Shredded Waste Tires Research Articles

Reuse of Waste Materials in Geotechnical Practice

Waste material is an inevitable outcome of most human and industrial activities, lacking enduring value. A significant amount of waste is being generated from various sources such as industrial and domestic activities, driven by population growth and economic expansion. To address these challenges, methods like re-use and recycling are crucial in mitigating the adverse impacts of waste by reducing landfill deposition. Recycling not only helps in conserving natural resources but also diminishes energy consumption. Recently, there has been increasing interest in re-using waste materials as substitutes in geotechnical and geo-environmental applications. For the efficient utilization of waste, it is essential to systematically understand its characterization, various technical aspects, and environmental implications, along with their interrelationships. This study aims to explore the potential of using different by-products and waste materials such as fly ash, shredded waste tires, and recycled concrete aggregates as geomaterials. By doing so, it endeavours to contribute to sustainable practices in geotechnical engineering. Overall, the re-use of waste materials constitutes a significant area of research aimed at fostering sustainability in geotechnical engineering practices.

Rudimentary Assessment of Waste-to-Wealth of Used Tires Crumbs in Thermal Energy Storage

Disposing of waste tires is a major environmental and economic issue. Different recycling methods have been studied to account for its re-usage. This project aims to evaluate the possible usage of shredded waste tires in thermal energy storage (TES) applications, whether they are sensible or latent materials. An experimental setup has been developed with seven compartments. Each compartment contains different TES materials, including tire crumbs, paraffin wax, paraffin wax with shredded tires, pebbles, pebbles with shredded tires, concrete, and concrete with shredded tires. In all cases of the mixture, the base materials are 60%vol, and the tire crumbs are 40%vol. The experimental included three locations for temperature measurements in each compartment, solar irradiation, and ambient temperature. The tests were carried out from 9:00 a.m. till 7:00 p.m. and repeated for five days to account for the weather’s daily change. Results revealed that mixed 60%vol pebbles and 40%vol shredded tires have the highest recorded temperature, at 112.5 °C, with a 39.5% increment compared to pure pebbles. The interesting finding is that the added tire crumbs reduced the storage capacity of the paraffin wax, which is latent TES material. At the same time, it increased the storage capacity of the concrete and pebbles, which are sensible TES materials. Adding 40%vol of tire crumbs to the paraffin wax has a negative effect, where the thermal storage capacity is reduced by 43%, and the discharge capacity is reduced by 57%. In contrast, the concrete and the pebbles show enhanced storage capacity. Adding 40%vol of crumbs to the concrete increased the charging capacity by 54% and discharging capacity by 33.7%. The 40%vol added tire crumbs to the pebbles increased its charging capacity by 25% and the discharging capacity by 33%. The rudimentary assessment encourages further investigations on using the wasted tires crumbs for TES. The results reveal the probability of a circular economy using wasted tires with sensible TES for solar-to-thermal energy conversion.

Evaluating the effect of using shredded waste tire in the asphalt concrete-binder coarse on Marshall parameters

Shredded Waste Tires are industrial materials that can be used in the asphalt mixture. The use of tires increases every day, considering the number of vehicles that grow from year to year. Using used tires is highly recommended for efforts to reduce waste that will harm the environment. The research aims to see the effect of adding shredded tires in a pavement mixture based on Marshall Value. The AC-BC pavement layer is not directly in contact with wheel load. Still, it must have sufficient thickness and stiffness to minimise stress or strain from traffic loads continuously transferred from the top of the pavement. The most important characteristic of the AC-BC is its stability. The optimum asphalt content value in the AC-BC mixture is 6.81%, mixed with various shredded waste tires. The Asphalt Concrete-Binder Course blended with 1.5%, 3.5%, 5.5% and 7.5% of the various shredded waste tire. The optimum shredded tire content was obtained at 3.5%, with the stability value increased by 2.1% from 1581.98 to 1614.88 kg, with a flow value of 5.43 mm, and a Marshall Quotient value of 297.4 kg/mm.

Experimental Investigation of the Stress-Strain Behavior and Strength Characterization of Rubberized Reinforced Concrete.

Due to the rapid increase in population, the use of automobile vehicles increases day by day, which causes a considerable increase in the waste tires produced worldwide. Research studies are in progress to utilize scrap tires and waste rubber material in several fields to cater the pollution problems in a sustainable and environmentally friendly manner. In this research, the shredded waste tires were used in concrete to replace fine aggregates in different percentages. The fine aggregates in the rubberized concrete were replaced 10%, 15%, and 20% by rubber. The stress–strain behavior of the concrete models is then determined and compared with the already established analytical models, i.e., Modified Kent and Park Model, Mander’s model, and Razvi and Saatcioglu Model. A total of 12 standard concrete cylinders and 18 models of each type of concrete, i.e., normal concrete, reinforced rubberized concrete with 10%, 15%, and 20% addition of rubber, were fabricated. Specimens fabricated in each replacement of rubber were laterally confined, employing 3 in (76 mm) and 6 in (152 mm) c/c tie spacing. The model and cylinders were subjected to uni-axial compression tests using Universal Testing Machine (UTM). The drop in compressive strength, stress–strain constitutive law, strain limits, and overall behavior of the rubberized reinforced concrete were explored experimentally. The results were then compared with the analytical results of the established models. The research can help explore the possible future for the use of rubberized concrete for the potential application as a structural material.

Development of a sustainable community with an integrated renewable and waste to energy system for multiple useful outputs

In this study, a solar energy-based integrated gasification system is designed to produce multiple useful commodities, such as hydrogen, biogas, freshwater, domestic hot water, and power, for a sustainable community. The COVID-19 pandemic has clearly shown society the importance of renewable energy systems and proper waste management systems. In this developed system, shredded waste tires are used to produce energy in the form of hydrogen and the syngas produced at the gasification unit is further utilized for the steam Rankine cycle, and this will be replaced with forward multi-effect desalination unit to produce useful outputs. This hybrid system is also incorporated with integrated anaerobic digestion and composting units to create a circular economy unlike traditional systems. This proposed system is thermodynamically analyzed and dynamically simulated by investigating the effect of dynamic solar intensities throughout the months in a year. Furthermore, the gasification products are analyzed by altering the steam and oxygen feed rate within the system. This system utilizes closed landfills with a renewable energy system, solar tower cycle, to produce energy and steam. This steam is then further utilized at the gasification unit as a gasification agent to increase hydrogen production. The total electricity and freshwater produced within this integrated system is calculated to be 163 MW/h and 2.16 tonnes during its operation in a day. In addition, the hydrogen to fuel ratio at the gasifier and the hourly methane production at the anaerobic digestion unit are found to be 0.175 and 309 m3/h, respectively. The overall energy and exergy efficiencies of this proposed system are observed to be 74% and 73%, respectively.

Shredded Waste Tires as A Stabilizing Material For Unpaved Roads.(Dept.C)

Shredded Waste Tires as A Stabilizing Material For Unpaved Roads.(Dept.C)

Discrete Element Modelling of Rubber-Protected Ballast Performance Subjected to Direct Shear Test and Cyclic Loading

The rubber-protected ballast (RPB) is made from natural ballast particles and crumb rubber particles. The crumb rubber is shredded waste tires. RPB was chosen to replace the ballast as it has higher resistance to breakage and abrasion. However, the static and dynamic performance of the RPB has not been confirmed yet. Towards this end, experimental tests and numerical simulations were utilized to study the feasibility of RPB application. Direct shear tests (DSTs) were performed and a DST model and three-sleeper track model with the discrete element method (DEM) were built. The shear strength, settlement, displacement, and acceleration of the RPB were studied. The results show that the RPB has the advantage of increasing the force (stress) distribution and that the smaller crumb rubber size was more suitable for replacing the ballast particles.

Optimum Mixing Ratio and Shear Strength of Granulated Rubber–Fly Ash Mixtures

Studies on shredded waste tires mixed with sand for fill applications are well documented. In this study, a new composite material from mixture of shredded tires and fly ash as fill material is explored. Shredded waste tires with nominal size equal to 9.5 mm (granulated rubber), and fly ash generated from two thermal power plants are used in the study. The composite material is obtained by mixing different proportions of granulated rubber and fly ash. Granulated rubber content equal to 0%, 10%, 30%, and 60% (by weight of fly ash) in the mixture are tested. Compaction characteristics, optimum mixing ratio, and shear strength properties of the mixtures are determined. The maximum dry unit weight and the optimum water content values ranged between 15%–22.5% and 12.6–14.6 kN/m3, and 10%–27% and 10.5–11.6 kN/m3 for mixtures prepared with fly ashes from two sources. Large-size direct shear apparatus is used to obtain the angle of shearing resistance and apparent cohesion of mixtures at both peak state and at near end-of-test. The shear strength of fly ash and granulated rubber mixture is found to be higher than that of fly ash alone or granulated rubber alone, and the maximum shear strength of the composite material is observed for granulated rubber contents equal to about 60% (by weight of fly ash). The peak shear strength parameters of mixtures, apparent cohesion and friction angle, are found to be in the range 14.9–46.0 kPa and 37.5°–50.1°, respectively. Based on minimum void ratio, optimum mix proportions of granulated rubber and fly ash from two sources ranges between 54%–100% and 81%–185% (by weight of fly ash). Based on shear strength testing, fly ash-granulated rubber mixtures are found to perform better than sand-granulated rubber mixtures.

Evaluating the effect of using shredded waste tire in the stone columns as an improvement technique

In this paper, shredded waste tires are used as a substitution for gravel materials and their effect on stone column’s behavior is investigated. An experimental study is carried out on three sizes of tire shreds, including “Fine tire”, “Medium tire”, and “large tire”. The medium-sized tire shred has the same size as the gravel materials and the other sizes are selected smaller and larger. Thirteen series of large scale direct shear, large oedometer, and constant head permeability tests are carried out in three different volumetric mixture proportions of gravel and tire shreds. The results of the large scale direct shear box and large oedometer tests show an increase in the loading capacity of stone columns for 20% of tire content, however, for tire mixing ratios greater than 20%, the loading capacity of stone column is reduced. Furthermore, 20% of medium-sized tire shreds enhances the loading capacity by 30% and 15%, respectively, with no significant change in permeability. Therefore, it is concluded that the best performance of gravel tire shred admixture is achieved by the medium-sized tire shreds. Eventually, utilizing tire shred as partial replacement for gravel materials is an economic way to enhance the loading capacity of stone columns and also to solve environmental problems.

Shear Resistance of Tire-Derived Aggregate Using Large-Scale Direct Shear Tests

AbstractThis paper presents a large-scale direct shear testing of tire-derived aggregate (TDA) of large sizes (25–75 mm). The objective of this research is to obtain and compare the shear resistances of large-sized TDA and TDA in contact with sand, concrete, and geosynthetics. TDAs are pieces of processed and shredded waste tires that can be used as lightweight and quick fills for embankments, subgrades, and retaining walls. A large-scale direct shear apparatus was designed and constructed. The shear box dimensions were 79 cm wide, 80 cm long, and 122 cm tall. The lower shear box was driven by a hydraulic piston, while the upper shear box remained stationary. The horizontal shear forces, shear displacements, and vertical forces were recorded by an automatic data acquisition system. Three normal loads were applied on the TDA to simulate overburden pressures of 24, 48, and 96 kPa (or 500, 1,000, and 2,000 lb/ft2). Duplicate tests were performed to verify the repeatability. The control tests using sand pro...

Demonstration of the waste tire pyrolysis process on pilot scale in a continuous auger reactor

This work shows the technical feasibility for valorizing waste tires by pyrolysis using a pilot scale facility with a nominal capacity of 150kWth. A continuous auger reactor was operated to perform thirteen independent experiments that conducted to the processing of more than 500kg of shredded waste tires in 100h of operation. The reaction temperature was 550°C and the pressure was 1bar in all the runs. Under these conditions, yields to solid, liquid and gas were 40.5±0.3, 42.6±0.1 and 16.9±0.3wt.% respectively. Ultimate and proximate analyses as well as heating value analysis were conducted for both the solid and liquid fraction. pH, water content, total acid number (TAN), viscosity and density were also assessed for the liquid and compared to the specifications of marine fuels (standard ISO 8217). Gas chromatography was used to calculate the composition of the gaseous fraction. It was observed that all these properties remained practically invariable along the experiments without any significant technical problem. In addition, the reaction enthalpy necessary to perform the waste tire pyrolysis process (907.1±40.0kJ/kg) was determined from the combustion and formation enthalpies of waste tire and conversion products. Finally, a mass balance closure was performed showing an excellent reliability of the data obtained from the experimental campaign.

The use of shredded waste tires to improve the geotechnical engineering properties of sands

A new geo-environmental approach was proposed to use waste tires in certain engineering applications and thereby reduce the potential impact on the environment. This paper presents a laboratory study on the effect of shredded tires on the physical properties of some sands. Shredded tires were passed through US sieve size 4 and mixed with three different types of sands with varying gradations. Each type of sand was mixed with four different percentages of shredded tires: 10, 20, 30 and 40% by dry weight. Direct shear tests were conducted to study the effect of the shredded tires on the shear strength properties of sands, such as angle of internal friction and shear strength. The addition of shredded waste tires increased both the angle of internal friction and the shear strength of the sands. Additionally, a prediction model was developed to calculate the shear strength of sand due to increasing shredded tire content. The shredded tires improved some engineering properties of sand.

Influence of Optimized Tire Shreds on Shear Strength Parameters of Sand

This paper presents the usefulness of optimizing the size of waste tire shreds on shear strength parameters of sand reinforced with shredded waste tires. A relatively, uniform sand has been mixed with randomly distributed waste tire shreds with rectangular shape and compacted at 2° of compaction. Waste tire shreds were prepared with a special cutter in three widths of 2, 3, and 4 cm and various lengths for each shred width. Three shred contents of 15, 30, and 50% by volume were chosen and mixed with the sand to obtain a uniformly distributed mixture. In order to compare the shear strength of different sand.tire shred samples, two compaction efforts in terms of sand matrix unit weights of 15.5 and 16.8 kN/m³ were considered. The results show that the influencing parameters on shear strength characteristics of sand.shred mixtures are normal stress, sand matrix unit weight, shred content, shred width, and aspect ratio of tire shreds. With the selected widths of shreds, compaction efforts, shred contents, and the variations of aspect ratios, it is possible to increase the initial friction angle Φ1 up to 113.5%, that is Φ1 = 67°. The average value for the influence of aspect ratio variations on increase in friction angle of the mixtures for all tests has been found to be about 25%. These average values for lower and higher compacted samples containing different widths and aspect rations were 37.6 and 17.2%, respectively. It has been investigated that for a given width of tire rectangular shreds, there is solely a certain length, which gives the greatest initial friction angle for sand.tire shred mixtures. This is the main contribution of this paper.

128 Release of Zinc from Shredded Waste Tires Designed for Use as a Substrate Amendment

Shredded rubber from automotive waste tires has been proposed as a potential component for use as a potting root substrate. One of the problems with using shredded rubber as a root substrate is that it releases potentially phytotoxic levels of Zn. Therefore, we were interested in washing the rubber particles with either distilled water, 0.1N HCl, or 0.05N DTPA before inclusion of the rubber in the potting mix. A coarse and a fine grade were used. Seventy-two percent (% w/w) of the particles in the coarse grade were within a particle size range of 2.8-6.3 mm, while only 52% of the particles in the fine grade were within this range. The ratio of extractant to shredded rubber was 2:1 (v/v). The soaking time varied from 1 to 96 hours with the extractant changed every 1, 2, 12, or 24 hours. For either particle size, the 0.1N HCl extractant removed 25 times more Zn than the water and 1.5 times more than the DTPA. With the 0.1N HCl extractant, three times more Zn was removed from the fine rubber as compared with the coarse material. Seventy-five percent of the Zn extracted was removed in the first hour of soaking and 92% removed within 72 hours.

Sand Reinforced with Shredded Waste Tires

The objective of this study was to investigate the feasibility of using shredded waste tires to reinforce sand. Direct shear tests were conducted on mixtures of dry sand and shredded waste tires. The following factors were studied to evaluate their influence on shear strength: normal stress, sand matrix unit weight, shred content, shred length, and shred orientation. From results of the tests, three significant factors affecting shear strength were identified: normal stress, shred content, and sand matrix unit weight. A model for estimating the strength of reinforced soils was also evaluated to determine its applicability to mixtures of sand and tire shreds. When the model is calibrated using results from one shred content, it may be useful for estimating the friction angle for other shred contents. In all cases, adding shredded tires increased the shear strength of sand, with an apparent friction angle (ϕ′) as large as 67° being obtained. Shred content and sand matrix unit weight were the most significan...

Shredded Waste Tires as a Growing Media Amendment for Production of Flowering Vinca

Catharanthus roseus plants were grown in three media, each containing one of two by-products of shredded waste tires. The media were no. 1) 1 rubber*: 1 peat moss, no. 2) 1 rubber*: 1 vermiculite: 2 peat moss, and no. 3) 2 rubber*: 1 vermiculite: 1 peat moss (by volume) where rubber* indicates either 0.6 cm shredded rubber or a fibrous by-product. Control plants were grown in 1 peatmoss: 1 rockwool and 1 vermiculite: 1 peatmoss (by volume). Catharanthus roseus cv. Peppermint Cooler plants were grown for 7 weeks in 10-cm containers at a commercial Denver-area greenhouse. Data taken included plant heights, plant widths, flowers per stem, and dry weights. Visually, plants grown in the no. 2 mix, with either fiber or 0.6-cm rubber, were similar to the controls and superior to the other two mixes. Ending plant heights were similar among the two controls and no. 2 with fiber and were taller than all other combinations. Flower numbers were greater in the 1 rockwool: 1 peat moss control and no. 2 mix with fiber than any other treatment. The same was true for stem number and dry weight. Results indicate that the no. 2 mix of 1 fiber: 1 vermiculite: 2 peatmoss has potential for container crop production.

Combustion characteristics of shredded waste tires in a fluidized bed combustor

The effects of bed temperature (700–900 °C), freeboard temperature (600–800 °C) and excess-air ratio (0–100%) on CO, NO x and SO 2 emissions, axial temperature profiles, and combustion efficiency of shredded waste tires have been determined in a 76.2 mm i.d. × 1.2m high fluidized-bed combustor. CO-emission levels are maintained below 400 ppm at freeboard temperatures above 750 °C with a 25% excess-air ratio. The freeboard temperature increases sharply at lower excess-air ratios or at bed temperatures below 750 °C. The overall combustion efficiency for waste tires is higher than for bituminous coal and increases with increasing excess-air ratio and bed temperature. The NO x concentration in the flue gas based on 6% O 2 has been correlated with the bed temperature, nitrogen fraction in the fuel and excess-air ratio.