Tire Chips Research Articles

Compaction behaviour of a sandy road base contaminated with microplastics from vehicle tires

AbstractDisintegrated tire particles can easily be transferred into the road bases because of the abrasion of vehicle tires on roads. The fragmented tire particles that have a grain size of smaller than 5 mm can be expressed as microplastics. In order to simulate the tire chip microplastic concentration in a sandy road base and assess the effect of microplastics on the compaction degree of the road base, standard Proctor compaction tests were performed on 0.05%, 0.1%, 0.2%, 0.4%, 1%, 2%, 4% and 8% tire chip microplastics‐amended sandy soil by dry mass. Results showed that maximum dry unit weight (ɣdmax) of the sand increased from 16.04 to 16.99 kN/m3 as the tire chip microplastic concentration increased up to 0.4%. Further increase in the microplastic concentration resulted in a decrease in ɣdmax. Contrarily, optimum water content (wopt) decreased from 15.9 to 12.5% as a result of the tire chip microplastic addition up to a concentration of 0.4%. An additional increase in the microplastic concentration led to an increase in wopt. By considering these results, a concentration of 0.4% tire chip microplastics was found to be the optimum amount that enhanced the degree of compaction. Besides contributing to the stabilization of a sandy road base, tire chip microplastics can also be assessed in terms of environmental protection. These microplastics are forced to be stacked in the sand because of compaction. As a result, they cannot easily be transferred to water resources or agricultural products that may threaten human health and cause environmental contamination.

Behavior of group of geosynthetic encased granular piles with tire chips- aggregates mixture under static and cyclic loading – A model study

The current study addresses the dual challenges of improving the performance of soft soil beds subjected to static and cyclic stresses and managing the environmental impact of waste tire disposal. This research contributes valuable insights into the sustainable use of recycled tire chips in granular pile construction, coupled with the efficacy of combi-grid encasement for improved soft ground under static and cyclic loading conditions. A series of laboratory model tests were carried out on a group of granular piles to examine the principal parameters, such as the selection of geosynthetic materials and cyclic loading characteristics, including cyclic loading amplitude (qca) and cyclic loading frequency (f). The granular pile composition consists of (25% tire chips + 75% aggregates). The performance of granular piles on improved ground is assessed based on the settlement reduction ratio (Sc,r), accumulation of excess pore water pressure (Pexc), and stress concentration ratio (n). The key findings from static model tests are that the load-bearing capacity is significantly increased with installing a group of ordinary granular piles (= 58%) and substantially increased with combi-grid encasement (= 335%). The effectiveness of ordinary granular piles (OGP) in enhancing the performance of a soft soil bed becomes greater when subjected to lower cyclic loading frequencies (f) and smaller cyclic loading amplitudes (qca). The incorporation of combi-grid encasement greatly enhanced the cyclic performance of a group of granular piles by substantially minimizing cyclic-induced settlement (Sc) across both principle parameters f and qca. This study also examines the increased cyclic stresses on the improved soft bed, resulting in the accumulation of excess pore water pressure (Pexc) development, which is reduced to a greater extent with the help of combi-grid encasement across both principle parameters.

Mechanical properties of tire chip and cement stabilised red clay

ABSTRACT Reutilisation of waste tire chips to improve red clay is of great significance to environmental protection. The mechanical properties of tire chip and cement stabilised red clay (TCCSRC) at different proportions were investigated through compaction, compression, unconfined compression strength (UCS), and direct shear tests. The UCS and shear strength of TCCSRCs with different proportions were tested and analysed at their optimal moisture content (OMC). The results indicated that the porosity ratio, UCS, shear strength, and cohesion of TCCSRC decreased with increasing tire chip content. The addition of cement increased the sample UCS and shear strength. When the content of tire crumb is 20% and the cement content is 5%, the specimens show good performance in all basic properties, including UCS can reach 1034.3 kPa; the shear strength can reach 46.7 kPa when the axial pressure is 150 kPa.

Cyclic performance of geosynthetic-encased granular pile with tire chips and aggregates mixture in soft soil – A model study

The performance of encased granular piles subjected to heavy cyclic loading presents a significant concern in the current context. Meanwhile, global waste tire management poses a major challenge because it has a detrimental effect on the environment. To address both difficulties, this research utilizes recycled tire chips derived from end-of-life tires (ELTs) and substituting traditional aggregates in granular pile construction. This study summarizes laboratory model tests investigating the performance of geosynthetic encased granular piles designed for soft soil improvement under vertical cyclic loading. The composition of the granular pile comprised (25 % tire chips + 75 % aggregates). Various cyclic loading parameters were scrutinized, including the selection of encasement material and the best configuration for granular piles, cyclic loading frequency (f), cyclic loading amplitude (qca), length-to-diameter (L/D) ratios, granular pile end conditions, and strength of surrounding soft soil. The novel feature of this research is the evaluation of the cyclic induced settlement (Sc) – excess pore water pressure (Pexc) coupled performance for all considered factors and its effects on the encased granular piles improved soft ground under vertical cyclic loading. Key findings include ordinary granular piles (OGP) illustrated optimal performance when subjected to lower frequency and amplitude loading, smaller L/D ratios, and end bearing conditions. The provision of Combi-grid encasement notably improved the cyclic performance of granular piles by substantially reducing the cyclic induced settlement (Sc) on improved soft beds across all examined factors. This research also discusses the increased cyclic stress on the surrounding soft soil initiated excess pore water pressure (Pexc) development and is reduced to a greater extent with the help of Combi-grid encasement across all test cases.

Soft Soil Improvement with Encased Granular Piles Composed of Aggregates and Tire Chips Mixture: Experimental and Numerical Studies

Soft Soil Improvement with Encased Granular Piles Composed of Aggregates and Tire Chips Mixture: Experimental and Numerical Studies

Use of Waste Tire Chips and PET Plastic Flakes in Backfill Behind Retaining Walls

Abstract The use of waste in the field of civil engineering is one of the solutions to reduce the harmful impact of waste on the environment on the one hand and preserve natural resources on the other. This study aims to investigate the effect of using waste materials such as plastic and tire chips that can be used as backfill in retaining walls. A numerical study has been carried out by using PLAXIS 2D software version 8.6 to model three types of rigid retaining walls, namely: scale wall test, cantilever wall, and gravity wall. In addition, the backfills of those retaining walls are composed of two mixtures. The first is a mixture of sand and tire chips (TC) with different percentages (10%, 30%, 50%, and 70%). The second is a mixture of sand and PET plastic flakes at different percentages (12.5%, 22.5%, and 32.5%). The results obtained from this study confirmed that the use of PET plastic waste and tire chips waste mixed with sand in the backfills of rigid retaining walls contributes effectively to the reduction of horizontal and vertical displacements as well as the earth pressures behind the retaining walls, therefore improving the stability of the retaining walls.

The Potential Usage of Bitumen Cold Mix and Tire Chips as Stabilization Material on Clay Soil Strength Characteristics

Clay is a soil with fine particle size less than 0.002 mm, low permeability, cohession, high swelling, and slow consolidation process. Due to that problem it needs some improvement to stabilize the condition of soil before the process of construction conducted. The purpose of this study is to determine the effect of adding shredded tire and cold mix bitumen as the value of shear strength changing are cohession, friction angle, and shear strength with triaxial unconsolidated undrained test. To see the effect of those mixture, this study uses 48 soil samples with 4 variation of shredded tired (0%, 1%, 1,5%, and 2%) and 4 variation of cold mix bitumen (0%, 1%, 2%, dan 3%). The result of this study showed that the adding of shredded tired and cold mix bitumen in soil compositition can increase parameters of soil. The optimum cohession is on variation 1% SB+2% B (T99B2SB1) with the value 0.61 kg/cm2. Meanwhile the optimum value of friction angle is on variation 1.5% SB+ 1% B (T98.5B1SB1.5) with the value 7.43o. The shear strength as the sum of cohession and friction angle tends to increase with the optimum value about 0.995 kg/cm2 in variation 2% bitumen and 1% shredded tire (T99B1SB1). From the study, the adding of shredded tired and cold mix bitumen improve the shear strength. The optimum value of shear strength is on variation 2% B+1% SB (T99B1SB1) with the value 0.995 kg/cm2. This study shows that stabilization material used in this research can be an alternative material for soil stabilization.

Use of Waste Tires as Transverse Reinforcement and External Confinement in Concrete Columns Subjected to Axial Loads

Approximately 246 million waste tires are generated annually in the United States. That is roughly three tires per four individuals in the country. Most tires end up in landfills, adversely affecting the environment. In the last two decades, researchers have explored using tire chips in concrete to replace a portion of coarse aggregates. Past studies have indicated that up to 50% of coarse aggregates in concrete can be replaced with tire chips. This research proposes using recycled rubber tires and rubber chips in concrete columns. The tires are used as external transverse reinforcement in plain concrete columns. The tires function as formwork during the pour while providing confinement after curing. The concepts in this research can be used for retrofitting structures with inadequate foundations and constructing new structures. After analyzing the data from this research, the axial compressive test of confined columns was 50% greater on average than unconfined columns. The confinement effectiveness ratio for all confined specimens was greater than one.

Evaluation of Strength Behavior of Aggregates Mixed with Tire Chips in Granular Piles

Evaluation of Strength Behavior of Aggregates Mixed with Tire Chips in Granular Piles

Study of Behavior of Encased Columns Composed of Shredded Tyre Chips and Stone Aggregates in Kaolinite Clay Bed

Study of Behavior of Encased Columns Composed of Shredded Tyre Chips and Stone Aggregates in Kaolinite Clay Bed

Bond Characteristics of Deformed Steel Rebar in Palm Kernel Shell (PKS)-Rubberised Concrete Composite

The bond mechanism between concrete and steel is an important input parameter in the design of reinforced concrete elements. The reuse of waste materials as aggregates in concrete has led to the discovery of different types of concrete with unique bond characteristics. This paper reports on the bond characteristics of concrete produced from waste automobile tire chips and palm kernel shell aggregates and deformed mild steel rebars. A total of 125 concrete cubes (150 x 150 x 150mm) with metal inserts were cast from 21 concrete mixes with varied content of PKS and waste automobile tire aggregates. Pullout test was carried out to evaluate the strength of the bond mechanism between the steel and the various concrete mixes. The results revealed that bond strength decreased with increasing PKS and tire content. Moreover, increasing the bar size and embedment length reduced the bond stress. The ratio of the bond stress and compressive strength was found to be averagely 63.88%. Regarding the bond failure mechanism, it was identified that failure of the specimen occurred through either rebar pullout or tensile splitting of the concrete. Based on the results obtained, it was concluded that PKS and tire can be used as partial replacement of granite aggregates in concrete since the resultant concrete can develop adequate bond with steel bars in structural applications.

Evaluation of shear strength parameters of sustainable utilization of scrap tires derived geo-materials for civil engineering applications

The devastation caused by the illegal dumping and burning of tires has been staggering. In civil engineering, using tires engineering properties has become a major concern. For this investigation, the research used locally sourced tire chips and sand. Using tire chips sand as an alternative backfill material requires less pressure and has more improved properties than traditional backfill. Four specimens were utilized in this experiment: pure sand and sand mixtures containing 20%, 30%, and 40% tire chips, respectively. Both the Direct Shear and Triaxial Apparatus, two of the most important geotechnical tools, were used to compare and evaluate the shear properties of soil and sand tire chips. 50, 100, and 150 kPa Confining pressure and normal stress have been utilized to maintain a consistent stress level. Direct shear apparatus had a circular shape with an area of 16.62 cm2 and Triaxial shear apparatus had a height of 7.2 cm and a diameter of 3.2 cm. The stress-strain behavior of both apparatuses under ordinary loading and deviatoric stress was reported. The angles of internal friction (Φ′) and cohesion (c′) were measured for both equipment and specimens with and without tire chips, and the failure planes for direct shear and triaxial tests were reported. In both the direct and triaxial shear tests, 30% of the tire chips sand exhibit the best results, respectively. The addition of tire chips may significantly improve the toughness of the soil.

Comparative study of different materials for insulated pavement in cold regions

Pavements constructed on frost-susceptible subgrade layers are prone to deterioration from freezing in cold regions. A thermal insulation layer above the frost-susceptible subgrade layer in a pavement structure could effectively mitigate the deterioration due to frost action. The objective of study was to evaluate the thermal insulation performance of different insulating materials experimentally and numerically. Therefore, five large-scale pavement boxes, including one uninsulated pavement and four insulated pavements using different materials (i.e., XPS board, tire chips, foam glass aggregates (FGA), and foamed concrete), were constructed. The thermal insulation performance was studied under constant freezing condition and freeze-thaw cycles where the temperature profile of pavements was monitored. A finite element model was developed by considering the transient heat flow and the associated latent heat of fusion in the unbound granular layers. Correspondingly, the numerical simulation was conducted to extrapolate the temperature profile for pavement structures made by different insulating materials. The experimental results show that the XPS and FGA have the best overall insulation performance, followed by foamed concrete and tire chips. Results of the numerical simulation suggest that to achieve an equivalent level of insulation performance as a 5 cm thick XPS board under the same freezing conditions, insulating materials such as tire chips layer, FGA layer, foamed concrete layer, or recycled concrete aggregate should have insulation layer thicknesses of 40 cm, 25 cm, 30 cm, or 68 cm, respectively. In terms of cost-benefit analysis, the foamed concrete insulated pavement is the most expensive option, followed by uninsulated pavement, insulated pavements using FGA, tire chips, and XPS. This study highlights the critical role of the insulating material and the insulation layer thickness in cost-benefit thermal insulation for pavements in cold regions.

Models for Predicting Strength Reduction Factors for Concrete that Utilizes Palm Kernel Shells and Waste Automobile Tires as Aggregates

Palm kernel shells (PKS) and waste automobile tires do not only enhance the properties of concrete (e.g. damping ratio, ductility, impact resistance etc.), but also their rational utilization can significantly reduce carbon footprints and environmental pollution globally. In this study, a multivariate regression analysis was carried out to develop models for predicting the reduction factors and thereafter the strengths (compressive strength, flexural tensile strength, split tensile strength and bond strength) of concrete that utilizes PKS and waste automobile tire chips as partial to full replacement of the conventional crushed granite stones as coarse aggregates. The strength reduction factors, , were modelled as a function of the total aggregate replacement level (TAR), and the volume of PKS (P) and tire (T) particles in a given concrete mix whilst the performance of the models was assessed using the Mean Squared Error (MSE) and the Coefficient of Determination () techniques. After studying several mathematical functions, it was found that a single linear regression model can be used to predict the strength reduction factors for all the mechanical properties of the concrete tested but with different function parameters. The values of the ranged from 0 to 1 depending on the aforementioned factors. However, a of 0.53 (53%) can be achieved at the 50% optimum replacement where P50T50 for any of the mechanical properties. Furthermore, for each of the concrete properties, the was positively correlated with the volume of PKS but negatively correlated with the TAR level and volume of tire particles in the concrete matrix. Thus, an increase in the TAR level or tire content decreases the and vice versa. In conclusion, the proposed models can be used to establish the target strengths of PKS.

Sand Rubber Mixtures under Oedometric Loading: Sand-like vs. Rubber-like Behavior

Each year, the number of scrap tires disposed of in huge piles across the world continuously increases. Consequently, new recycling solutions for these materials have to be proposed. Among them, one possibility consists of shredding tires and mixing the obtained tire chips with sand, which can be used as alternative soils in various geotechnical applications, such as backfilling for retaining structures, slope and highway embankment stabilization, road constructions, soil erosion prevention, and seismic isolation of foundations. Such types of mixtures are highly heterogeneous due to the important difference in elasticity and deformability between the two constituents, which leads to complex mechanical behavior. In this article, the one-dimensional loading/unloading behavior of sand-rubber mixtures is investigated by laboratory strain-controlled experiments performed for different packing densities, particle sizes, rubber contents, and sand/rubber size ratios. After a global analysis of the increase of the packing deformation with the rubber fraction and the stress level, a novel criterion to classify the behavior of the mixture as sand-like or rubber-like was proposed, based on the concavity of the void ratio—log of vertical stress curve. The concavity increased with the stress level and the rubber fraction, up to the limits where the saturation of the voids due to their filling with rubber induces a rubber-like behavior. A simplified phase diagram, limited to the range of this study, is proposed. The one-dimensional confined stiffness and the swelling behavior were also analyzed.

The Effect of Using Waste Automobile Tires and Palm Kernel Shells as Coarse Aggregates in Concrete on Tensile Strength and Failure Modes

The use of waste materials as aggregates in concrete is hailed by many as a huge step towards addressing the overreliance on granite stones as aggregate in concrete. It also offers a strategic eco-friendly means of disposing these wastes to minimize their impacts on the environment. This study assessed the tensile strength and modes of failure of concrete that utilizes waste automobile tire chips and palm kernel shells (PKS) as partial to full replacement of the conventional crushed granite stones as coarse aggregates in concrete. Portland cement concrete with the mix ratio: 1: 1.5: 2.5 (cement: sand: granite coarse aggregate) based on the mass of the constitient materials was prepared as control from which twenty additional mixes were generated by replacing portions of the granite stones with PKS and tire aggregates while the sand and w/c ratio were kept constant. A total of 105 cylindrical specimens (150 x 300mm) and 155 beams (100 × 100 × 500 mm) were cast to evaluate the split tensile () and flexural tensile () strengths of the concrete mixes at 7, 14, 21, 28, 56 and 90 days of curing while observing their modes of failure. The results showed that, there is systematic decrease in the tensile strengths of the concrete with increase in the volume of tire and PKS particles. However, up to 50% replacement level, adequate tensile strength can be achieved for structural purposes. At this replacement level, the mix with P50T50 recorded of 3.10 N/mm2, representing 59% of the control mix. From the failure patterns observed, the mixes with high volume of tire exhibited ductile failure mode; thus giving ample warning before the ultimate failure while the PKS concrete’s failure were more brittle and explosive. In conclusion, a blend of PKS and tire as aggregates in concrete is recommended especially for structures subjected to sudden loadings such as those located in earthquake zones.

Assessing Compressive Strength of Concrete with Waste Automobile Tire and Palm Kernel shells as Aggregates

All throughout the world, millions of end-of-service life automobile tires and Palm Kernel Shells (PKS) are generated as waste that require proper disposal. The reuse of these wastes in concrete is regarded as a novel approach that has environmental, health and performance related benefits. On this basis, the current study was designed to investigate the coupled effect of using both PKS and tire chips as aggregates in concrete mixes on the compressive strength and other properties of concrete. A total of twenty-one (21) concrete mixes containing different volumes of PKS and tire chips as a partial to full replacement of the conventional crushed granite aggregates were prepared to evaluate their impact on the fresh (i.e. slump) and hardened (i.e. density and compressive strength) properties of the concrete at 7, 14, 21, 28, 56 and 90days of curing. The results showed that there is a systematic decrease in compressive strength, workability and density of concrete with increase in tire (T) and PKS (P) content. However, up to 50% total aggregate replacement (TAR) level, adequate compressive strength can be achieved for structural purposes. At this optimum point, the mix with P75T25 recorded a compressive strength of 13.27 N/mm2 which represents about 44% of the strength of the control mix. Generally, the inclusion of PKS aggregates improves compressive strength and decrease the rate of strength reduction.

Numerical Study on the Reduction of Dynamic Lateral Earth Pressure on Retaining Wall using Waste Tyre

The performance of retaining under various loading circumstances is dependent on the kind of backfills employed; nonetheless, several lightweight fill materials such as EPS geofoam, geoboard, fly ash, waste tyre (in various forms), and so on are widely utilised as backfill materials. The key benefits of adopting lightweight materials are a lower overall lateral force on the wall and lateral displacement of the retaining wall. Because of the growing number of automobiles, disposing of discarded tyres has become a major issue. Waste tyres are increasingly being utilised in geotechnical applications such as embankment fill, retaining walls, machine foundations, and bridge abutments. According to prior research, shredded tyre inclusion with soil is employed as backfill material for earth-retaining constructions.The most important aspect of sectional design for retaining walls is the total lateral thrust. Literature indicates that the use of waste tyres in backfill decreases the overall lateral thrust whether used as sole backfill as tyre chips or a mixture of sand tyres or when used as a compressible inclusion between the wall and the backfill.In the present work, a numerical simulation was conducted using OPTUM G2 (a computational tool based on finite elements) to examine the effect of discarded tyres as backfill material on the total lateral earth pressure for an 8-meter-high wall. Maximum surcharge pressure of 20 kPa is applied to the backfilling.The use of discarded tyres as a backfill material significantly decreases total lateral earth pressure on the wall by 50-54% compared to walls backfilled with soil, according to the current study.

Durability Study of Rubberized Lightweight Concrete Using Nano-Silica

Lightweight concrete (LWC) is used in the construction of partition and panel walls in framed structures because it reduces the dead load acting on the structure. Rubberized lightweight aggregate concrete is made by using waste rubber tyre chips as a partial replacement of coarse aggregate which increases the ductility, and toughness and minimizes the impact effect of concrete. The presence of rubber content decreases the compressive strength and bond strength, which affects the durability of concrete. Nowadays, nanomaterials' application has received much attention to enhance concrete properties. Due to the nano-filler effect and the pozzolanic reaction, the microstructure becomes more homogeneous and less porous, especially at the interfacial transition zone (ITZ), which leads to reduced permeability. Among the nano-materials, nano-silica has gained particular attention compared to conventional mineral addition due to its better performance in concrete. Incorporating a small number of nanoparticles in concrete can modify the nano-structure of cementitious materials, thus producing high strength and durability. This study is to investigate the durability properties of rubberized LWC containing nano-silica at dosages of 1%, 3%, and 5% by replacement of cement, respectively. Durability under a marine environment is to be analysed based on compressive strength, bond strength, and resistance to the penetration of chloride ions for 28 and 56 days.

Discrete element analysis of sand-tyre chips mixtures with different tyre chip orientations under triaxial compression tests

Sand-tyre chips (STCh) mixtures are emerging civil engineering materials that have been widely studied and applied. In the sand-tyre chips system, the mechanical behavior of sand matrix is improved attributed to the excellent property of tyres. However, the effect of tyre chip orientation for STCh mixtures is not fully appreciated, especially from the microscopic scale. In this paper, the microscopic behaviors of STCh mixtures with different orientation tyre chips were investigated employing the Discrete Element Method (DEM). The tyre chips model was constructed with sufficient consideration and the microscopic parameters of STCh model were confirmed by the calibration procedure. Simulation results illustrate that horizontal tyre chips more effectively enhance the mechanical properties of mixtures. The visualization of the specimen shows that the orientation of tyre chips can influence the evolution of system contact network, formation of shear band, and bulging deformation of specimen. The microscopic mechanism including the composition of strong contacts, coordination number, average normal contact force, sliding and rolling, energy storage and dissipation, and the tensile force in tyre chips were studied to evaluate the discrepancies of different orientation tyre chips. The mechanism of the reinforcement for tyre chips can receive further understanding from this study.