Brass-coated Steel Research Articles

High-conductivity cementitious composites suited for flooring applications: Effect of mixing methods and utilization rates of conductive materials

The objective of this study is to develop cementitious electrostatic discharge composites suited for flooring applications with the lowest amount of conductive material using the most appropriate mixing method. For electrical conductivity, milled carbon fiber (MCF), carbon fiber (CF), and brass-coated steel fiber (SF) were incorporated into the cementitious matrices with ratios increasing from 0 to 1% at 0.1% intervals, by the total weight of the binder. To address the homogenous distribution of conductive materials, first (F), synchronous (S), and latter (L) admixing methods were used. Reaching high early strength was another aim of the study. Flow diameter, electrical resistance (ER), compressive strength measurements, and SEM/EDX analyses were performed. According to the experimental results, the ER has a decreasing trend with the increasing fiber ratio in the matrices. CF- and MCF-based mixtures are of adequate electrical performance (10–1000 kΩ) according to related standards after 180-day measurements. No clear percolation thresholds are available for SF- and MCF-based composites up to a 1% utilization rate. Adequate electrical performance can be obtained from CF-based composites at the percolation threshold of 0.6% when prepared by the synchronous admixing method and 0.3% by the latter admixing method. Considering the CF-based mixture incorporating 0.3% CF and prepared by the latter admixing method, the flow diameter is 39.75 cm, 1-day compressive strength is 38.1 MPa, and 180-day ER is 104.15 kΩ in the long term. In conclusion, it is possible to manufacture cementitious composites with significantly improved electrical performance suitable for flooring applications with low cost, high early strength, and good fluidity ready for on-site use.

Influence of print speed and nozzle diameter on the fiber alignment in 3D printed ultra-high-performance concrete

The limitations in the available reinforcing methods have accompanied the increasing popularity of 3D Concrete Printing (3DCP). Incorporating steel fibers as reinforcement is a promising approach to overcome these limitations. However, the impact of the printing process on the alignment of these fibers is not well understood. Therefore, the objective of this research is to quantitatively analyze the distribution of steel fiber alignment in 3D printed concrete. To achieve this, digital image analysis was employed to assess the influence of nozzle diameter, print speed, and fiber content on fiber alignment in both mold-cast and 3D-printed samples. UHPC matrix without fiber addition and fiber reinforced UHPC composites with brass-coated steel fiber contents of 1.5% and 3% by volume fraction were printed. Furthermore, Material nozzles ranging from 10 mm to 40 mm in size were employed and printing speeds of 15, 25, 35, and 45 mm/s were adjusted. Subsequently, the study examined the implications of fiber alignment on the hardened performance of printed specimens and compared them with conventionally mold-cast samples. The findings of the study demonstrated that increasing the fiber content and using smaller diameter nozzles during the printing procedure led to significant improvements in fiber orientation along the printing direction. As a result, the mechanical performance of the printed samples showed a substantial enhancement compared to the specimens produced through mold casting, primarily due to the improved fiber alignment.

Enhancement of resource recovery from retired tires: Extraction of copper and zinc resources

The disposal of scrap rubber, represented by retired tires, has achieved industrial achievements, but the handling of brass-coated steel wire as a structural reinforcement in retired tires has received little attention. A feasible and efficient method of acquiring economical resources is proposed to extract copper and zinc (Cu-Zn) from brass-coated steel wire. With 20% ammonia, 10% hydrogen peroxide, and a liquid-solid ratio of 10, the brass coating almost completely dissolved in 5 minutes. This technique may remedy the challenge of weak dissolving efficiency brought on by the dual phase microstructure of brass. Electrochemical measurements and density functional theory (DFT) simulations assist in verifying that hydrogen peroxide decreases the resistance of the corrosion and that OH- and O-2 in solution are the main contributors to the dissolution. In addition, the AH effectively enhances the corrosion of the α phase in brass, which is notably evident in comparable works. This effective strategy broadens the application of retired tires and provides a new method for extracting Cu-Zn resources.

Finite element modelling and analysis of brass coated steel fibre reinforced concrete beams

The study's objective was to use brass-coated micro steel fibre to improve the strength and flexibility of beams. Steel fibres with a brass coating are resistant to corrosion and improve the fracture resistance and tensile strength of the concrete, making them appropriate for use in the building and construction industry, refractory industry, rocket launch pads, airport runways and highway pavements etc. In this work analytical research on the flexural behaviour of RC beams with brass-coated steel fibre reinforcements is presented. The beams were modelled and analysed using the Abaqus FEA software. Five beams total with various fibre volume percentages (Vf = 0, 0.5, 1, 1.5, 2) were examined for this purpose. The beam cross sections were 1000 mm in length, 100 mm broad, and 150 mm deep. The analytical results show that addition of 2.0% volume of fibres exhibited better performance. When compared to the reference beam, the increase in maximum load and deflection was found to be 36.3% and 61.84%, respectively. The load–deflection and fracture patterns of different beams were compared with the experimental and analytical responses. Amongst the two approaches, it demonstrates good agreement across the whole range of loading. Thus, the deflections obtained from both the methods are ‘very close to each other’ and within ‘generally acceptable limits (say10%)’. Modeling and evaluating the structural parts can be done much more quickly and affordably using the Finite Element Analysis (FEA).

Engineering properties of different fiber-reinforced metakaolin-red mud based geopolymer mortars

In this research, fiber reinforced metakaolin-red mud based geopolymer mortar was produced by using recycled concrete aggregate and industrial waste glass powder as filler materials. Three different types of fibers were used to reinforce the geopolymer mortar, namely brass-coated steel fibers, polyamide fibers, and polyethylene fibers, with four different proportions by volume (0.25%, 0.5%, 0.75%, and 1.00%). Experiments for compressive strength, flexural strength, splitting tensile strength, flexural toughness factor, ultrasonic pulse velocity, and abrasion resistance were conducted to investigate the influence of fibers on mechanical properties. Specific gravity, porosity, and water absorption tests were conducted to examine the physical properties. Additionally, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analyses were performed. The results indicate that 50% replacement of recycled concrete aggregate and glass powder as filler material yielded the optimum strength properties. Moreover, addition of fibers enhanced the strength properties of the geopolymer mortar, for instance, the mixture having polyethylene fibers with a fiber volume of 0.75% improved the flexural strength up to 48.72%, and the mixture containing steel fibers with a fiber fraction of 0.25% showed the highest value of splitting tensile strength and improved up to 40% when compared to non-fibrous control mixture. Polyethylene fiber-reinforced mixture showed a notable toughening impact and showed a flexural toughness factor up to 66.29% more than the control sample. The reason of this improvement is because of the bridging effect of fibers. According to the findings, the 0.25% steel fibrous samples showed the best result in terms of minimum weight loss due to abrasion and showed 36.08% more abrasion resistance compared to non-fibrous control mixture. Moreover, increase in porosity was observed in fiber-reinforced mixtures. The lack of CaO content is found responsible for poor mechanical strength and bending performance of fibrous metakaolin-red mud based geopolymer mortars specimens.

Comparison of the Mechanical Properties and Crack Expansion Mechanism of Different Content and Shapes of Brass-Coated Steel Fiber-Reinforced Ultra-High-Performance Concrete

Steel fiber-reinforced ultra-high-performance concrete (UHPC) is becoming an important type of concrete reinforcement. After mixing with the reinforced steel fibers, the UHPC has perfect flex resistance, shear strength, crack resistance, shock resistance, and anti-seepage. In this study, the influence of straight, corrugated, and hooked brass-coated steel fibers (BCSFs) on the microstructure, mechanical properties, and crack expansion mechanism of ultra-high-performance concrete (UHPC) with varying content of 1-6 wt.% under different curing times were investigated. Field emission scanning electron microscopy and energy dispersive X-ray spectrometry were employed to characterize the microstructure of the BCSF-reinforced UHPC mix specimens. X-ray computed tomography was employed to determine the porosity of the BCSF-reinforced UHPC mix specimens. The obtained results indicate the flexural strength and compressive strength of BCSF-reinforced UHPC mix specimens are enhanced, along with increasing the content of BCSFs reinforcement with different shapes (straight, corrugated, and hooked). The embedded BCSFs play a major role in the adhesive property and stress transfer of the BCSFs-UHPC matrix interface. Different from many studies, the flexural strength of mix UHPC with straight BCSFs is higher than those with corrugated and hooked BCSFs. However, the compressive strength of UHPC with corrugated BCSFs is higher than those with straight and hooked BCSFs. The flexural strength of mix UHPC with 6 wt.% straight BCSFs at 28 days reaches the maximum value of 26.2 MPa, and the compressive strength of UHPC with 6 wt.% corrugated BCSFs at 28 days reaches the maximum value of 142.3 MPa. With the increase in straight BCSF content from 1 wt.% to 6 wt.%, the porosity in mix UHPC reduces gradually from 18.4% to 8.3%. The length of average crack spacing is dependent on the straight BCSF content. With the increase in straight BCSF content from 1 wt.% to 6 wt.%, the average crack length reduces gradually from 34.2 mm to 12.1 mm, and the average crack width reduces gradually from 0.78 mm to less than 0.1 mm. During crack extension, part of the energy in the UHPC mixture specimen with the 6 wt.% BCSF content flows into the crack tip region converted into the work dissipated during the bridging process. The crack propagation resistance of the UHPC mixture with straight BCSFs was improved compared with those with corrugated and hooked BCSFs. The bond strength between the BCSFs and UHPC matrix was enhanced by using vibrational mixing, and the brass film coated on the BCSFs contributes to increase the flexural and compressive strength of the UHPC mixture.

Role of Zinc Oxide in the Compounding Formulation on the Growth of Nonstoichiometric Copper Sulfide Nanostructures at the Brass-Rubber Interface.

Tire technology has evolved substantially by the introduction of brass-coated steel cords (BCSCs) in radial tires. The durability of radial tires is dependent on the integrity of the brass–rubber interface composed predominantly of nonstoichiometric copper sulfide (Cu2–xS, where x = 1 to 2) nanostructures whose morphology and characteristics are dependent upon the crucial rubber additive, ZnO. Its higher concentration impacts environmental sustainability, while at lower levels, there is insufficient bonding between steel and the rubber thus affecting tire’s safety. This brings in the need for an optimum ZnO concentration to be used in radial tires and is thus the theme of the present work. The changes in the properties of interfacial nanostructures such as morphology, thickness, crystallinity, and chemical composition were studied at various ZnO concentrations. We adopted our previously reported methodology, the “brass mesh experiment”, to investigate the thickness of nanostructures at varied ZnO concentrations using transmission electron microscopy (TEM). Significant results were obtained from field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman imaging and X-ray photoelectron spectroscopy (XPS). In conjunction with a more practical experimental technique, namely the measurement of pull-out force (POF), it has been concluded that 9 parts per hundred rubber (PHR) ZnO is essential for the optimum growth of nanostructures and is considered to be the optimum for the composition studied. We believe that the scientific approach outlined in the manuscript would help the tire- and the material science communities to widen the knowledge of understanding sustainability in tire industries. It is estimated that the optimization presented here can save $400–450 million for the tire industry and 2.4 million tons of ZnO per year.

Bonding Behaviour of Steel Fibres in UHPFRC Based on Alkali-Activated Slag.

The mechanical performance of fibre-reinforced ultra-high-performance concrete based on alkali-activated slag was investigated, concentrating on the use of steel fibres. The flexural strength is slightly higher compared to the UHPC based on Ordinary Portland Cement (OPC) as the binder. Correlating the flexural strength test with multiple fibre-pullout tests, an increase in the bonding behaviour at the interfacial-transition zone of the AAM-UHPC was found compared to the OPC-UHPC. Microstructural investigations on the fibres after storage in an artificial pore solution and a potassium waterglass indicated a dissolution of the metallic surface. This occurred more strongly with the potassium waterglass, which was used as an activator solution in the case of the AAM-UHPC. From this, it can be assumed that the stronger bond results from this initial etching for steel fibres in the AAM-UHPC compared to the OPC-UHPC. The difference in the bond strength of both fibre types, the brass-coated steel fibres and the stainless-steel fibres, was rather low for the AAM-UHPC compared to the OPC-UHPC.

Pullout damage analysis of steel fiber with various inclination angles and interface states in UHPC through acoustic emission and microscopic observation

The bond properties of fiber-matrix interfaces can significantly affect the tensile performance of ultrahigh-performance concrete (UHPC), and the fiber pullout test is the most direct method to study these properties. In this paper, in combination with acoustic emission (AE) and microscopic observation, an appropriate test method was set up to study the pullout damage process of brass-coated steel fibers, especially in the initial stage (slip of 0–0.2 mm) involving fiber debonding and matrix spalling. In addition to the fiber inclination and the loading rates, the potential corrosion, abrasion, and curvature of fibers in the actual casting process were considered in the tests. Moreover, a force function was introduced to an existing analytical model to describe the force provided by fiber end deformation, and the bond stress of aligned fibers was analyzed with the modified model. The test results indicate that: fiber with rougher surfaces has higher bond strength but a lower bond modulus and more severe damage on the fiber-matrix interface; the fiber curvature can both enhance the bond strength and alleviate the damage caused by snubbing effect; the corrosion product can rough the fiber surface and weaken the force provided by fiber end deformation. It is also found that the AE cumulative signal strength (CSS) is a helpful index to evaluate the matrix damage caused by snubbing effect in inclined fibers.

Effect of fiber type and content on the mechanical properties and shrinkage characteristics of alkali‐activated kaolin

AbstractAn experimental study was carried out to evaluate the effect of several fibers on the mechanical properties, drying shrinkage, and microstructural characteristics of alkali‐activated kaolin binders. Four different types of fibers were evaluated in this study: polypropylene (PP) fiber, discontinuous structural synthetic (DSS) fiber, brass‐coated steel (BCS) fiber, and hooked steel (HS) fiber. The fibers were added to the alkali‐activated kaolin at a volume fraction of 0%, 0.5%, 1%, and 1.5%. The experimental results revealed that the compressive strength of alkali‐activated binder increased by about 60% when 1% of PP fiber is added, whereas the addition of HS fiber substantially enhanced the flexural strength (more than 200% when 1.5% fiber volume content is added). BCS and HS fibers were found to more effective compared to PP and DSS fibers in maintaining the binder integrity prior to high temperatures exposure. All fiber‐reinforced alkali‐activated composites yielded lower drying shrinkage (≤450 microstrains), where HS fiber was found to effectively prevent the shrinkage of the binder (≤60 microstrains). The microstructural investigation revealed good interfacial bonding between the alkali‐activated binder and the fibers.

Evaluation comparison of wave amount measurement results in brass-plated tire steel cord using RMSE and cosine similarity

<span lang="IN">In the production process, quality checking is very important, one of which is on the wire. In the process of making brass-coated steel tire straps sometimes produce quality goods not in accordance with the desired standard values. Checks that are carried out manually have low efficiency and quite high errors occur. So it is necessary to check by measuring the wavelength on the brass plated steel cord automatically. In this study, used 3 automatic measurement methods using 2 evaluations, namely RMSE and Cosine Similarity. The results showed the best measurement using RMSE with method 2. Whereas the worst method uses RMSE with method 1. The smallest RMSE value is 0.0098 and the largest RMSE is 0.0966. The lowest Cosine Similarity value is 0.1253, while the highest Cosine Similarity value is 0.2079.</span>

The effect of trio-fiber reinforcement on the properties of self-compacting fly ash concrete

Present study is aimed to investigate the mechanical and durability properties of trio-fiber self-compacting concrete (TFSCC) containing fly ash. Self-compacting concrete was produced in all experiments with a water binder ratio of 0.38%, steel fiber and brass-coated steel fiber rate of 2% and polypropylene fiber added in the rates of 0%, 0.05% and 0.1%. In the scope of the study, fresh concrete experiments were performed such as flow diameter and flow time to 50 cm diameter (t50), V-funnel flow time, L-box and J-ring. Hardened concrete tests were performed for mechanical properties such as compressive strength, tensile splitting strength, flexural strength, ultrasonic pulse velocity. Additional tests were conducted in terms of durability e.g. to determine the impact of high temperature (ultrasonic pulse velocity and compressive strength at 200, 400 and 600 °C), freeze–thaw test (weight loss, ultrasonic pulse velocity and compressive strength in 50, 100 and 300 cycles) and high–pressure capillarity tests. Microstructures of the concrete samples were examined by taking their SEM images. It was observed that as the rates of steel and polypropylene fibers increased in the mixes, the flow diameter decreased while it increased with the increasing rates of fly ash and brass coated steel fiber. It was also seen that as the rate of polypropylene fiber in the mixes increased, losses in resistance to freeze–thaw impact decreased. It was determined when considered micrographs taken using SEM that fly ash provides favorable effects on concrete like forming full compactness at micro level and CSHs by binding calcium hydroxide and resulting in adherence on interfaces.

Identification of the Corrosion Mechanism of Brass-Coated Steel Wires in Cords Assembly

The corrosion behavior of brass-coated steel wire in cord assembly is discussed in this article. Experiments were performed on wires with different diameters and a cord composed of 19 wires. The open-circuit potential was recorded in a stagnant, aerated and neutral sulfate solution. Results showed a preferential initiation of the corrosion on morphological defects induced by the drawing. Moreover, the galvanic coupling between the brass layer and the steel led to the preferential dissolution of iron. For the cords, a crevice-like mechanism was identified. Inside the wire assembly, local acidification takes place because of the hydroxylation of iron ions. Lepidocrocite (γ-FeOOH) was detected by micro-Raman spectroscopy suggesting a pH of about 5 in the confined environment. At the external surface of the cord, both γ-FeOOH and Fe3O4 were identified. Their presence was attributed to the local variation of pH induced by a repartition of cathodic and anodic areas. Based on these results, a general scheme was proposed to illustrate the mechanism of corrosion of the cords.

Mechanical properties of reactive powder concrete with ultra-short brass-coated steel fibres

The mechanical properties (compressive strength, quasi-static fracture behaviour under three-piont loading, and fracture energy) of reactive powder concrete with ultra-short brass-coated steel fibres (12, 6 and 3 mm) were investigated. Steel fibre length had a small impact on the compressive strength of reactive powder concrete. Nevertheless, the quasi-static fracture behaviour showed clearly lower load-carrying capacity after the peak load with decreasing steel fibre length, indicating the decreased toughness of reactive powder concrete with shorter steel fibres. Obtained by integrating the area under the load–deflection curve, the fracture energy sharply decreased about 50% when reducing steel fibre length from 12 to 3 mm. These results will give guidance for the fabrication and study of reactive powder concrete–metal sandwich protective structures with high ballistic performance, low weight and low fabrication cost in the future.

RUBBER–BRASS ADHESION LAYER ANALYSIS USING THE OLEFIN-METATHESIS METHOD

ABSTRACT The investigation of the adhesion layer between rubber and brass-coated steel wires is a challenging task due to its strong bonding. We explore the possibilities of olefin-metathesis as a method to degrade the cross-linked rubber network without destroying the adhesion layer. Using a ruthenium catalyst and 1-octene as a co-reactant, different types of rubber—natural rubber, acrylonitrile–butadiene rubber, and styrene–butadiene rubber—can be degraded into soluble fragments. The uncovered adhesion layers can be subsequently analyzed with common analytical methods such as optical microscopy, focusvariation microscopy, and scanning electron microscopy. The revealed surface structures are discussed considering the observed pull-out forces. In a second series, the influence of common additives—cobalt salt, silica, and a resin system—on the metathesis reaction is investigated.

Development of cement-based strain sensor for health monitoring of ultra high strength concrete

In this research a cement-based strain sensor (CBSS) with high strength and self-sensing ability is developed, and the use of the high strength CBSS for structural health monitoring of ultra high strength concrete (UHSC) columns is evaluated. Results show that the CBSS with 0.5% brass-coated steel fibers has high compressive strength of >120MPa. Its piezoresistivity shows little noise, indicating the resistance of the CBSS varies smoothly with the strain. After oven-drying, the repeatability and sensitivity of the piezoresistivity has greatly improved. When the CBSS is embedded in a UHSC column, damage monitoring of the UHSC column can be performed by means of increasing irreversible change in the resistance of the embedded CBSS. The embedded CBSS can sense strain as well as stress of the UHSC column up to a stress of 154MPa. The piezoresistive behavior of the embedded CBSS undergoes three phases during the monotonic loading, and they are high sensitive, linear phase; medium sensitive, nonlinear phase; low sensitive, linear phase with the increase in load.

Study of Cu–Zn–Co ternary alloy-coated steel cord in cobalt-free skim compound

In this study, it is shown that the rate of bond degradation due to ageing in hot & humid conditions can be significantly reduced by the use of a Cu–Zn–Co ternary alloy coating, compared to current compounds and normal brass-coated steel cord. To better understand the adhesion mechanism, X-ray photoelectron spectroscopy is used to investigate the adhesion interface upon hot and humid ageing. In addition, the effect of removal of cobalt salts from compound on static and dynamic rubber compound properties is studied: it is found that this leads to improved heat ageing resistance, slower crack growth rate and less hysteresis. Hence, the new Cu–Zn–Co ternary alloy coating for steel cord allows cobalt salts to be removed from tires, which makes tires more durable and eco-friendly.

Mitigation of Detrimental Effects of Alkali-Silica Reaction in Cement-Based Composites by Combination of Steel Microfibers and Ground-Granulated Blast-Furnace Slag

The effect of combining brass-coated steel microfiber and ground-granulated blast-furnace slag (GGBS) on the mitigation of deleterious expansion due to alkali-silica reaction (ASR) was investigated in this research. A potentially reactive basaltic aggregate was chosen as a reactive material. Two series of specimens containing different amounts of microfiber were prepared. One of them was cured in 1 M NaOH solution at 80°C to obtain a similar maturity; the other series was cured in 80°C water up to 120 days. ASR expansion, strength development, and toughness properties were observed for 120 days in NaOH solution and the results were compared with specimens kept in water. Test results indicate that the combination of GGBS and steel fibers reduced ASR expansion significantly. Furthermore, the combination was very effective at preventing the mechanical property loss due to ASR, such as flexural strength, compressive strength, and toughness. Microstructural investigations revealed that the reaction products had a different morphology (e.g., fibrous, network appearance) when the specimens were kept in NaOH solution.

A novel promoter for enhancing adhesion between natural rubber and brass-plated steel cords

In this study, a conventional manobond promoter as well as a newly synthesized kaolin modified resin (KMR) were applied in various concentrations into rubber mixes to investigate their performance in improving the adhesion between NR and brass-coated steel cords. Two types of steel cords were used to prepare T-shape samples for pullout test. The samples were aged under aerobic aging conditions or exposed to ionizing radiation and the adhesion force was examined. The analysis of variance (ANOVA) was used to obtain a general understanding of the impact of changing various parameters and their inter-relationships on the static adhesion between NR and brass-coated steel cords. The results revealed that the use of the prepared promoter has significantly resulted in the clear stability of the cure rate index of the NR mixes. Also, the presence of KMR in the rubber mix enhances the mechanical properties of the rubber to a great extent. The results showed also that the NR mixes with KMR promoter have higher adhesion levels than those of the manobond promoter.

Methodology for Measuring Trace Metal Surface Contamination on Pv Silicon Substrates

The production of high efficiency PV cells requires a strict control on metal contamination levels. Metals like Cu and Fe are well known to cause lifetime degradation in silicon. Analytical methodologies for determination of surface metal contamination have been well established for mirror polished, also referred to as chemical mechanical polished (CMP) silicon substrates [1]. It will be explained why these methods cannot be merely applied to photovoltaic (PV) wafers because of the large roughness and specific topography of the surface. Here we extend and adapt these analytical methodologies for surface metal contamination analysis on PV substrates also referred to as PV wafers. We demonstrate how vapour phase decomposition droplet collection (VPD-DC) in combination with total reflection X-ray fluorescence spectroscopy (TXRF) or inductively coupled plasma mass spectrometry (ICP-MS) has been modified to accommodate analysis on a non-polished PV silicon wafer surface. In addition we demonstrate how metal contamination on as-cut PV wafers has been determined by liquid surface etching (LSE), i.e. an oxidizing and slow etching solution used to dissolve metal contaminants, followed by TXRF analysis. Measurements of as-cut wafers shows the presence of Fe, Cu and Zn in very high concentrations (up to more than 1x1013at/cm2), residuals of the brass-coated steel wires used during wire sawing [10].