Waste Carpet Fibers Research Articles

Investigating the Resistance Properties of Concrete Containing Waste Carpet Fibers

Investigating the Resistance Properties of Concrete Containing Waste Carpet Fibers

Production of waste carpet fiber-reinforced concrete as sustainable material

Waste materials evolve from various processes in industries that require efficient management for their disposal to ensure a cleaner environment. Disposing of solid waste, such as carpets, to sites has grown challenging since the development and management of sites are very costly. There is a dire need to manage such a vast amount of carpet waste efficiently. This study examines certain mechanical properties and durability characteristics of concrete incorporating discarded carpet threads and silica fume (SF). Initially, six different concrete mixes were produced, with 0.25%–1.0% waste carpet fibers by concrete volume and 10% SF by weight of cement. Then samples were tested for mechanical strength, i.e., compressive strength, tensile strength, and flexural strength. The durability characteristics, such as water absorption, rapid chloride penetration test, drying shrinkage, and freeze-thaw action, were also determined. The study shows that the abandoned carpet waste threads and SF (an industrial waste) in concrete significantly increase tensile and flexural strengths and various other durability characteristics. The further increase in fiber content resulted in a lowering of mechanical strengths and workability. Experimental results show the increase in tensile and flexural strengths of the concrete by waste carpet fibers (0.25%) and SF (10%) by 16.5% and 34%. SF and waste carpet fibers improve other durability characteristics, reducing freeze-thaw, drying shrinkage, and chloride ion permeability coefficient by up to 47%, 79%, and 50%. Additionally, using waste carpet fibers to ameliorate concrete properties instead of fresh fibers helps conserve natural resources. It leads to the conservation of resources, sustainability, recycling of wastes, and a circular economy.

Utilization of Waste Carpet Fiber to Produce Green Concrete; a Solution to Environmental Issues

Utilization of Waste Carpet Fiber to Produce Green Concrete; a Solution to Environmental Issues

Green high strength concrete containing recycled waste ceramic aggregates and waste carpet fibers: Mechanical, durability, and microstructural properties

This paper investigated the combined utilization of recycled waste ceramic aggregate (RWCA) and waste carpet fibers (WCFs) in high strength concrete (HSC). Concrete mixes containing different percentages of RWCA including 20%, 40%, 60% (by weight) as partial replacement of natural coarse aggregate (NCA) were prepared. To enhance the tensile and flexural strength of concrete, 1.0% (by volume) WCF was added to the mixes. The slump and density of the fresh concrete were evaluated, both of which demonstrated a decreasing trend with incorporation of RWCA and WCF. With regard to the hardened concrete, replacing 40% of NCA with RWCA led to the optimum mechanical properties and increased the compressive, splitting tensile, and flexural strengths by 13%, 15%, and 3%, respectively, over those of the control concrete after 28 days. Adding WCF to the same mix enhanced the tensile strength up to 21% over that of the control concrete and reduced the crack width. Regarding the durability properties, the optimum RWCA concrete reinforced with WCF showed 19% reduction in the 28-day electrical resistivity and 48% increase in water absorption. The scanning electron microscopy (SEM) images of WCF-reinforced concrete confirmed the bridging effect of WCF, which led to an enhancement in the tensile and flexural strengths of concrete. Based on the findings of the present study, it is possible to produce fiber-reinforced HSC with superior compressive and tensile strength by using specific dosages of RWCA.

Mechanical properties soil stabilized with nano calcium carbonate and reinforced with carpet waste fibers

Abstract One of the geotechnical engineering strategies for dealing with weak soils in a construction site is to alter their mechanical properties with the assistance of soil improvement techniques. The present study examined the effect of the addition of nano calcium carbonate (0, 0.4, 0.8 and 1.2% by weight of the soil) as a stabilizing nanoparticle and carpet waste fibers (0, 0.2, 0.4, and 0.6% by weight of the soil) as a reinforcement agent on the soil behavior. A total of 52 unconfined compressive strength tests, 52 ultrasonic pulse velocity tests, 12 unconsolidated undrained (UU) triaxial tests, and 8 Atterberg limit tests were performed to investigate the effect of fiber and nanoparticle contents and treatment time on the geotechnical properties of the clayey soil. The results showed that the addition of nanoparticles to the clayey soil reduces its liquid limit and increases its plastic limit. The best improvement in the soil strength, which was about 100%, was observed in the 42 days old sample with 1.2% nano calcium carbonate content. The combined use of fibers and nanoparticles also led to significant strength improvement. The addition of carpet waste fiber was found to increase the soil stiffness. Increasing the carpet waste fiber content above the 0.2% did not have much impact on the maximum strength, but significantly improved the residual strength. The addition of carpet waste fibers up to 0.2% increased the velocity of ultrasonic waves, but further increase in the fiber content resulted in reduced velocity. The paper provides a number of equations that express the relationship between the unconfined compressive strength and the ultrasonic pulse velocity for the clayey soils with different additive contents. The provided equations can be used to estimate the success of stabilization and strength improvement efforts based on the results of non-destructive ultrasonic pulse velocity test. The results of unconsolidated undrained triaxial tests showed that the used fibers alter the sample behavior in high strains. Also, the use of nano calcium carbonate and carpet waste fibers together almost doubled the undrained cohesion.

Impact behavior and microstructure of cement mortar incorporating waste carpet fibers after exposure to high temperatures

Abstract Adding waste carpet fibers to cement mortar as a cleaner production can improve the property of mortar. This study investigated the influence of different parts of industrial carpet waste on impact behavior and microstructure of mortar at elevated temperatures. Mortar containing normal polypropylene fibers, face fibers, backing fibers and hybrid fibers (face fibers and backing fibers) respectively as well as ordinary mortar were prepared and exposed to 20, 300 and 500 °C. The dynamic splitting tensile strength of these specimens was then measured at air pressures of 0.15, 0.2 and 0.25 MPa. In order to obtain the pore distribution and microstructure image, mercury intrusion porosimetry (MIP) and scanning electronic microscopy (SEM) were used. Finally, the fractal analysis was employed to further evaluate the impact of waste carpet fibers on microstructure of mortar. Results of this paper indicated that the incorporation of carpet face fibers is more feasible to improve impact behavior of mortar at elevated temperatures compared with adding ordinary polypropylene fibers. Moreover, the higher impact air pressure, or the higher temperatures, the more significantly reinforcing effects of face fibers is. Backing fibers and hybrid fibers have a negative role on the impact resistance whether heating or not. Pore distribution and microstructure of mortar incorporating face carpet fibers are better than other mortar, which is in agreement with the change of residual strength. Therefore, the addition of carpet face fibers to mortar does not only reduce environment pollution but also enhance the impact behavior of mortar after exposure to high temperatures.

RETRACTED: Enhanced performance for aggressive environments of green concrete composites reinforced with waste carpet fibers and palm oil fuel ash

Abstract World fiber production used in textile and carpet industries has been steadily increasing in the past few decades, now exceeding 70 million tons per year. About 50 tons of industrial waste polypropylene carpet fibers are sent to landfill in Malaysia annually. However, the landfill option is becoming increasingly impractical owing to growing landfill costs and the physical limitations on the number of landfill sites available. The need to recycle this waste is increasing owing to the lack of existing landfill spaces in many parts of the world, environmental concerns, and resource conservation. In this study, the performance of concrete composites comprising waste polypropylene (PP) carpet fiber and palm oil fuel ash (POFA) exposed to sulfate and acid after one year were investigated and obtained results were compared with those of water-cured specimens. Properties studied included visual inspection, mass, and strength measurements of hardened concrete. The particles morphology, as well as the effect of PP and POFA in the concrete-filler interfacial behavior, was investigated with scanning electron microscopy microstructural analysis. Six concrete mixes containing 0–1.25% fibers with a length of 20 mm were made for ordinary Portland cement (OPC). Further, six concrete mixes with the same fiber content were cast, where 20% POFA substituted OPC. It was found that the incorporation of waste carpet fibers and POFA decreased the workability of concrete. The experimental results revealed that the incorporation of 16% POFA and 0.5% PP waste carpet fibers enhanced the long-term compressive and tensile strength of water-cured specimens up to 20%. The positive interaction amongst POFA and waste carpet fibers subsequently reduced the crack formation and spalling, and reduction in strength loss of the concrete specimens exposed to acid and sulfate solutions. The findings of the study demonstrated that the utilization of PP waste carpet fibers along with POFA in the production of a new alternative concrete composite exposed to corrosive solutions is viable technically and environmentally.

Evaluation of the Effective Mechanical Properties of Concrete Composites Using Industrial Waste Carpet Fiber

Synthetic waste fibers are cheap and popular materials used in the concrete, and they may positively affect the properties of cementitious composites because of their superior properties. This research proposes the utilization of waste carpet fiber and palm oil fuel ash (POFA) to develop the physical, mechanical and microstructural properties of concrete. Carpet fiber of 20 mm length and six volume fractions of 0, 0.25, 0.5, 0.75, 1.0 and 1.25% were used with ordinary Portland cement (OPC). Another six mixes were made that replaced OPC with 20% POFA. The combination of carpet fiber and POFA decreased the slump values and increased the VeBe time of fresh concrete. Likewise, the addition of carpet fiber, either into OPC or POFA concrete, did not improve the compressive strength. However, the positive interaction between the carpet fiber and POFA lead to higher tensile and flexural strengths. Despite lower strength development, an increment in the post-failure compressive strength of concrete composite was observed in all mixes. A significant enhancement was also observed in impact resistance of the concrete composite containing carpet fiber, as compared to that of plain concrete. Microstructure of concrete was examined by using scanning electron microscope. It is revealed that carpet fibers act as bridges across the cracks, which improve the load-transfer capacity of the matrix. The study showed that the utilization of waste carpet fiber and POFA in the production of concrete is feasible from both technical and environmental points of view.

RETRACTED: Microstructure and residual properties of green concrete composites incorporating waste carpet fibers and palm oil fuel ash at elevated temperatures

With the increasing amount of waste generation from different processes, there has been a growing interest in the use of waste in producing sustainable building materials to achieve potential benefits. This study investigated the influence of waste polypropylene carpet fibers and palm oil fuel ash (POFA) on the microstructure and residual properties of concrete composites exposed to elevated temperatures. Four mixes containing carpet fibers (0% and 0.5%) and POFA (0% and 20%) were prepared. The specimens were exposed to high temperatures (200, 400, 600 and 800 °C) for 1 h. The fire resistance of the concrete specimens was then measured in terms of mass loss as well as both residual ultrasonic pulse velocity (UPV) and compressive strength. The role of carpet fibers and POFA was investigated through the analysis of the microstructure in terms of scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The results revealed that the addition of waste polypropylene carpet fibers to the concrete matrix significantly enhanced the fire resistance and residual compressive strength in addition to eliminating the explosive spalling behavior of the concrete composites at elevated temperatures. The fire resistance of the concrete mixtures was further enhanced by the inclusion of POFA. The study revealed that the utilization of waste carpet fiber and palm oil fuel ash in the production of sustainable green concrete is feasible both technically and environmentally.

RETRACTED: Durability performance of green concrete composites containing waste carpet fibers and palm oil fuel ash

Cleaner production is a pressing concern of the 21st century. Waste materials resulting from different industrial processes requires proper management to ensure a cleaner environment. The use of recycled materials in new green concrete production is very attractive due to the low-cost related to the waste materials in addition to saving required space for landfill purposes and the development as well as improvement in the concrete properties. This paper focuses on the durability properties of green concrete composite, which comprised of waste polypropylene (PP) carpet fiber and palm oil fuel ash (POFA). Properties studied include slump and VeBe time of fresh concrete as well as water absorption, sorptivity, chloride penetration, carbonation, and drying shrinkage of hardened concrete. Carpet fiber of 20 mm in length and six volume fractions of 0–1.25% were used with ordinary Portland cement (OPC). Another six concrete mixes were cast whereby OPC was replaced by 20% POFA. It was observed that the combination of PP carpet fiber and POFA decreased the slump values and increased the VeBe time of the fresh concrete mixes. In addition, water absorption, sorptivity, chloride penetration, and carbonation depth of the concrete composite for both OPC and POFA content mixtures were reduced with the addition of carpet fiber, with volume fractions of up to 0.75%. The positive interaction between carpet fibers and POFA subsequently led to the lower drying shrinkage of the concrete composite. The influences of POFA on the durability performance of concrete was observed to be more significant at longer curing periods. The findings of the study demonstrated that there is a promising future for the use of waste carpet fibers as a fibrous material in the production of a green and durable concrete. Green concrete also minimizes solid wastes, improves air quality, and leads to sustainable cement and concrete industry.

Optimization of carpet waste fibers and steel slag particles to reinforce expansive soil using response surface methodology

Expansive soils exhibit great volume change with any moisture variation. In this paper, using carpet waste fibers and steel slag as an environmental friendly additives were taken into account to overcome the swelling and weakness of the expansive soil. Response surface methodology (RSM) was employed to design the experiments, evaluate the results and finally optimize the content of slag-fiber mixture for achieving appropriate values of swell percent, swelling pressure and unconfined compressive strength (UCS). Three independent variables including slag content (0–25% by dry weight of the soil), carpet waste fiber (0.2–3% by dry weight of the soil) and aspect ratio of fibers L/d (5–45) were considered and transformed to coded value, and a second-order polynomial regression equation was then derived to predict responses. The percentage contribution, validity of model and significance of independent variables and their interaction were assessed by analysis of variance (ANOVA). The optimum values of three independent variables was suggested as 14% slag and 0.78% fiber with fiber aspect ratio of 45 to improve swell percent, swelling pressure and UCS 89%, 84%, and 111%, respectively. The results showed that both chemical modification and mechanical reinforcement by adding fibers and slag are efficient methods to improve general properties of expansive clayey soil.

Analysis of Strip Footings on Fiber-Reinforced Slopes with the Aid of Particle Image Velocimetry

AbstractThis paper provides results of a comprehensive investigation into the use of waste carpet fibers for reinforcement of clay soil slopes. The interaction between laboratory scale model slopes made of fiber-reinforced clay soil and surface strip footing load was examined. Results for the influence of two variables, namely fiber content and distance between the footing edge and the crest of the slope, are presented and discussed. The particle image velocimetry (PIV) technique was used to study the deformation of the slope under the surface loading. The front side of the tank was made of a thick Perspex glass to facilitate taking accurate images during the loading stage. To study the stress induced in the slope under footing pressure, excess pore-water pressure and total stress increase were measured at predetermined locations within the slope. The results showed that fiber reinforcement increased the bearing resistance of the model slope significantly. For instance, inclusion of 5% waste carpet fiber ...

Green concrete production incorporating waste carpet fiber and palm oil fuel ash

With the increasing amount of waste generation from various processes, there has been a growing interest in the utilization of waste in producing building materials to achieve potential benefits. This paper highlights the results of an experimental investigation on the performance of concrete incorporating waste carpet fiber (WCF) and palm oil fuel ash (POFA) as partial replacements of ordinary Portland cement (OPC). Six volume fractions varying from 0 to 1.25% of 20-mm-long carpet fiber were used with OPC concrete mixes. Another six mixes were made that replaced OPC with 20% POFA. The specimens were cured in water and tested for fresh and hardened state properties. The combination of WCF and POFA decreased the slump values and increased the VeBe time of fresh concrete. The addition of WCF to either OPC or POFA concrete mixes did not improve the compressive strength or modulus of elasticity. At 91 days, the compressive strength was in the range of 38.1–49.1 MPa. The positive interaction between WCF and POFA, however, leads to high tensile and flexural strengths, thereby increasing the concrete ductility with higher energy absorption and improved crack distribution. The maximum increases in tensile and flexural strengths compared to those of plain concrete were achieved by the addition of 0.5% carpet fiber at the age of 91 days. The ultrasonic pulse velocity (UPV) was examined and was classified as good quality concrete. The study showed that the use of waste carpet fiber and palm oil fuel ash in the production of sustainable green concrete is feasible both technically and environmentally.

STRENGTH, MODULUS OF ELASTICITY AND SHRINKAGE BEHAVIOUR OF CONCRETE CONTAINING WASTE CARPET FIBER

This paper presents test results on some physical and mechanical properties of concrete containing fiber from recycled carpet waste. Five concrete mixes namely plain concrete (PC) i.e. concrete without carpet fiber, as control and carpet fiber reinforced concrete (CFRC) mixes containing 0.5%, 1.0%, 1.5% and 2.0% polypropylene (PP) waste carpet fibers were made and tested for compressive, tensile and flexural strengths, modulus of elasticity and shrinkage at curing periods of 1, 7 and 28 days. It has been found that the addition of carpet fiber reduced the workability and density of concrete. Concrete containing carpet fiber exhibited lower compressive strength and modulus of elasticity than plain concrete. The carpet fibers, however, effectively improved the splitting tensile and flexural strengths of concrete. The obtained values of shrinkage revealed that the shrinkage strain of carpet fiber reinforced concrete was higher than that of plain concrete. On the basis of short-term investigation, the one-year shrinkage values of both plain concrete and concrete containing carpet fiber were also predicted by extrapolating the data obtained during this period. The results obtained in this study indicate that waste carpet fiber can suitably be used as fiber reinforcement in concrete with satisfactory performance.

Unconfined Compression Strength of Reinforced Clays with Carpet Waste Fibers

This paper presents results of a comprehensive investigation on the utilization of carpet waste fibers in reinforcement of clay soils. Effects of adding proportionate quantities of two different types of shredded carpet waste fibers to clay soils (i.e., 1, 3, and 5% by dry weight of the soil) were investigated and evaluated. The investigation was conducted on specimens prepared at their maximum dry unit weight and optimum moisture content, as well on specimens prepared at variable conditions of dry unit weight and moisture content. A comparison was also made on specimens prepared at the same fiber content by changing dry unit weight while moisture content was kept unchanged or by changing both dry unit weight and moisture content. The investigation revealed that inclusion of carpet waste fibers into clay soils prepared at the same dry unit weight can significantly enhance the unconfined compression strength (UCS), reduce postpeak strength loss, and change the failure behavior from brittle to ductile. The results also showed that the relative benefit of fibers to increase the UCS of the clay soils is highly dependent on initial dry unit weight and moisture content of the soil. Failure patterns were gradually transformed from the apparent classical failure for unreinforced soil specimens to barrel-shaped failures for reinforced specimens at 5% fiber content.

Research on Mechanical Properties of Recycled Fiber Concrete

At present, green energy saving idea, aimed at protecting environment and saving energy, now has become the guiding philosophy of modern architecture. Based on this, recycled carpet waste fibers for textile mechanical properties of concrete were discussed in this paper. The application of polypropylene fiber concrete abroad has been widely used, which is becoming more and more popularly in China recent years. Meanwhile, research on the application of recycled polypropylene fiber concrete is still scarce. The experiment of this paper adopt waste polypropylene fibers as reinforcing fiber, and we make the standard specimen which size is . We use the specimen to do the research of mechanical properties of compressive strength and observing the variation of compressive strength of concrete specimen in different fiber volume. We discovered that when we add volume of 0.12% recycled polypropylene fiber and the length is 19mm, the compressive strength of concrete increases greatly. We draw the conclusion that the compressive strength of recycled fiber concrete is better than ordinary one from the experiment. In addition, if such concrete was used widely, we may reach the goals of conserving resources and protecting the environment.

Utilization of recycled post consumer carpet waste fibers as reinforcement in lightweight cementitious composites

Purpose – A large amount of post‐consumer carpet waste is discarded into landfills. The need to recycle this waste is increasing due to the lack of available landfill spaces in many parts of the world, environmental concerns, and resource conservation. The purpose of this paper is to explore the use of this waste for a low‐cost, high‐volume application.Design/methodology/approach – Fibers from carpet waste have been successfully used as reinforcement in concrete, typically at 0.1‐1 per cent volume fraction (fractions by weight are even lower), for enhanced toughness. In this study, lightweight cementitious composites were fabricated that were reinforced with recycled carpet fibers at up to 20 per cent fiber to cement weight ratios. Flexural, toughness, and impact properties of the lightweight cementitious composites were characterized.Findings – The density of the composites decreases with the increase of fiber content. In the three‐point bending test, lightweight cementitious composites exhibited a ducti...

Properties of cementitious composites containing polypropylene fiber waste

The carpet waste fibers and waste glass that create a serious environmental problem can be converted into useful products. The use of these waste materials in a cement-based composite can be a promising direction for waste reduction and resources conservation. In this study, several tests have been carried out to investigate the performance of control mortar using recycled glass and fibers as a fraction of aggregates in a cement-based composite. These tests included compressive strength, flexural strength, flexural toughness and water absorption. The results revealed that carpet waste fiber and waste glass could be reused as substitutes for conventional materials in cement-based composites.

Utilization of Recycled Carpet Waste Fibers for Reinforcement of Concrete and Soil

The use of recycled fibers from textile waste for concrete and soil reinforcement is a very attractive approach, with such benefits as performance enhancement, low-cost raw materials, and reduced needs for landfilling. This article discusses the general advantages of fiber reinforcement and reviews some studies on the use of carpet waste fibers for concrete and soil reinforcement. A study on recycled carpet waste fibers for fiber-reinforced concrete (FRC) showed a significant toughness increase and reduced shrinkage. It included two concrete mix designs and a wide range of fiber dosage rates, from 0.07 to 2.0 vol.%. A research program on fiber-reinforced soil is underway for fiber characterization, analysis of the engineering properties of the fiber-soil systems, and field trials. A significant improvement in soil behavior under the triaxial loading condition was observed.