Waste Steel Fibers Research Articles

Preventive Measures of Alkali–Silica Reaction in Concrete Buildings: Use of Hybrid Waste Coal Ash and Steel Wire Cut Fibers

The main cause of premature deterioration in concrete buildings is linked with the alkali–silica reaction (ASR) owing to the use of reactive aggregates and severe exposure conditions. This research aimed to explore the mitigation of ASR in concrete buildings using waste coal ash (CA) and steel fibers cut from long wire. CA and SF were acquired from a local market. The studied dosages of CA were 10%, 20%, 30% and 40% by cement weight and steel fibers were added at 0.5% and 1% of the total volume of the mixture. Specimens were cast and immersed in a 1N NaOH solution at 80 °C for 90 days as per ASTM C1260 guidelines. The compressive and flexural strengths of the control mixture without CA and the mixture with 10% of CA had a comparable behavior. A decrease in the compressive and flexural strengths was observed for higher dosages of CA (30% and 40%). Specimens incorporating 30% of CA showed a compressive strength of 24 MPa at 56 days compared to that of 33 MPa for the identical control specimen without CA. This strength decrease was due to the porous nature of the used CA and was compensated for by the incorporation of steel fibers. Specimens with 1% of steel fibers exhibited higher strength properties compared to those with 0.5% of steel fibers for all the tested dosages of CA. The control specimens without CA and steel fibers showed expansions higher than 0.10% and 0.20% at 14 and 28 days, respectively, demonstrating their reactive behavior. The hybrid incorporation of CA and steel fibers decreased the ASR expansion. The mortar bar specimen incorporating 10% of CA and 1% of steel fibers showed an expansion of 0.168% at 28 days compared to that of 0.321% for the control specimen without CA and steel fibers. A decrease in the compressive and flexural strengths was observed for the specimen placed in ASR exposure conditions compared to identical specimens placed in normal water. However, specimens incorporating CA and steel fibers showed relatively fewer effects under the ASR exposure conditions. The control specimens without CA and steel fibers also showed micro-cracking due to ASR exposure, as observed through scanning electron microscopy. This study will assist practitioners to construct a sustainable building using locally available waste materials with the additional advantage of mitigating the ASR-related damages.

Experimental investigation on the mechanical properties and damage evolution of steel-fiber-reinforced crumb rubber concrete with porcelain tile waste

The utility of crumb rubber concrete (CRC), a green concrete containing waste tire rubber particles as partial replacement for natural fine aggregate, is limited by its lack of strength. It is found that the addition of steel fibers is a solution to the limitation. This study proposes using porcelain waste coarse aggregates and steel fibers to improve the cubic compressive strength and flexural strength of CRC and avoid the pollution caused by porcelain waste. Porcelain waste was incorporated at replacement percentages of 25%, 50% and 100% by volume. Steel fibers were incorporated at volume fractions of 1% and 1.25%. The cubic compressive strength and flexural strength of CRC, steel-fiber-reinforced CRC (SFRRC) and SFRRC with porcelain waste were then tested. The results obtained show that the strengths of CRC are greatly improved by the incorporation of steel fibers and 25% porcelain waste. With the increase in porcelain waste content, the strengths of SFRRC containing porcelain waste decrease. Scanning electron microscopy was then conducted and the findings show that the strengths decrease at high porcelain waste content due to the weak bond between the glaze of porcelain waste and the cement matrix. The fracture processes of three types of concrete under four-point bending were monitored by using acoustic emission (AE) technique. Based on the AE data, the parametric analyses, including cumulative hits analysis, b-value analysis and RA-AF analysis, were performed for three types of concrete and presented characteristics of damage evolution of them. This paper provides information about the mechanical properties and fracture process of a new type of green concrete that can be used in bending members of concrete structures.

Fresh and hardened state properties of waste tire fiber and steel fiber reinforced concrete

Concrete is a widely used construction material but is known that several properties of plain cement concrete can be improved by the addition of certain fibers in certain percentages and this procedure-oriented substance is known as Fiber-reinforced concrete (FRC). And one of such most commonly used fibers is steel fiber, which is known to improve the mechanical properties of concrete. The usage of the waste tire as fibers would reduce the environmental degradation and it is also proven that it too can improve the properties of PCC. This paper investigates certain fresh and hardened state properties namely workability, compressive strength, and abrasion resistance of concrete reinforced with both steel and tire fibers in various proportions of the volume of concrete at 0%, 0.25%, 0.75%, 1%, and the results were analyzed.

Experimental investigation on mechanical properties of HSSCC containing waste steel fibers obtained from end-of-life tires

In this study, use of end-of-life tires (ELTs) in self-consolidating concretes (SCC), which enable higher rates of fiber use than conventional concrete due to its superior flow properties, for the elimination of the environmental negative impacts and recycling of them were aimed. Besides, it is aimed to investigate the behavior of waste steel wires with different aspect ratio obtained from different types of tires, contrary to what is mostly researched in the literature. Therefore, bead, cord and base wires, obtained from tires, were used in high-strength self-consolidating concrete (HSSCC) production as fiber reinforcement. Fresh and hardened state properties of the waste wire-reinforced (1-2-3%) samples of different sizes that were produced, were compared with industrial steel-reinforced and non-fibrous samples. In this regard, slump flow and T50 durations were determined, compression and bending tests were performed. Significant improvements in the mechanical properties of conventional concretes were observed with the use of waste wire. Using the optimum ratio of waste wire, an increase of approximately 102% in flexural strength and 14% in compressive strength was observed compared to the reference specimen. Aspect ratio was recognized as one of the most effective factor on optimum fiber content. Moreover, experimental results were analyzed with "paired sample t-test", and it was seen that there were no considerable differences in the mechanical properties of the samples in which industrial fiber and waste-wire had been used. Besides, cost analysis was carried out to assess the economic benefits of the use of waste tire wires in the concrete industry.

A worldwide development in the accumulation of waste tires and its utilization in concrete as a sustainable construction material: A review

The worldwide enhancement in the accumulation of waste tires and associated upcoming environmental and social concerns are becoming the primary intimidations. Waste tires are considered an undervalued resource globally, and their sheer volume is used to be disposed of in landfills, a primary concern. Instead of disposing of waste materials after recycling, the utilization can have a considerable impact. The trend of extracting steel fibers from waste tires is emerging nowadays. Incorporating waste recycled tire steel (WRTS) fibers, obtained from waste tires in concrete is a potential profit-gaining engineering application. But there are still some challenges, like WRTS fibers' suitable volumetric content and length selection, which need to be addressed by having in-depth exploration. Research has been conducted on incorporating reused waste materials in cementitious composites. Concrete ingredients are meant to provide strength, but adding reused waste materials to concrete helps reduce environmental pollution and make it sustainable and economical. In previous literature, the impact of such waste fibers on the key properties of concrete, such as ultrasonic pulse velocity, compressive, splitting-tensile and flexural strengths, energy absorption, modulus of elasticity, toughness, and ductility, were investigated. Adding WRTS fibers to concrete can enhance its compressive strength by more than 10 % and flexural strength by more than 50 %. This paper aims to review the application of WRTS fiber-reinforced concrete to identify the research gap for researchers in this direction. The available research outcomes and the recycling process of WRTS fibers are summarized and discussed. It is concluded that incorporating WRTS fibers in concrete would result in sustainable development by providing economical and environment-friendly construction materials with improved mechanical properties.

EFFECTS OF WASTE STEEL FIBRES ON THE MECHANICAL PROPERTIES OF MODIFIED SELF COMPACTING CONCRETE

Waste Steel Fibre (WSF) and Rice Husk Ash (RHA) were used in the production of Self Compacting Concrete (SCC). Seven variants of SCC mixes were prepared. The rheological and mechanical properties (Compressive Strength (CS) and Split Tensile Strength (STS)) of the SCC produced were examined. The results showed that the blocking ratio varied marginally while other fresh properties of the SCC with WSF compared favourably to the standard. The CS of the hardened control samples after 56 days of curing was 36.18 N/mm2 while the CS of SCC with 15 % of RHA and 0.0 %-0.5 % of WSF, ranged from 37.04 - 43.64 N/mm2 with the maximum CS at 0.4 % WSF addition. Similarly, the STS of SCC at 56 days improved with an increase in WSF content up to 0.4 % and decreased with further addition of WSF. The inclusion of WSF at the optimum level of 0.4 % addition had a better influence on the tensile strength of SCC thereby increasing the ratio of STS to CS.

Sustainable High-Performance Concrete Reinforced with Hybrid Steel Waste Fibers

This research aims to study the benefit of using fibers made from waste materials in concrete and evaluate the ability to use these fibers as a substitute for commercial fibers. Different aspect ratios of alternative fibers formed from cut steel tied wire waste were utilized. This material is selected because of its low price and wide availability. Two concrete mixes with 15% waste crushed clay brick coarse aggregate reinforced with different volume fractions of 1.0 and 1.5% and an aspect ratio of 40 were prepared. Also, three concrete mixes reinforced with a hybrid aspect ratio of 40 and 65 of tied wire waste steel fibers (TWWSF) with different volume fractions of 1.0% and 1.5% were prepared. The compressive, splitting tensile, flexural strengths, and ultrasonic pulse velocity (UPV) of all prepared concrete mixes were tested. The results illustrate that the inclusion of tied wire waste steel fibers significantly enhances the strength of concrete with 15% waste crushed clay brick coarse aggregate, and high-performance concrete with compressive strength of up to 85 MPa can be produced. The enhancement in compressive, splitting, and flexural strengths were 29%, 42.8%, and 38%, respectively, for concrete reinforced with a fiber aspect ratio of 40 and volume fraction of 1.5%. In comparison, for the same volume fraction, the percentage was 22%, 48%, and 44%, respectively, for equal content of hybrid aspect ratio of 40 and 65.

Experimental study on basic mechanical properties of recycled steel fiber reinforced concrete

Abstract Recycled steel fiber (RSF)-reinforced concrete is not only an innovative research trend in the field of civil engineering materials, but also a new type of civil engineering composites under the trend of low-carbon development. This article deals with the experimental study of applying waste steel fibers to form recycled steel fiber concrete (RSFC). The main materials in this study are RSF, coarse and fine aggregate, fly ash, silica fume, and water reducer agent formed by machining surplus materials as the main materials. Three types of concrete were prepared. They were normal concrete, primary steel fiber concrete (PSFC), and RSFC with six different volume contents. The slump and air content of the three types of concrete are compared and analyzed. Then, the effects of the volume content of RSF on the cube compressive strength, splitting tensile strength, flexural strength, and axial compressive strength of RSFC are studied. Finally, the toughness of RSFC is discussed. The test results show that with the increase in the volume content of RSF, the slump of RSFC is significantly reduced, the compressive strength, tensile strength, and flexural strength are enhanced, the increase in tensile strength and flexural strength is significantly higher than the cube compressive strength, and the RSF has an obvious inhibitory effect on the development of concrete cracks which can obviously enhance the ductility and toughness of the concrete.

Progressive collapse behavior of steel fiber-reinforced rubberized concrete frames

The efficiency of combining fine aggregate's (sand) partial replacements with waste crumb rubber (CR) and steel fiber (SF) has been investigated in this paper. The study aims to enhance the RC frame's deformability, as well as its structural ductility to achieve progressive collapse resistance. To this end, a total of four RC frames' behavior at one-third scale under a situation of a middle-column removal was experimentally tested. Two frames were made of 0% CR and SF. Another two frames were made by incorporating CR at 20% by volume for the sand replacement and 0.5% SF fraction volume. The findings of the study reported an enhanced structural ductility, which was stimulated by incorporating CR and SF in normal concrete. The tested steel fiber-reinforced rubberized concrete frames, however, showed further deflection by 29.5% compared with the conventional frames.

Preparation of low-cost reactive powder concrete using waste steel fibres recycled from scrap tires

The application of reactive powder concrete (RPC) was not wide. One of the main problems was that copper-coated steel fibres (CSF) were expensive. In order to prepare low-cost RPC and resource utilisation of waste steel fibres recycled from scrap tires (WSF), this paper investigated the fluidity and strength of RPC containing WSF. The results indicated that the fluidity of RPC containing WSF was worse than that of RPC containing CSF. But there was not much difference in the strength of two kinds of RPC. In order to optimise performance of RPC containing WSF, the influence of mineral admixtures on the fluidity and strength of RPC was discussed. The results indicated that the optimum silica fume dosage was 20%, and the optimum fly ash and limestone powder dosages were 5%, respectively. Through this study, it was completely feasible to prepare RPC containing WSF. The use of WSF can reduce the cost of RPC.

Coupled effect of waste tire rubber and steel fibers on the mechanical properties of concrete

Abstract Studies in the literature indicate that while tire crumb rubber can be added to concrete to replace some natural aggregates, steel fibers need to be introduced to overcome the compromise in the mechanical properties of concrete, especially compressive and tensile strength, that would be caused due to the addition of tire crumb rubber exclusively. In the present study, a minimum content of steel fibers has been added to mitigate the negative impact of addition of tire rubber fibers on the mechanical properties of concrete. The tire rubber fibers content was varied from 1% to 3% by volume whereas steel fibers were added from 0.1% to 0.3% by volume only. In this way, the effectiveness of hybridized concrete using tire rubber and steel fibers was evaluated based on its mechanical properties. The results revealed that inclusion of steel fibers overcame the reduction in strength and toughness of concrete to which tire rubber fibers have been added. Concrete with 2% tire rubber fibers and 0.2% steel fibers showed better mechanical performance in terms of compressive strength (10%), split tensile (14.7%), flexural strength (6.6%), and flexural toughness indices ( T 150 D = 46 % T_{150}^D = 46\% , f 150 D = 45 % f_{150}^D = 45\% ) as compared to the concrete with only 3% tire rubber fibers.

The Combined Effect of Waste Iron Powder and Steel Fiber on the Fresh and Hardened Properties of Geopolymer Mortars Exposed to High Temperatures

The Combined Effect of Waste Iron Powder and Steel Fiber on the Fresh and Hardened Properties of Geopolymer Mortars Exposed to High Temperatures

Impact performance of rubber reinforced concrete with waste steel fibres

This study introduces cementitious composite with rubber granulate and waste steel fibres as a new material for construction industry with an enhanced energy absorption capability and impact toughness. Detailed research on physico-mechanical properties of high-performance concrete with waste steel fibres and partial replacement of the aggregates by rubber granulate was performed, with emphasis on impact energy absorption potential. Different aggregate replacement ratios (0–30% wt.) and fibre amount (0–3% wt.) were investigated. The influence of rubber sizes, rubber content and steel fibre content on the mechanical parameters of the rubberized concrete at both quasistatic and dynamic loads was evaluated and discussed. With increasing amount of rubber granulate, the concrete suffered from reduction of its mechanical parameters – compressive and flexural strength, however the energy dissipation capability showed rising trend. This study demonstrated the potential of rubberized concrete with waste steel fibres for use in structures with higher impact resistance requirements.

Review of materials used in Low density concrete as Eco-friendly

Lightweight concrete is the most popular type in constructional activities to get low density for the concrete just as to diminish the extra weight of the structure. There are different types of lightweight concrete based on the type of lightweight material used. As considering eco-friendly materials like waste tires, waste steel fibres, plastic waste, agricultural waste, waste glass can be utilized in concrete by replacing coarse aggregate and fine aggregate. Lightweight concrete is preferable in constructional activities because of its low warm conductivity and improves fire resistance. In general, lightweight concrete ranges from 1440 to 1840 kg/m3. The main aim is to conclude the high-performance lightweight concrete by using a different type of materials in the same way to achieve low density for the concrete. By this study, we understand that high performance can be achieved by adding steel fibres to improve ductility and for low-density waste tire rubber by partial replacement in coarse aggregate and to improve durability by adding bacillus subtilis JC3 crack formation can be reduced.

Evaluation of post-fire pull-out behavior of steel rebars in high-strength concrete containing waste PET and steel fibers: Experimental and theoretical study

The present research addressed the post-fire bond performance between high-strength concrete incorporating waste polyethylene terephthalate (WPET) and steel reinforcement; a subject that had not been previously addressed. Further, the impact of incorporating steel fiber, as a commonly used material, into the mixture on the bond improvement was assessed. To this end, the content of WPET substituting for the fine aggregate by volume (0, 5, and 10%), volume fraction of steel fibers (0, 0.5, and 1%), applied temperature (25, 200, 400, and 600 °C) were considered as variables in a total of 108 samples that were produced. Afterward, the samples were subjected to the pullout test to examine different parameters. These parameters included the bond behavior, failure mode, bond stress-slip response, and bond strength-compressive strength behavior. Based on the results, with the incorporation of 5 and 10% volume content of WPET replacing fine particles, the bond strength declined by 4 and 26%, respectively, and as the temperature was raised, this reducing effect increased. Furthermore, the presence of steel fiber had a positive impact in the samples with the splitting failure mode, while it had a negligible or sometimes even negative impact in the samples with the pull-out failing mode. Lastly, multivariate prediction models were proposed for the bond behavior and bond-slip response as a function of the concrete compressive strength, WPET content, content of steel fiber, and the target temperature. Afterward, a comparison was made between the empirical results and the predictions of models developed by other researchers and the fib Model Code 2010 and ACI 408-12 codes.

Impact Resistance of Concrete with Recycled Steel Fibers and Crumb Rubber.(Dept.C)

Concrete with waste steel fibers and crumb rubber (WSFCR) was primarily created using components that are extracted from the scrap tires recycling process. Crumb rubber particles of size (1- 4) mm and relative density 1.0 gm/cm3 were included as a partial replacement (10% by volume) of natural sand. Recycled or waste steel fibers were used in four percentages from the total mass of the concrete (0.5%, 1.0%, 1.5%, and 2.0%). The efficiency of WSFCR has primarily been studied to evaluate its performance against impact loads, compared to the performance of traditional concrete (CR 0), rubber concrete (CR 10%), and rubber concrete reinforced with industrial steel fibers (ISFCR). Also, the influence of recycled steel fibers on the different strengths of the rubberized concrete was presented. A total number of eleven slabs (1000×1000×100 mm) were subjected to 10.738 Kg cylindrical steel weight falling from a 1.5 m distance concerning the number of blows at the first crack formation and complete failure. Both WSFCR and ISFCR showed outstanding performance under impact loads compared to CR0 and CR 10% control mixtures. Although ISFCR resulted in a higher impact energy resistance than WSFCR, which showed convergent results and a similar crack pattern; therefore, it is a strong candidate as a low-cost alternative to industrial steel fibers.

Laboratory Investigation and Numerical Modelling of Concrete Reinforced with Recycled Steel Fibers.

In the last decades, fiber reinforced concrete have emerged as the possible key to revolutionize civil engineering. Among different types of fibers employed in concrete technology to date, the application of recycled steel fibers produced from end-of-life car tires appears to be a viable approach towards environmentally friendly construction. In this study, we demonstrate the laboratory research and numerical analysis of concrete reinforced with waste steel fibers recovered during the recycling process of end-of-life car tires. Concrete mixes with the following fiber contents: 0.5%, 0.75%, 1.0%, 1.25%, and 1.5% per volume were prepared and then tested in three-point bending conditions. The laboratory investigation revealed highly boosted properties of concrete under flexure. We further performed the finite element method (FEM) analysis of 2D models using Atena software in order to develop a material model allowing the numerical modelling of recycled steel fibers reinforced concrete (RSFRC) behavior. The parameters of RSFRC material model have been modified using the inverse analysis until matching the experimental performance of the material. The results, being in good agreement with the laboratory investigation, have indicated a high potential of RSFRC for real scale construction applications.

Mechanical Performance of Recycled Aggregate Concrete Containing Lathe Waste Steel Fibre

The increasing demand, diminishing supplies, and growing pressure on natural resources have necessitated recycling and reusing waste. Several kinds of research have been done on the reuse and recycling of debris from building projects. Thus, with a view to the reuse of waste materials, the elimination of environmental contamination, the reduction of overhead costs of concrete, and the extension of the service life of concrete structures, this research aimed to study the feasibility of utilizing recycled concrete aggregate (RCA) with constant inclusion of waste steel fibre (LWSF) in concrete by evaluating its workability, compressive and splitting tensile strengths. A concrete mix ratio of 1:2:4 by weight of cement, sand, and granite was adopted with a water-cement ratio of 0.45. Five different concrete mixes were prepared in this study; one normal aggregate concrete (NAC) and four (4) other mixes with 25%, 50%, 75%, and 100% recycled aggregate content with a constant 1.5% addition of LWSF. The result of workability shows a reduction with an increase in the percentage replacement level. The recycled aggregate concrete (RAC) was characterized by lower compressive strength as compared with the NAC. When the replacement ratio increased from 25% to 50%, a significant reduction of about 14% and 30% were observed in the compressive strength at 7-days, but at 28-days slight increase in the compressive strength was observed. Also, a decrease in splitting tensile strength as the percentage replacement of crushed granite (CG) with RCA is increased was observed. Overall, the findings showed that the RAC-containing LWSF is environmentally sustainable and would significantly reduce the global greenhouse impact and building materials' overall quality.
 Keywords: Recycled concrete, lathe waste, steel fibre, compressive strength, tensile strength

Investigating flexural performance of waste tires steel fibers-reinforced cement-treated mixtures for sustainable composite pavements

In many parts of the world, the cement-treated base course material has been extensively used within composite pavements for enhancing the load-carrying capacity of pavements. However, its vulnerability to cracking under repetitive traffic loading, due to its brittle nature, significantly cuts off its lifespan and hence reducing the sustainability of composite pavements. To provide a solution to this problem, this study is aimed to investigate the flexural performance of cement-treated base (CTB) mixtures reinforced with the Waste Steel Fibers (WSF) extracted as a residual product from the scrap tires. The flexural performance is evaluated in terms of flexural fatigue and flexural strength. Moreover, the effect of steel fiber reinforcement on the dynamic modulus of the cement-treated base mixtures was also studied. The specimens for dynamic modulus were prepared by using a gyratory compactor to better simulate the traffic loading. Furthermore, the basic split tensile strength and unconfined compressive strength of WSF reinforced CTB mixtures were also studied. Lastly, important correlations were derived based on the results obtained in this study, to predict the flexural performance of CTB mixtures in terms of dynamic modulus and fatigue life by conducting basic split tensile strength tests and flexural strength tests. Based on the results, WSF reinforcement has noticeably enhanced tensile strength, dynamic modulus, flexural strength, and fatigue life of CTB mixtures. On the other hand, the variations in the compressive strength due to WSF reinforcement were trivial. Based on the results, the steel fibers content of 0.3% by volume of the wet compacted blend has shown more promising results than lower and higher WSF contents.

Combined influence of waste steel fibre and fly ash on rheological and mechanical performance of fibre-reinforced concrete

ABSTRACT This study aims to investigate the combined influence of varying concentration of waste steel fibre and fly ash on rheological and mechanical performance of fibre-reinforced concrete (FRC). Cement was substituted partially by fly ash at concentration of 5%, 10% and 20% by weight basis and waste steel fibre was incorporated as 1.5% and 3% in volume basis of concrete. Rheological tests of concrete, including slump, density, compacting factor, K-slump, and Kelly ball penetration were evaluated for the fresh state. Mechanical performances of concrete, including compressive, splitting tensile and flexural strength were determined at 7 and 28 days. Test results exhibited that fly ash enhanced the workability of all rheological tests; however, waste steel fibre reduced the workability and increased the density of fresh concrete. Substantial enhancement in compressive, splitting tensile and flexural strength was found for fly ash and waste steel FRC mixes than the control one. The optimum results of mechanical performance were achieved for mixture with concentration of 10% fly ash and 3% waste steel fibre among all mixes. Adding waste steel fibre with fly ash in concrete provided more pronounced mechanical performance at higher fibre concentration along with the minimisation of disposal problems and environmental damages.