrically nonconductive particles (low carbon fly ash (LCFA) and sand). The results of this study demonstrate that σmix of the tested CLSM specimens increases with increasing copper slag fraction in aggregate and the measured σmix of the CLSM based on HCFA is greater than that with LCFA because both HCFA (or unburned carbon particles) and copper slag are electrically conductive. The measured flow consistency, bulk density, and unconfined compressive strength (UCS) of conductive CLSM were comparable with those of nonconductive CLSM. Therefore, the electrically conductive CLSM can be developed using both HCFA and copper slag. Finally, the relationship between UCS and 1/σmix was also investigated in this study.

Investigation on electromagnetic and microwave absorption properties of copper slag-filled cement mortar

Ordinary cement mortar is a widely used structural material. However, its microwave absorbing ability is very weak due to the lack of magnetic and electrical conductive components. Copper slag is a by-product produced from copper smelting, which possesses excellent magnetic properties. In this paper, ordinary cement mortar specimens incorporated with copper slag were prepared. The electromagnetic (EM) parameters were determined by a network analyzer in 8.2–12.4 GHz frequency ranges. The reflectivity of the mortars against EM wave was evaluated through an arch reflectivity testing system in the same frequency ranges. The skin depth and compressive strength of mortars were calculated and tested, respectively. Results show that both the real and imaginary parts of permittivity increase with the increase of copper slag content and over 30% copper slag contents can evidently improve the permittivity of the mortars. Meanwhile, permeability of the mortars is evidently improved in the frequency ranges with the addition of the copper slag. The reflectivity values of the copper slag-filled mortars tend to decrease and then increase with the increase of copper slag contents. The minimum reflectivity reaches −13.4 dB and the reflectivity below −10.0 dB can be obtained in the frequency range of 8.2–8.4 and 10.4–10.9 GHz representing 90% absorption when the copper slag content is 50%. Over copper slag content can make the mortar not absorb but reflect the EM microwave. Skin depth decreases with the increase of microwave frequency and copper slag content. The mortars with 50% copper slag content exhibit higher compressive strength value, as well as better microwave absorption performance.