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Article

A Proposal for Electromagnetic Performance in Cementitious Systems: Carbon Fiber and Copper Slag

by
Hilal Demirtaş
1 and
Mustafa Dayı
2,*
1
Graduate Education Institute, Duzce University, 81600 Duzce, Türkiye
2
Department of Civil Engineering, Faculty of Engineering, Duzce University, 81600 Duzce, Türkiye
*
Author to whom correspondence should be addressed.
Buildings 2025, 15(19), 3634; https://doi.org/10.3390/buildings15193634
Submission received: 8 September 2025 / Revised: 6 October 2025 / Accepted: 7 October 2025 / Published: 9 October 2025
(This article belongs to the Collection Advances in Enhancing Properties of Concrete, Mortar, Gypsum, and Plaster Materials)
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Abstract

Exposure of individuals to electromagnetic fields in a wide area of daily life necessitated making spaces-structures healthier against electromagnetic fields. In this study, waste copper slag and carbon fibers were added to the cement mortar in different proportions with substitutes and additives. Physical, mechanical, electromagnetic shielding and microstructure studies were carried out on the produced composite mortars at different ages. It was determined that the mechanical strengths of composite mortars were superior to those of reference mortar samples. It was observed that electromagnetic shielding effectiveness was more positive with copper slag and especially carbon fiber additions. The highest electromagnetic shielding values were obtained in mortars containing 50% copper slag and 0.5% carbon fiber. Additionally, it was determined that copper slag, stored as an environmental waste, could be suitable for use in cementitious mortar systems. These composites offer promise for sustainable building designs in terms of both environmental performance and structural material stability.

1. Introduction

From the first moment humanity existed on earth, shelter has emerged as an important need. These needs have varied according to the geography in which individuals live. However, the characteristics of the structures constructed by individuals differed according to the climate characteristics of the geography in which they lived, the rock structure, the type of materials found in the region, their knowledge, lifestyles, beliefs, cultures, physical structures, etc. As a result of technological developments, advances in building materials have caused great changes in the design and construction of structures in the modern era. The discovery and use of new materials have led to the emergence of more robust, durable, energy efficient and aesthetically appealing structures.
As technology becomes more prevalent in daily life, the use of technological products by individuals has become widespread. Electronic devices such as electric trains, electrical appliances, high-voltage power lines, televisions and computers, telephones, microwave ovens, air conditioners, electric heaters, photocopiers, automobiles, base stations, electronic communication networks, satellite communication systems, radars, vehicle ignition systems, medical devices, and others create electromagnetic fields (EMF) during operation, causing this energy to be emitted. The resulting electromagnetic field and energy dissipation can harm living things and prevent the more effective and efficient use of other electronic products by creating electromagnetic interference (EMI) [1,2,3]. The extent to which electromagnetic waves are present in an environment is crucial for the proper operation of electronic devices. Therefore, the intensity of the electric and magnetic fields in the environment in which these electronic devices operate is crucial [4,5].
In large urban areas, communication intensity varies across time and space. Intense exposure to EMF can lead to several adverse effects. For example, numerous studies have shown that the adverse effects of low-frequency radiation on living organisms are greater at close range [6]. Although not adequately addressed by international organizations such as the World Health Organization, exposure to low-intensity, low-frequency electromagnetic fields poses a significant health hazard. There is strong evidence that long-term exposure to mobile phone frequencies increases the risk of brain cancer in both humans and animals [7,8].
Research supports the idea that the risk posed by electromagnetic waves can be mitigated to a certain extent by building materials. Designs that absorb or reflect high-energy radiation are currently in use. Furthermore, materials compatible with cement, such as metal fibers, iron oxides, carbon nanotubes, graphite, carbon filaments, zinc oxide, graphene oxide, and carbon fiber, can be said to have electromagnetic absorption properties. [9,10,11]. Carbon-based fibers are used for EMI shielding due to their dielectric properties and carbon’s ability to absorb and reflect electromagnetic radiation. In order to reduce the electromagnetic field effect, it becomes inevitable to make the structures healthier spaces. Among the studies conducted for this purpose, the composites developed to improve the EMI properties of the mortars used in the structures have been important.
Copper slag is a byproduct of copper production. This waste can be used as a substitute in building materials. This phenomenon is important in terms of environmental impact and sustainability. It has been reported that approximately 2.2 tons of metal waste is generated during the production of one ton of metal [12]. This demonstrates the significant environmental benefits of copper slag recycling. The chemical composition of copper waste also allows it to be used in concrete. One study indicated that copper slag could be used as an iron raw material in Portland cement production [13]. Various studies reported the use of copper slag as a fine aggregate in concrete and mortar. Copper slag found to be effective in improving the flexural and compressive strength of cement-based mortars. Furthermore, the use of copper slag in mortar and concrete at certain rates shown to provide benefits in terms of workability and strength. However, it is anticipated that high volumes may cause bleeding and rheological problems in fresh concrete, leading to a decrease in strength [14,15,16]. Luo et al. reported that the synergistic modulation of slag/fly ash industrial waste in composite mortars can be altered by the CaO/Al2O3 and SiO2/Al2O3 ratios. It was also reported that additional sodium-dominated components contribute to carbon emissions in composite geopolymer mortar production [17].
Many researchers have investigated the EMI shielding effectiveness of various materials. Various mineral additives and fibers have been used in building materials for this purpose. Metals are the most commonly used traditional EMI shielding materials. However, recently, lighter alternative materials such as polymer-based materials and ceramic-based materials have emerged [16,18,19]. Jusoh et al. investigated the EMI shielding effectiveness of various gypsum-magnetite composites in the X-band. They concluded that the addition of magnetite powder increased the overall shielding effectiveness and that this was related to the absorption and reflection of EMI by the magnetite powder [20]. Liu et al. reported that in the X-band (8.2–12.4 GHz), as electromagnetic wave frequency increases, absorption rather than reflection increases in carbon fiber paper. They attributed this phenomenon to the fact that as electromagnetic wave frequency increases, more electromagnetic waves penetrate the carbon fiber paper, resulting in a decrease in the material’s reflection coefficient [21]. EMI protection effectiveness in the range of 15 dB to 26 dB was achieved for 1 GHz in composites containing carbon nanotubes and carbon fibers [22,23,24]. In recent years, some researchers have investigated the effectiveness of EMI shielding by producing composite materials containing polypropylene, carbon, and steel fibers along with various metal oxides. Studies have reported positive results in EMI shielding at both low and high wave speeds [25,26,27].
Recent studies have attempted to increase EMI shielding capacity by using various fiber and mineral additives in composite elements. However, no studies have been reported on the shielding effectiveness of combined copper slag as an industrial waste and carbon fiber. This study is based on the investigation of the mechanical, physical, microstructural, and electromagnetic shielding properties of composite mortars using carbon fiber and copper slag.

2. Experimental Program

2.1. Materials

The used raw materials involved copper slag waste was supplied from Eti Copper Inc.-Kastamonu. Copper slags have different sizes from 1 mm to 50 mm and have a glassy structure with dark gray and black colors. Typical copper slag chemical content obtained from the plant is shown in Table 1. Copper slags were first passed through a Rantek brand jaw crusher, then ground in a UTEST brand ball mill and brought to sieve sizes compatible with sand. The sieve sizes to be replaced with sand are, respectively, 2–1 mm, 1–0.5 mm, and below 0.5 mm materials. The sieve mesh of the copper slag was adjusted in accordance with the CEN standard sand gradation. Carbon fiber with fiber length of 10–12 mm and tensile strength of 3.8 GPa was supplied from Dost Chem.-Istanbul Co. As aggregate material, CEN standard sand in accordance with EN 196-1 was used [28]. CEM II 42.5R cement produced by Bolu Cement Inc. in accordance with EN 197-1 standard was used as binder [29]. The specific surface area of the cement is 4274 cm2/g and its 28-day compressive strength is 51.4 MPa.

2.2. Sample Preparation

In the experimental study, 9 mixtures of composite mortars were produced using cement as binder, standard sand and copper slag as aggregate, and carbon fiber as fibre. Copper slags were replaced with sand in the mixtures at 25% and 50% by weight, and carbon fibers were added to the mixture at 0.1%, and 0.5% by volume. Single and double were used to determine the effect of carbon fiber and copper slag. Mortars are defined as the reference series (R) containing only sand and cement, the series containing carbon fiber in addition to the reference series (C), the series containing copper slag replaced only by sand (CS) and the series using carbon fiber and copper slag (CS/C). The proportions of the materials by weight for the mortar series are given in Table 2. Workability values were maintained constant throughout the production of the mortar series. Mixing water ratios were varied to achieve the same spreading values. No plasticizing chemical additives were used in the production of the mortar. The mortar materials were weighed on a 2000 g capacity Svock brand scale and dry-blended in a separate container. The resulting dry mix was mixed with mixing water in a UTEST brand mortar mixer at 125 RPM for approximately 1.5 min. To better mix any materials adhering to the sides of the container, the mixer was stopped periodically to homogenize the mortar, completing a total of three-minute mixing sessions.

2.3. Test Methods

Fresh and hardened mortar tests were performed on mortar samples. To determine the workability of the mortars, a flow table test was conducted on fresh mortars in accordance with EN 1015-3 [30]. Fresh mortars with a spreading value of 135 ± 5 mm, determined from the spreading table test, were placed in triple steel molds with dimensions of 40 × 40 × 160 mm. Samples from the mortar series were cured until the specified test date, then removed and kept under laboratory conditions for one day before being subjected to tests at 28, 90, and 180 days, respectively.
To determine the electromagnetic properties of the mortar series, molds were produced from 300 × 300 × 10 mm plywood. After curing in the mold for one day, the samples were removed from the mold and cured in water until the test day (Figure 1). The apparent density test of mortar samples was determined according to the principles specified in the TS EN 1015-10 standard [31]. For the mechanical properties of the hardened mortar series, tensile strength and compressive strength tests were performed on prismatic samples aged 28, 90, and 180 days in accordance with TS EN 196-1 under uniaxial load. Three samples from each series were used for the mechanical and electromagnetic shielding tests, and the average of the results was calculated. The elasticity modulus of the samples was determined using deformation-controlled compressive strength data. The elastic area in the load-deformation curve was used to determine the elasticity modulus experimentally. Scanning electron microscopy (SEM) and quantitative chemical analyses (EDS) were performed to examine the hydrated structures and void formation formed by the cement matrix of copper slag and carbon fiber in the produced mortars. SEM-EDS analyses were conducted on three selected mortar series. The analyses were performed using a Quanta FEG 250 electron microscope at the Düzce University Scientific and Technological Research Application and Research Center.

Electromagnetic Wave Shielding

Electromagnetic waves travel at the speed of light without loss. The EMI shielding effectiveness (SE) of a shielding material is defined as the ratio of transmitted energy to incident energy. Shielding of an EM wave occurs through three mechanisms: reflection loss (at the surface), absorption loss (through the shield), and multiple internal reflections (inside the shield) [32]. SE-shielding effectiveness indicates the attenuation intensity of an electromagnetic wave in transition to another medium after interacting in one medium [33]. Mortar plates measuring 300 × 300 × 10 mm were used to measure electromagnetic shielding. The plates continued to cure until the test day. Before the test day, they were removed, dried in an oven, and subjected to the test. Electromagnetic permeability tests were conducted in the Building Materials Laboratory of the Civil Engineering Department, Faculty of Engineering, Karabuk University. The experiments were conducted using a 4060 RF generator and two spectrum analyzers using the MCS Spectrum Analyzer program, as shown in Figure 2. The measurement frequency range for the mortar plates was maintained between 900 MHz and 6 GHz, and electromagnetic transmission data were obtained in dB units at 100 MHz by the MCS Spectrum Analyzer software (V2.1.6.).

3. Result and Discussion

3.1. Measurement Results of Physical and Mechanical Properties of Mortar Samples

Experiments were conducted to determine the apparent density and water absorption properties of mortar samples resulting from the fracture of the mortar samples during compression testing. Figure 3 shows the apparent density and water absorption values of mortar samples cured for 28 days. The apparent density values for mortars containing copper slag were higher than those for other mortar samples. However, these values decreased with an increase in carbon fiber volume. As expected, the unit weight and pore structure of the material in the mixture were influential in this.
Among the unit volume weight values of the mortar series, the lowest value was obtained in the 5C series with 1.98 g/cm3, while the highest value was obtained in the 50CS series with 2.55 g/cm3. When compared with the reference sample, the highest apparent density of the 50CS series increased by 14.35%, while the lowest apparent density of the 5K series decreased by 11.21%. The decrease in apparent density with increasing fiber content and the increase in copper slag suggest similar results to other studies [34]. In water absorption test data, the low water absorption nature of copper slag resulted in lower water absorption in the 50% copper-added series. Chakrawarthi et al. stated that copper slag, a material with low water absorption, also contributes positively to machinability due to this property [35].

3.2. Measurement Results of Mechanical Strength

Flexural tensile and compressive strength tests were conducted on hardened mortar samples measuring 40 × 40 × 160 mm, produced for mechanical properties in the mortar series. The obtained data are shown in Figure 4 and Figure 5. The effects of copper slag and carbon fiber on the 28- and 90-day flexural tensile strength are shown in Figure 4. An increasing trend in flexural tensile strength was observed in all mortar series. In the single-additive series, copper slag was found to provide higher strength values than reference series. A similar trend in strength increases was observed in the 25CS/C and 50CS/C series. With 25% and 50% increases in copper slag, strength increases of 14% and 24% were observed. In the flexural tensile strength data, it was observed that the 28-day values ranged between 6.15 and 10.84 MPa, while the 90-day values ranged between 8.77 and 10.97 MPa. At the end of 90 days, the lowest flexural tensile strength was observed in the reference sample with 8.77 MPa, while the highest strength was observed in the 50CS/1C series with 10.97 MPa.
Tensile strength in bending is relatively low in series containing low carbon fiber, while flexural strength increases in series containing high carbon fiber. Data obtained are consistent with other similar studies. Significant increases in both flexural and compressive strengths were observed in mortars containing copper slag [13,36,37].
Figure 5 shows the compressive strength values of the mortars produced as a result of different proportions of copper slag replacement and carbon fiber addition. In all series, a linear increase in compressive strength values was observed in the series as the days passed. It was observed that the 28-day compressive strengths ranged from 47.35 to 66.76 MPa, the 90-day data ranged from 60.12 to 79 MPa, and the 180-day data ranged from 58 to 80.06 MPa. In the compressive strength graph, the 28-day strengths of the 25CS and 50CS series, which included copper slag, were relatively similar. It was observed that the strength in the copper slag-added series increased at older ages compared to the reference series. Conversely, the strengths of the 50CS series mortars remained unchanged at 90 and 180 days. It can be said that this increase in the series caused by copper slag substitution has also been observed in other studies and is due to the structural durability of copper slag. [38]. It has been determined that copper slags have a high friction angle due to their sharp angular shapes, thus increasing the mechanical strength of the materials [39]. The compressive strength values of the samples with carbon fiber added were observed to be lower than the reference sample strength for all days. This is likely related to the void structure created by the fibers. Similar strength reductions have been observed in other studies. It is noted that increasing the amount of fiber increases the air content within the structure, thus decreasing strength accordingly [37]. Carbon fibers were found to be ineffective in compressive strength but effective in tensile strength in bending. This can be explained by the fact that the fibers can withstand bending stresses but cannot resist compressive stresses [40]. Carbon fibers are known to increase porosity, primarily by delaying hydration reactions and trapping air, which is detrimental to the composite, while exhibiting improvements in deformation resistance and energy absorption despite strength degradation [41].
The modulus of elasticity is the ratio of the deformation occurring below the uniaxial compressive strength and is an important mechanical parameter. This modulus reflects the material properties of the composite mixture and is also affected by its physical properties. Static modulus of elasticity values obtained from stress–strain curves are presented in Figure 6. It was determined that the 28-day elastic modulus values were close to each other and varied between 2 GPa and 2.5 GPa. The variation pattern in the 25CS and 50CS copper slag series exhibited a distribution inversely proportional to the porosity values. Increasing copper slag replacement, on the one hand, increased the compactness and modulus of elasticity of the mortar by filling the internal pore structure. In addition, unlike other studies, a decrease in elasticity modulus values was observed with increasing carbon fiber volume within the mortar. This decrease is thought to be due to the fiber length effect [42]. The Emod values of the long-cured samples were determined to range from 4.31 GPa to 6.0 GPa. While modulus of elasticity values increased with copper slag content, they decreased inversely with carbon fiber content. An increase in flexural tensile strength, modulus of elasticity, and ductility was observed with the incorporation of carbon fibers into the mortar matrix. However, this increase was reversed with the use of high fiber concentrations. This increase is attributed to the bridging effect of the fibers and the shear strength at the cement paste-fiber interface [43,44].

3.3. Measurement Results of EMI Shielding Effectiveness

Electromagnetic shielding mechanism includes the reflection or absorption of radiation and multiple reflections occurring at interfaces outside of these. Cementitious materials are slightly conductive, so the use of a cement matrix allows the conductive fillers in the mortar to be electrically connected even if they are not touching each other [22,45]. Electromagnetic shielding tests were carried out in 11 different frequency ranges ranging from 1 GHz to 6 GHz on 56-day-old 30 × 30 × 1 cm mortar plates. Electromagnetic shielding effectiveness of composite mortars were shown in Figure 7.
In all series, increased copper slag and carbon fiber additions were observed to have positive effects on electromagnetic shielding effectiveness. The copper slag addition was found to be more effective than the reference series in the frequency range of 1.5 GHz to 3.5 GHz. It can be assumed that increasing the copper slag content in the mortar does not significantly impact shielding effectiveness and is more effective in the low-frequency range. The results obtained are consistent with other studies, and this study also found that the effect is higher at low frequencies [46]. The shielding effectiveness of the 1C-coded mortars containing 1% carbon fiber was found to be 38% higher on average compared to the reference series. In the 5C-coded mortars containing 5% carbon fiber, the shielding rate reached 84% compared to the reference series.
Figure 7b shows the shielding effectiveness of copper slag and carbon fiber in dual use. It was observed that the dual use of these materials produced different results in shielding effectiveness. Increasing the copper slag content and containing 1% carbon fiber resulted in a decrease in shielding effectiveness at low frequencies in the 25CS/1C and 50CS/1C series. At low frequency (900 MHz), the effectiveness was measured as −18.72 dB for the reference sample, while effectiveness was measured as −25.15 dB for 25CS/1C and −31.94 dB for 25CS/5C. It was observed that the transmission losses observed in the low frequency range were also effective at high frequencies. When values above 4 GHz are examined and compared with the reference sample, the 25CS/1C series provides 32% better shielding, while the 25CS/5C series provides 102% better shielding. The effectiveness of carbon fibers in shielding EM waves is similar to the results of previous studies. In a study conducted by Chiou and colleagues, they achieved an average shielding efficiency of 10 dB using short carbon fibers in cement mortars [46].
In the series containing 0.1% and 0.5% carbon fiber, the effectiveness at the 900 MHz frequency was −18.72 dB for the reference sample, −25.76 dB for the 50CS/1C series, and −32.91 dB for the 50CS/5C series. At the 6 GHz frequency, the effectiveness was −25.96 dB for the 50CS/1C series, while the effectiveness increased to −40.66 dB for the 50CS/5C series. The highest shielding was measured at −42.01 dB for the 50CS/5C sample at a frequency of 5.4 GHz. Figure 7 is examined, the positive effect of carbon fiber on shielding is clearly determined at almost all frequencies. When all series are compared, it is observed that the shielding effectiveness increases with the use of copper slag and carbon fiber in the mortar mixture. It has been determined that shielding effectiveness increases with increasing carbon fiber content in the mortar, and this finding is consistent with other studies [47]. When the transmission loss is examined in all series, it is seen that the highest transmission loss is in the 50CS/5C sample containing 0.5% carbon fiber and 50% copper slag. It has been determined that the 50% copper slag content together with carbon fiber provides good shielding. In a study where copper slag was used as a substitute in different proportions, it was stated that copper slag is beneficial in terms of improving radiation absorption performance, not reflection [48].

3.4. Microstructural Characterization with SEM

Microstructure studies were carried out using scanning electron microscopy (SEM-EDS) to examine the interface of carbon slag and carbon fiber with the hydrated structure for some selected series among the nine mortar series produced. In the microstructure examination of the reference sample in Figure 8, compact and dense hydrated structures were observed around the aggregate. This compact hydrated structure resulted in high mechanical properties in the mortars.
Figure 9 shows the SEM image and microchemical analysis (EDS) images taken from two points of the 5C series. Carbon fiber grains with diameters of 7–8 microns are visible in this series, which consists of 0.5% carbon fiber, cement, and sand. In the EDS analysis at point 1, hydrated calcium silica structures originating from the cement are observed, while in EDS analysis 2, only a carbon peak is observed. An examination of the SEM image reveals that the cement matrix has bonded with the carbon fiber, and the fibers are dispersed within the matrix without agglomeration. The EDS analysis revealed the formation of a hydrated structure around the carbon fiber. Figure 10 shows the SEM image and two EDS analyses of the 50CS/5C series, which contains 50% copper slag and 0.5% carbon fiber. It is clear that the copper slag is regularly distributed in the mortar matrix and there is no interface separation with hydrated structures. In addition, it was observed that the structure around the fiber contained fewer cracks in the series containing copper slag and carbon fiber. When the carbon fiber content is too high or the length is insufficient, the bonding effect of the cement-based product may be reduced, leading to a decrease in strength in the C series. This effect on carbon fiber has also been reported to occur in composite structures containing basalt fiber [43].

4. Conclusions

The experiments performed on the samples produced by substituting copper slag and carbon fiber into the mortars were carried out in order to determine the mechanical, physical, electromagnetic transmission and microstructure properties of the mortars. The results and recommendations obtained as a result of these experiments are presented below:
  • In mortar series, an increase in unit volume weight was observed with the replacement of copper slag, while a decrease in unit volume weight was observed in mortar series with carbon fiber reinforcement. This increase and decrease in the series can be explained by the higher density of copper slag and the relatively low density of carbon fiber.
  • Static elasticity modulus values have decreased with carbon fiber substitution and have shown a significant increase with copper slag substitution. As the curing time increases, the elasticity modulus values increase due to the hydration process. Carbon fibers increase the porosity rate and reduce the mechanical properties Copper slag, an industrial waste, reduces porosity and increases mechanical strength. When carbon fiber and copper slag are used together, the increase in copper slag contributes to the increase in compressive strength, while keeping the slag ratio constant and increasing the carbon fiber ratio has led to a decrease in compressive strength.
  • Shielding effectiveness increased with the use of carbon fiber in the mortar at a volumetric rate of 5%. An average shielding effectiveness of 35 dB was achieved at low frequencies and 30 dB at high frequencies. Substituting copper slag at 25% and 50% resulted in a relative increase in shielding effectiveness. This increase was particularly effective at low frequencies. Substituting 50% copper slag and 5% carbon fiber can significantly increase shielding effectiveness, particularly at high frequencies.
  • Considering its contribution to sustainability, the utilization of copper slag in the construction sector, which has a wide scope, will benefit the environment. Additionally, it should be noted that due to the dense structure of copper slag, it can also be evaluated as a substitute for aggregate in heavy mass concrete.

Author Contributions

All authors of this paper have made objective contributions within the scope of their respective job responsibilities, as detailed below: Conceptualization, H.D. and M.D.; methodology, H.D. and M.D.; validation, M.D.; Formal analysis, H.D. and M.D.; investigation, H.D. and M.D.; resources, H.D. and M.D.; data curation, H.D. and M.D.; writing—original draft preparation, H.D. and M.D.; writing— review and editing, H.D. and M.D. All authors have read and agreed to the published version of the manuscript.

Funding

The research was not funded.

Data Availability Statement

The data presented in this study are available on request from the corresponding author and some of the data will be used subsequently for analyzing other research questions.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Mortar preparation and tests (a) Steel sample molds, (b) Electromagnetic shielding samples, (c) Spectrum analyzer.
Figure 1. Mortar preparation and tests (a) Steel sample molds, (b) Electromagnetic shielding samples, (c) Spectrum analyzer.
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Figure 2. Electromagnetic wave shielding test setup.
Figure 2. Electromagnetic wave shielding test setup.
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Figure 3. Apparent density and water absorption of mortars at 28-day curing ((a) Single effect (b) Multiple effects).
Figure 3. Apparent density and water absorption of mortars at 28-day curing ((a) Single effect (b) Multiple effects).
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Figure 4. Changes in tensile strength depending on CS and C content.
Figure 4. Changes in tensile strength depending on CS and C content.
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Figure 5. Changes in compressive strength depending on CS and C content ((a). Single effect. (b). Multiple effects).
Figure 5. Changes in compressive strength depending on CS and C content ((a). Single effect. (b). Multiple effects).
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Figure 6. Effect of copper slag and carbon fiber on elasticity modulus ((a). Single effect. (b). Multiple effects).
Figure 6. Effect of copper slag and carbon fiber on elasticity modulus ((a). Single effect. (b). Multiple effects).
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Figure 7. Electromagnetic shielding effect of mortar ((a). Single effect. (b). Multiple effects).
Figure 7. Electromagnetic shielding effect of mortar ((a). Single effect. (b). Multiple effects).
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Figure 8. SEM micrograph of the reference sample at 500×.
Figure 8. SEM micrograph of the reference sample at 500×.
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Figure 9. SEM micrograph and EDS analysis of the 5C series (5000×).
Figure 9. SEM micrograph and EDS analysis of the 5C series (5000×).
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Figure 10. SEM micrograph and EDS analysis of the 50CS/5C series. (5000×).
Figure 10. SEM micrograph and EDS analysis of the 50CS/5C series. (5000×).
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Table 1. Chemical and physical properties of copper slag.
Table 1. Chemical and physical properties of copper slag.
Chemical properties
Compound (%)Element (%)
SiO235.25Cu0.76–0.03
Al2O32.54Co0.19
Fe2O359S0.40–2.31
CaO1.58Au(mg/lt)-
Na2O0.75Ag(mg/lt)6.44
K2O0.33SiO226.89
SO30.16
CuO0.53
Physical properties
Density (g/cm3)3.69
ColorDark gray
Table 2. Mix ratio of composite mortars by weight.
Table 2. Mix ratio of composite mortars by weight.
Sample CodeCement
(g)		Water
(mL)		Sand
(g)		Carbon Fiber
(g)		Copper Slag (g)
2–1
(mm)		1–0.5 (mm)0.5–0
(mm)
R445.07222.481334.87----
25CS445.07222.481001.14-164.19164.19164.19
50CS445.07222.48667.44-328.38328.38328.38
1C444.94222.41334.461.62---
5C444.5222.21333.28.1---
25CS/1C444.94222.41000.81.62164.13164.13164.13
25CS/5C444.52222.2999.98.1163.98163.98163.98
50CS/1C444.94222.4667.231.62328.27328.27328.27
50CS/5C444.52222.2666.68.1327.97327.97327.97
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Demirtaş, H.; Dayı, M. A Proposal for Electromagnetic Performance in Cementitious Systems: Carbon Fiber and Copper Slag. Buildings 2025, 15, 3634. https://doi.org/10.3390/buildings15193634

AMA Style

Demirtaş H, Dayı M. A Proposal for Electromagnetic Performance in Cementitious Systems: Carbon Fiber and Copper Slag. Buildings. 2025; 15(19):3634. https://doi.org/10.3390/buildings15193634

Chicago/Turabian Style

Demirtaş, Hilal, and Mustafa Dayı. 2025. "A Proposal for Electromagnetic Performance in Cementitious Systems: Carbon Fiber and Copper Slag" Buildings 15, no. 19: 3634. https://doi.org/10.3390/buildings15193634

APA Style

Demirtaş, H., & Dayı, M. (2025). A Proposal for Electromagnetic Performance in Cementitious Systems: Carbon Fiber and Copper Slag. Buildings, 15(19), 3634. https://doi.org/10.3390/buildings15193634

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