Use Of Waste Tire Rubber Research Articles

Investigation of the Shear and Pore Structure Characteristics of Rubber Fiber-Reinforced Expansive Soil

In recent years, many researchers have evaluated the sustainable use of waste tire rubber as an aggregate in soil. Its effectiveness has been widely acknowledged. The main objective of this work is to study the influence of rubber fibers on shear strength and pore structure characteristics in relation to expansive soil. In this context, we conducted a series of experiments that were carried out on reinforced expansive soil with rubber fiber contents of 0, 5, 10, 15, and 20%. The results show that the shear strength and maximum dilatation angle increase gradually with rubber fiber content. Due to the pore water pressure and creep effects, the deviator stress and effective cohesion of the samples under the consolidated drained conditions were higher than those under the undrained conditions. The converse was true for the internal angle. The addition of an appropriate amount of (5–10%) rubber fiber can effectively inhibit the development of soil cracks and reduce the porosity of the samples. The results obtained can highlight the beneficial effects of rubber fiber, which is highly desirable in many backfill applications.

Remanufactured waste tire by-product valorization: Quantitative–qualitative sustainability-based assessment

Automotive tires are a major waste stream and there are currently numerous options for reusing, recycling, and remanufacturing the waste tire rubber (WTR) and other components. Some competing technologies (retreading, product repurposing, energy recovery, pyrolysis oil, waste-tire crumbing, and devulcanized rubber) are discussed here to demonstrate the broad scope of possible applications and identify the advantages/disadvantages of the processes. Based on the industrial maturity of the processes, this study performed a qualitative–quantitative fuzzy analysis of twelve alternative by-products of WTR, including 1) devulcanized or desulfurized rubber; 2) tiles, mats, and rod barriers; 3) composite materials; 4) bitumen; 5) asphalt; 6) heat energy; 7) crude oil; 8) diesel; 9) char and carbon black; 10) gasification gas; 11) activated adsorption carbon; and 12) lightweight concrete. Quantitative sustainability considerations were applied to weight the technical, economic, environmental, and social sustainability factors according to their importance, while qualitative factors were applied to weight the sustainability criteria of productivity, reliability, efficiency, waste tire size range, remanufacturing time, remanufacturing cost, ergonomics, human development, and employment potential based on insights from the published literature. Comparative literature-based statistical analysis of potential tire resources and conventional waste-tire recycling was performed. The results identified remanufacturing of WTR into devulcanized rubber sheets as the best sustainable business option with the highest sustainability index of 0.628, while lightweight concrete was the worst by-product option with a low sustainability index of 0.012. Other very-high-potential options include producing value-added rubber products and composite materials from the devulcanized rubber. These findings provide valuable insights for stakeholders in the field of waste-tire management and small-to-medium businesses looking to add further value to their WTR products. Furthermore, these findings could guide international research to help focus on the most sustainable use of WTR.

High strength rubberized porous concrete for sustainable pavements: Engineering properties and life cycle assessment

This study investigates the performance of Pervious Concrete (PC) with varying quantities of Natural Coarse Aggregate (NCA) replaced by Waste Tire Rubber (WTR) (5%, 10% and 15% by weight) whereas Silica Fume (SF) (5%, 10% and 15%) and Fly Ash (FA) (10% constant) were employed as substitute for cement. This research aims at optimizing the mix of High Strength Rubberized Pervious Concrete (HSRPC) using Supplementary Cementitious Materials (SCMs), comparing experimental stress-strain graphs with the developed constitutive models and conducting a Life Cycle Assessment (LCA). Physical and mechanical performance of PC were examined using permeability and strength indices. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) observed microstructural variations and Interfacial Transition Zone (ITZ) development. The use of WTR increased the permeability and decreased the strength indices. The permeability of mixes with 5, 10 and 15% WTR was found to be 4.00, 4.21 and 4.49 mm/s, which were more than control mix permeability. The compressive strength of PC with 5%, 10%, and 15% WTR was determined to be 32.48, 29.29, and 26.94 MPa, respectively, which were lower than control PC compressive strength which was 35.41 MPa. However, the addition of SF and FA enhanced the mechanical properties while causing a decrease in the permeability. Increasing SF content from 0% to 15% enhanced the compressive strength of PC containing 5% WTR, from 32.48 to 40.71 MPa. Developed constitutive models compared the stress-strain response of PC. Life cycle assessment showed that WTR, SF, and FA-based PC reduced the global warming.

Stabilization of Soil by Use of Waste Tyre Rubber

In India, the scrap or waste tyres are being generated and accumulated in huge volumes causing an increasing hazard to the environment. In order to eradicate the negative effect of these confessions and in terms of sustainable development, there is great interest in the recycling of these non-hazardous solid wastes. So we can stabilize the soil by using waste tyre rubber, which is available as a waste in more numbers. The objective of this study is to study the improvement of bearing capacities of the clay soil using waste tyre rubber. To examine the optimum moisture content present in the soil by using waste tyre rubber and also to study the improvement of settlement of clay soil by using waste tyre rubber.

Post-fire flexural behavior of functionally graded fiber-reinforced concrete containing rubber

The optimal distribution of steel fibers over different layers of concrete can be considered as an appropriate method in improving the structural performance and reducing the cost of fiber-reinforced concrete members. In addition, the use of waste tire rubber in concrete mixes, as one of the practical ways to address environmental problems, is highly significant. Thus, this study aimed to evaluate the flexural behavior of functionally graded steel fiber-reinforced concrete containing recycled tire crumb rubber, as a volume replacement of sand, after exposure to elevated temperatures. Little information is available in the literature regarding this subject. To achieve this goal, a set of 54 one-, two-, and three-layer concrete beam specimens with different fiber volume fractions (0, 0.25, 0.5, 1, and 1.25%), but the same overall fiber content, and different volume percentages of the waste tire rubber (0, 5, and 10%) were exposed to different temperatures (23, 300, and 600oC). Afterward, the parameters affecting the post-heating flexural performance of concrete, including flexural strength and stiffness, toughness, fracture energy, and load-deflection diagrams, along with the compressive strength and weight loss of concrete specimens, were evaluated. The results indicated that the flexural strength and stiffness of the three-layer concrete beams respectively increased by 10 and 7%, compared to the one-layer beam specimens with the same fiber content. However, the flexural performance of the two-layer beams was reduced relative to those with one layer and equal fiber content. Besides, the flexural strength, toughness, fracture energy, and stiffness were reduced by approximately 10% when a 10% of natural sand was replaced with tire rubber in the threelayer specimens compared to the corresponding beams without crumb rubber. Although the flexural properties of concrete specimens increased with increasing the temperature up to 300oC, these properties degraded significantly with elevating the temperature up to 600oC, leading to a sharp increase in the deflection at peak load.

Evaluation of rubber powder waste as reinforcement of the polyurethane derived from castor oil

Waste tire rubber is produced on a large scale in the automotive industry and is considered difficult to recycle because they have iron, nylon, polyester, and chemical structure formed by cross-links. In this way, the waste is almost always deposited in inappropriate places or incorrectly burned, causing a series of environmental problems. The objective of this work was to analyze the viability of the use of waste tire rubber (5, 10, and 20% m/m) reinforced in polyurethane foam (PU) derived from castor oil to obtain composites, as an alternative for raw materials petrochemical industrial. The materials were characterized by scanning electron microscopy (SEM), optical microscopy (OM), apparent density, contact angle, water absorption, X-ray diffractometry (XRD), spectroscopy infrared (FTIR), thermogravimetry (TGA) techniques, and mechanical tests. The results showed that the residue of the rubber powder reinforced with polyurethane caused an increase in the density of the composites when compared to pure PU, which directly influenced the morphological, physical, thermal, and mechanical properties. This fact occurred because with the insertion of rubber powder in the PU there was a decrease in cell size and increase of pore volume. The TG and DTG analyzes showed that the insertion of the rubber powder improved the thermal stability of the composite when compared to pure PU, as well as impact tests and contact angle.

An Experimental Study on Behavior of Sustainable Rubberized Concrete Mixes

In terms of recycling and reuse, today's global generation of waste tire well exceeds its consumption. This has resulted in the accumulation of large stocks of toxic rubber waste that raise health and safety risks. The use of waste tire rubber for the construction of the concrete structure was suggested to combat this challenge. This paper explores tests that were performed with samples of waste tire rubber concrete to evaluate compressive strength, flexural tensile strength, modulus of rupture, and impacts resistance. The main parameters investigated were the rubber ratio as a partial volumetric replacement with fine and coarse aggregate. Chip and crumb rubbers were used to replace coarse and fine aggregate respectively in four different amounts by volume (5%, 10%, 15%, and 20%). Even if the inclusion of waste tire rubber in concrete has specific apparent degradations, the potential benefit seems to overlook the adverse effects and also meet the primary significant value of resolution for rubber waste utilization problems. The results show that the substitution of natural fine or coarse aggregates with crump-chip tier rubber will reduce mechanical properties (compressive, flexural and splitting tensile strength), but increase the impacts resistance to 426% and 396% when 20% coarse aggregates and 20% fine aggregates are replaced by rubber respectively. The proposed mix shows an ability to replace 20% of the aggregate (coarse or fine), and the producing, rubcrete, still structural concrete.

Waste Tire Rubber-based Refrigerants for Solid-state Cooling Devices

Management of discarded tires is a compelling environmental issue worldwide. Although there are several approaches developed to recycle waste tire rubbers, their application in solid-state cooling is still unexplored. Considering the high barocaloric potential verified for elastomers, the use of waste tire rubber (WTR) as a refrigerant in solid-state cooling devices is very promising. Herein, we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber (VNR) and WTR, to evaluate its feasibility for solid-state cooling technologies. The adiabatic temperature changes and the isothermal entropy changes reach giant values, as well as the performance parameters, being comparable or even better than most barocaloric materials in literature. Moreover, pure WTR and WTR-based samples also present a faster thermal exchange than VNR, consisting of an additional advantage of using these discarded materials. Thus, the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects, contributing to both the recycling of polymers and the sustainable energy technology field.

Effect of Elevated Temperature on Concrete Containing Waste Tires Rubber

Our present study aims to investigate the optimal use of waste tire rubber as a fine aggregate in concrete and their sensitivity to high temperature effect. Five different concrete compositions were prepared: a reference concrete (RC) made with natural fine aggregate (sand) and coarse aggregate (dolomite) and four concrete mixes with replacement rates of 4%, 8%, 12% and 16% of sand by crumb rubber from waste tires. For the effect of elevated temperature: Similar specimens were exposed to a period of 4 hours to temperature of 70°C, to study the effect of high daily temperature, and a period of 2 hours for both temperatures 200° C and 400° C to study the effect of fire. After cooling down to ambient temperature, the compressive strength, flexural strength and the splitting tensile strength were measured and compared with the values that obtained before fire exposure. The in-hand study indicates a gradual decrease in compressive, splitting and flexural strengths of concrete for partial substitution of crumb rubber aggregate in concrete. In addition, more decrease in these strength values are resulted after exposing the similar specimens to high temperature. While the inclusion of rubber particles reduces the rate of compressive strength loss at high temperature.

Selective absorption of swelling rubber in hot and warm asphalt binder fractions

The use of waste tire rubber as asphalt modifier has been a practice-ready technology. However, the interaction among components within asphalt rubber (AR) and warm asphalt rubber (WAR) is still unclear. During the blending process, the swelling rubber releases polymer agents in asphalt and absorbs components from both asphalt and warm mix asphalt (WMA) additive simultaneously. The component interaction significantly influences the final rheological properties. A comprehensive understanding of the selective absorption of crumb rubber during the blending process provides references to optimize the material and procedure design of rubberized asphalt. To this end, one AR and two WARs were prepared with three mixing durations. The liquid phases and crumb rubber particles were separated. The separated swelling rubber particles were then processed by the staged extraction method to divide the asphalt-rubber interacting area from outside to inside into four layers. The absorption preference of swelling rubber and its influence on rheological properties were investigated by chemical and rheological tests. Test results showed that asphalt fractions with smaller molecular weight were absorbed into deeper layers of swelling rubber. By contrast, crumb rubber was found to be reluctant to absorb the fractions with CO bond during the mixing process. In addition, the Fischer Tropsch (FT) wax showed a negligible influence on the absorption preference, while the effect of surfactant on absorption preference was significant. Finally, the relationship between absorption preference and rheological properties was established. It was found that the absorption preference of crumb rubber is beneficial to the rutting resistance of rubberized asphalt.

Strength Properties of Tyre Rubber Concrete

Due to the fast development in vehicle industry, utilization of tyre is expanding everyday and there is no reuse of the equivalent to diminish the natural contamination. The transfer of waste tyres is confronting serious issues in India. The developing issue of waste tyre transfer in India can be eased if new reusing courses can be found for the surplus tyres. It is evaluated that 1.2 billions of waste tyre rubber delivered all inclusive in a year. It is assessed that 11% of postconsumer tyres are traded and 27% are sent to landfill, accumulated or dumped wrongfully and just 4% is utilized for structural building ventures. Subsequently endeavors have been taken to distinguish the potential utilization of waste tyres in structural building ventures.In this present study, cubes are casted of M25 grade by replacing 5, 10, 15 percent of tyre rubber aggregate with coarse aggregate and compared with regular M25 grade concrete. Properties of fresh concrete like workability, compressive strength,split tensile strength,flexural strength of hardened concrete were identified. The aim is to investigate the optimal use of waste tyre rubber as coarse aggregate in concrete composite.

Eco-friendly concrete with scrap-tyre-rubber-based aggregate – Properties and thermal stability

Increasing amount of waste tyres represents a global problem as tyres can pose a risk to the environment if not treated properly. Recycling of waste tyre rubbers in civil engineering as aggregate in cement concrete can be an effective environmental and economic approach. As problems associated with the use of waste tyre rubber in concrete production are not completely understood, a detailed analysis of rubber concrete prepared from used tyre rubber-based aggregate involving testing of its mechanical, basic physical, microstructural, hygric and thermal properties, and behaviour after exposure to elevated temperatures is presented in this paper. Testing of mechanical performance included measurement of compressive strength, flexural strength, secant and dynamic modulus of elasticity. Thermal conductivity was determined in the dependence on moisture content, from the dry to fully water saturated state. Dry volumetric heat capacity was also tested. Specific attention was paid to the hygric performance of rubberized concrete that was characterised by the water and water vapour transport parameters. Investigation of concrete properties after its thermal exposure included testing of mass loss, mechanical resistance, bulk density, and thermal conductivity that was tested as property having direct relation to concrete structural parameters. The use of scrap-tyre-rubber aggregate resulted in a decrease of the unit weight, worsening in mechanical parameters and a significant reduction in thermal conductivity of prepared rubberized concrete. Rubber-based aggregate almost did not affect water transport properties, while water vapour transport properties increased with rubber amount in the mix. No significant changes on concrete characteristics related to rubber incorporation occurred at temperatures up to 300 °C. However, after exposure to 400 °C, significant changes in measured concrete properties were observed, which was in line with the thermogravimetric analysis of the used tyre-based rubber. Nevertheless, based on rubberized concrete functional properties at common ambient conditions it can be considered as an alternative lightweight material, bringing benefits to the environment and economy as it is produced from crap available in a large amount and at a negligible cost.

Performance of geopolymer concrete containing recycled rubber

Abstract For the past few years, the construction field industry is responding to the challenge of incorporating sustainability in the production processes, this was done through the utilization of solid waste materials as aggregates in concrete or via searching for more environmentally friendly raw materials. Producing binders free of Portland cement is one of the most innovative ways to substitutes the Portland cement. Using a cementitious material (steel slag or blast furnace slag) or pozzolanic materials (fly ash or silica fume) activated with alkali activators. These alkali-activated binder systems are called geopolymer concrete. One of the possible solutions for the use of waste tire rubber is to incorporate into geopolymer concrete as a substitution of natural aggregate. This study designed to investigate the effect of different percentages of crumb rubber as a partial substitution of both; fine, and coarse aggregates by volume percentage (0, 10, 20 and 30%) on the hardened properties (compressive, tensile and flexural strength) and impact resistance of slag based geopolymer concrete (replacing the cement by; ground granulated blast furnace slag (GGBFS) activated with sodium silicate and sodium hydroxide). Finally, the work provides the mix with high compressive strength, ductility and impact resistance to be used in structural elements subjected to impact and dynamic load such as (bridge approach slabs, railway buffers, and airport runways).

Manufacture of structural blocks of concrete with waste tire rubbers

The construction industry is a major consumer of natural resources and is directly related to the technological and industrial growth of the country. Various segments of society have turned to the concepts of sustainability, seeking alternatives to reduce the impacts caused by the use, in most cases, indefinite of raw material and by the large volume of waste generated, include the waste tire rubber. The use of waste as raw materials in construction, as well as minimize the extraction of natural resources, such as sand and gravel, can also reduce the accumulation of these tailings in urban areas, making it also a technical solution bringing benefits the buildings as: reduced density, better drainage and property improvement in thermal and acoustic insulation. The present work aims to demonstrate the use of waste tire rubber as aggregate in concrete building blocks, showing the relationship between the term sustainability and your application, viaare the production of bodies of evidence produced in the laboratory by assessing their physical and mechanical properties.

A review of Waste Tyre Rubber as an Alternative Concrete Consituent Material

The current global waste tyre generation far exceeds its consumption in terms of recycling and re-use. The traditional recycling and re-use methods like thermal incineration have proven ineffective, costly and in some cases environmentally unsustainable. Particularly, in developing countries where some of the sophisticated techniques required to process tyres to allow them to be utilised are either too costly or have not yet been developed. The situation has resulted in accumulation of large waste tyre stockpiles that pose health and safety risks. To combat the problem, the use of waste tyre rubber in concrete construction has been proposed. Several studies have been conducted to assess the effects of the inclusion of waste tyre rubber in its different forms (fibres, particles), for concrete production and the results are promising. Although there are some apparent demerits to the inclusion of tyre rubber in concrete, the potential benefits seem to overshadow the negatives. This paper reviews published research on the scientific and technical viability of using waste tyre rubber in concrete production. It discusses the production and properties of waste tyre particles. It highlights advances made with regards to the incorporation of tyre rubber material in concrete, focusing on the engineering properties of the tyre rubber modified concrete. In conclusion, recommendations for future research and possible application for the material will be discussed.

Use of Recycled Tyre Rubber in Non-structural Concrete

To manage tyre waste and conserve natural aggregate resource, this research investigates the use of waste tyre rubber as partial replacement of fine aggregates in non-structural concrete. The research used Taguchi method to study the influence of mix proportion, water-to-cement ratio and tyre rubber replacement percentage on concrete. Nine mixes were prepared with mix proportion of 1:2:4, 1:5:4 and 1:2.5:3; water-to-cement ratio of 0.25, 0.35 and 0.40 and rubber to fine aggregate replacement of 20%, 30% and 40%. Compressive strength and water absorption tests were carried out on 100 mm cubes. Compressive strength was directly proportional to the amount of coarse aggregate in the mix. Water-to-cement ratio increased the strength within the range used in the study. Strength was found to be more sensitive to the overall rubber content than the replacement ratio. Seven out of the nine mixes satisfied the minimum strength requirement for concrete blocks set by ASTM. Water absorption and density for all mixes satisfied the limits applicable for concrete blocks. The study indicates that mix proportions with fine to coarse aggregate ratio of less than 1.0 and w/c ratio around 0.40 can be used with tyre rubber replacements of up to 30 % to satisfy requirements for non-structural concrete.

Compressive Strength and Modulus of Elasticity of Concrete with Cubed Waste Tire Rubbers as Coarse Aggregates

One feasible solution to overcome the issue of tire disposal waste is the use of waste tire rubber to replace aggregate in concrete. We have conducted an experimental investigation on the effect of rubber tire waste aggregate in cuboid form on the compressive strength and modulus of elasticity of concrete. The test was performed on 72 cylindrical specimens with the height of 300 mm and diameter of 150 mm. We found that the workability of concrete with waste tire rubber aggregate has increased. The concrete density with waste tire rubber aggregate was decreased, and so was the compressive strength. The decrease of compressive strength is up to 64.34%. If the content of waste tire rubber aggregate is more than 40%, then the resulting concrete cannot be categorized as structural concrete. The modulus of elasticity decreased to 59.77%. The theoretical equation developed to determine the modulus of elasticity of concrete with rubber tire waste aggregate has an accuracy of 84.27%.

Moisture damage resistance of hot-mix asphalt made with recycled concrete aggregates and crumb rubber

To guarantee sustainable construction, we investigated the reuse of construction and demolition waste (CDW) as recycled concrete aggregate (RCA) for the manufacture of hot-mix asphalt (HMA) in place of natural aggregates. The use of waste tire rubber as a bitumen modifier could be a means of improving the water resistance of these mixtures. In this investigation, moisture damage resistance of HMA for binder course, type AC 22 bin S, was analysed. Percentages of 0% (control mixture), 35% and 42% RCA were used in place of natural aggregates. Two types of bitumen have also been used: a conventional B35/50 penetration grade bitumen and BC35/50, a crumb rubber modified bitumen. Volumetric properties and water resistance were determined by means of indirect tensile tests. The results indicate that contrary to expectations, mixtures made with BC35/50 do not display better water resistance than mixtures made with B35/50. Nevertheless, a mixture made with B35/50 or BC35/50 does comply with Spanish requirements. Additionally, reversibility of moisture damage resistance was clearly demonstrated in this research. This research may help to better understand the performance of HMA made with RCA and the drawbacks of using waste tire rubber as a bitumen modifier.

Long term behaviour of cement concrete containing discarded tire rubber

Disposal of waste tire rubber has become one of the major environmental issues in the world. Every year millions of tires are discarded, thrown away or buried all over the world, representing a very serious threat to the ecology. It was estimated that, almost 1000 million tires end their service life every year and more than 50% are discarded without any treatment. One of the possible solutions for the use of waste tire rubber is to incorporate into cement concrete, to replace some of the natural aggregates. This paper presents the results of an experimental research to analyse the suitability of waste tire rubber as a partial substitute for natural fine aggregates in cement concrete. For the first time, three sizes of crumb rubber were mixed in definite percentages and replaced for fine aggregates from 0% to 20% in multiples of 2.5%. Tests were done to determine the mechanical properties, water absorption, resistance to sulphate attack, carbonation and porosity of these concrete samples. It was observed that the values of compressive strength, flexural tensile strength, pull-off strength and sulphate attack of rubberized concrete were lower than that of control mix; but up to a certain percentage, they gave better resistance to water absorption, and carbonation. It was concluded that there is a promising future for the use of discarded tire rubber as a partial substitute for fine aggregates in concrete, which can result in huge environmental and sustainability benefits.

Performance of high strength rubberized concrete in aggressive environment

Due to the huge increase in the population and number of vehicles, lots of tyres are ending as waste every day. It was estimated that every year almost 1000 million tyres end their useful life and more than 50% are discarded without any treatment. One of the possible solutions for the effective use of waste tyre rubber is to incorporate into cement based materials, to replace some of the natural aggregates. In this study, waste tyre rubber in the form of crumb rubber was used as a partial replacement for natural fine aggregates in high strength cement concrete. Crumb rubber was replaced for fine aggregates from 0% to 20% in multiples of 2.5%. Tests were done to determine the depth of carbonation, water absorption of acid attacked specimens, compressive strength of acid attacked specimen, variation in weight of acid attacked specimen and chloride penetration of these concrete samples. From the test results it could be concluded that the high strength rubberized concrete are highly resistant to the aggressive environments.