Tire Rubber Research Articles

Shear behavior of RC beams with openings under impact loads: unveiling the effects of HSC and RECC

Incorporating transverse openings in reinforced concrete (RC) beams reduces their load-bearing capacity and stiffness, making them prone to premature failure. This highlights the need for a more nuanced understanding of their behavior to ensure structural integrity, particularly under impact loads. This research delves into a relatively unexplored area, investigating the impact performance of RC beams containing openings through numerical analysis. By comparing different concrete types, the study seeks to identify optimal materials for such applications. The concrete damage plasticity model, accounting for strain rate effects, will be employed to simulate the material behavior of normal-strength concrete (NSC), high-strength concrete (HSC), and a novel eco-friendly alternative: rubberized engineered cementitious composite (RECC). RECC incorporates recycled tire rubber as a partial substitute for traditional concrete aggregates, offering a sustainable solution while mitigating environmental hazards associated with waste tire incineration. The finite element models are validated with experimental results, accurately predicting ultimate capacities, failure modes, and post-cracking response in RC beams (with/without openings) under static/impact loads. A comprehensive parametric analysis investigates the effects of concrete strength, impact energy, impactor mass, drop height, and opening location, providing valuable insights into how these factors influence the impact behavior under drop-weight testing. The results reveal that openings in RC beams under impact loads significantly reduce strength and stiffness, with detrimental effects observed for dual shear-zone openings. Surprisingly, a small mid-span opening can enhance impact response. HSC beams exhibit lower initial displacements but higher residual values, while RECC improves overall behavior in beams with openings, reducing maximum displacement and promoting energy dissipation for improved post-impact recovery.

Tire Rubber Based Microplastic Particles Cause Adverse on Quality Parameters of Rainbow Trout Sperm Cells.

In the present study, we aimed to determine the parameters of oxidative stress markers, motility and kinematics of rainbow trout (Oncorhynchus mykiss) sperm cells exposed to different doses (0.001, 0.01, 0.1, 1.0, and 10mg/L, in vitro 4h) of tire rubber based microplastic particles (TRMP-Ps) the leachates procedure of rubber pieces. First of all, TRMP-Ps were prepared by abrasion method in accordance with the literature. Structural and morphological features of TRMP-Ps were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) methods, respectively. Energy dispersive X-ray (EDX) analysis technique was used to characterize the elemental composition of TRMP-Ps. Particle size of microplastic structures was measured hydrodynamically with dynamic light scattering analysis (DLS). After exposure, the effect of TRMP-Ps was defined by the observations of kinematics and antioxidant activities in sperm cells. Our findings showed that the straight line velocity, the curvilinear velocity, the angular path velocity, and the amplitude of lateral displacement of sperm cells decreased. Moreover, while the level of superoxide dismutase decreased dose-dependently against the toxicity of TRMP-Ps, no significant change was observed in the levels of malondialdehyde and total glutathione. The 4-h median effective concentrations (EC50) of TRMP-Ps based on mobility parameters of sperm ranged from 0.31mg/L for reduced straight line velocity of sperm cells to 0.51mg/L for reduced amplitude of lateral displacement of the spermatozoa head. Therefore, we concluded that TRMP-Ps can be a risk for the reproduction cycle of fish in aquatic environments.

Effect of Ni/tire rubber carbon as catalyst in the hydrodeoxygenation of used vegetable oil: biofuel evaluation in the reduction of atmospheric emissions

Abstract The sustainable valorization of discarded resources remains a challenge, and their requirements are crucial for long-term development. In this sense, we characterize biofuels of the diesel range obtained with used vegetable oils subjected to hydrodeoxygenation with Ni supported on tire rubber carbon obtained by the pyrolysis of waste tires. Under optimal reaction conditions, the vegetable oil conversion was 81.2 % with a selectivity of 82.3 % to C10–C18 alkanes, which is supported by the results of the catalyst characterization. A vertical direct injection engine was used to compare the behavior of the renewable biofuel and petroleum diesel blends. In comparison to petroleum diesel, the blends with renewable biofuel showed minimal power loss. In addition, the use of blends containing biofuels allowed a reduction of 25 % of CO and HC, as well as a decrease of 48 % is smoke compared to petroleum diesel, due to the fact that renewable biofuels improved evaporation after injection, reduced the density, and did not contain aromatic components.

Optimizing alkali-activated clay with rubber waste for sustainable earthen bricks: A comprehensive study

This study explores the potential of optimizing alkali-activated clay with rubber waste to create sustainable earthen bricks. The research addresses the environmental challenges associated with traditional cement-based construction materials by incorporating locally sourced calcined clay and recycled rubber tire waste. The experimental program involves testing different proportions of sand with calcined clay, varying sodium hydroxide (NaOH) concentrations, and integrating rubber content. The aim is to develop a material that balances environmental sustainability with improved mechanical and durability properties. The mechanical and microstructural properties of the resulting materials were evaluated through compressive and flexural strength tests, wetting and drying cycles, and advanced analysis techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that while the inclusion of rubber enhances certain properties such as reducing the unit weight and Structural Integrity During Wet-Dry Cycles, it adversely affects compressive and flexural strengths. This study highlights the importance of optimizing the balance between durability and mechanical strength to develop effective and sustainable construction materials.

Preparation of a rubber nanocomposite for oil/water separation using surface functionalized/silanized carbon black nanoparticles

Clean water is the basic need of living organisms on the earth. Oil spills to free waters is one of the most important threats to living beings. It has been believed that using sorbents is the most effective method for this purpose. In this research, usage of tire rubber with improved hydrophobic properties is considered. For this purpose, carbon black nanoparticles (CBNs) were surface modified with vinyltrimthoxysilane (VTMS) at concentrations of 1, 5 and 10 by sol-gel method. Before, the CBNs were hydroxylated to increase silane grafting content. The surface modified was evaluated using XPS, FTIR, TGA, BET and FESEM analysis. Results showed a great change in the CBNs nature from hydrophilic to hydrophobic after silane modification that could help in more oil absorption and water repletion at the same time. In fact, the water contact angle (WCA) of the CBNs changed from 40 to 135°. The pure and silane grafted CBNs were added to the tire tread compound to prepare elastomeric nanocomposites as oil sorbent. The results showed that the modified nanocomposite had a higher reinforcement index than the samples contained pure and hydroxylated CBNs. The effects of CBNs on WCA, OCA and oil absorption capacity of the samples were also determined. It was found that silane modification a considerable increase in the WCA from 61.2° to 125.03° and a decrease in the oil contact angle (OCA) from 70.01° to 17.74°. Also, the oil absorption capacity of rubber enhanced from 0.55 to 1.95 g/g.

Optimizing modified asphalt binder performance at high and intermediate temperatures using experimental and machine learning approaches

Asphalt pavements are highly susceptible to temperature-induced stresses, which can lead to significant deterioration such as rutting at high temperatures and cracking at low temperatures. These challenges are exacerbated by global warming, which raises pavement temperatures and potentially accelerates material degradation. Addressing these issues, this study utilizes two base asphalt binders, PG 64–22 and PG 76–22, and the use of phase change materials (PCMs) like styrene-butadiene-styrene, lignin, and ground tire rubber to enhance the resilience of asphalt binders. Through an extensive experimental investigation, which includes aging processes such as rolling thin film oven and pressure aging vessel, alongside a series of both traditional and advanced tests (including dynamic shear rheometer, rotational viscometer, Fourier transform infrared spectroscopy, among others), a comprehensive set of 51 samples were analysed. By incorporating these binders and PCMs into asphalt, the experimental work demonstrated a significant improvement in the thermal and mechanical properties, effectively increasing resistance to high-temperature rutting and fatigue cracking. Complementing the experimental approach, machine learning models were employed to predict complex asphalt binder properties, such as combustion value and failure temperature, based on the experimental data. This dual approach fills a significant gap in the literature by offering a more efficient method and prediction model for optimizing pavement materials amidst climate change, while also promising to significantly advance pavement technology by enhancing material design and performance.

Control by the curing time of the strain induced crystallization and elastocaloric properties in natural rubber and natural/waste rubber blends

This study provides a systematic investigation of the influence of the curing time on strain-induced crystallization (SIC) and elastocaloric (eC) effect in peroxide-cured natural rubber (NR) and NR/ground tyre rubber (GTR) blends. To do so, materials were prepared with three distinct curing times (t10, t50, and t90). Results reveal that extended curing times correlate with increased network hardness and elastic modulus, promoting the number of elastically active chains. GTR fillers accelerate vulcanization but reduce final network chain density due to their partially devulcanized state and their contribution to the vulcanization of the blends. Both SIC and eC effects improve with curing time, with properties at t50 closely matching those at t90, indicating an optimal crosslink density at such times. The temperature span during mechanical cycling increases linearly with curing time, largely unaffected by GTR presence. The material's coefficient of performance (COP) peaks at t50, suggesting this curing time offers the best balance between mechanical energy dissipation and temperature change, highlighting its potential for eco-friendly heating/cooling applications.

Influence of Tire Reclaimed Rubber (TRR) Loadings on Cure Characteristics and Mechanical Properties of Natural Rubber/Styrene Butadiene Rubber (NR/SBR) Blends

This investigation delves into the potential utilization of Tire Reclaimed Rubber (TRR) as a filler within Natural Rubber/Styrene Butadiene Rubber (NR/SBR) blends. TRR is obtained from discarded rubber tires and stands as a pertinent resource that necessitates its effective utilization in the production of eco-friendly, value-added rubber-based products. This is due to the rising of rubber waste tires which causes environmental concerns and all sorts of pollution. The TRR filled NR/SBR blends were fabricated using two-roll mills. The loadings of TRR were varied ranging from 20 phr to 100 phr. The aim of this study is to investigate the influence of TRR loading on the curecharacteristics and mechanical properties of blends in terms of tensile strength, rebound resilience, hardness, and density. It is found that the MH and Δ torque exhibited a decreasing trend which would indicate a reduction in crosslink density due to high loading of TRR. Meanwhile, the ts2 and tc95 increased with the increase of TRR loading. Furthermore, the tensile strength, hardness, density, and rebound resilience of blends experience a steady reduction with the incorporation of TRR. The decrement of those properties might be due to the low molecular weight of TRR. Regarding the collective findings, TRR emerges as a potentially viable candidate for waste rubber repurposing, serving as a non-reinforcing filler with optimal utility achieved at a 30 phr loading level.

Effect of high-density-polyethylene (HDPE) and waste tire rubber (WTR) on laboratory performance of styrene butadiene styrene (SBS) modified asphalt

To reduce the cost of SBS modified asphalt, we incorporated waste high-density polyethylene (HDPE) and waste tire rubber (WTR) as partial substitutes for SBS modifier. The performance parameters for HDPE, WTR, and SBS synergistic modified asphalt were designed using the response surface method. Specifically, modified asphalt groups with excellent conventional properties were identified through penetration, softening point, and ductility tests. The high/low-temperature rheological properties and anti-aging properties of the selected modified asphalt were investigated. The modification mechanism of the composite modified asphalt was studied using fluorescence microscopy (FM). Subsequently, a cost analysis of the modified asphalt was conducted. Based on the aforementioned studies, we recommend a composition of 1.5% SBS, 3% HDPE, and 10% WTR, which demonstrated superior performance compared to 4% SBS modified asphalt. Furthermore, the cost of the modified asphalt was found to be 13.3% lower than that of SBS modified asphalt.

The utilization of pulverized waste tire rubber in a soil–cement composite for sustainable compressed earth brick production

This study examined the suitability of blending waste tires with cement in indigenous soil for producing compressed earth bricks (CEB) to achieve a sustainable environment. CEB was produced with clay soil and a combination of cement at 5 and 10% levels with varying dosages of pulverized waste tire at 0, 2.5, 5, 7.5, and 10% mixture. Classification tests were conducted to determine engineering properties such as the particle size distribution, Atterberg limit, specific gravity, optimum moisture and unit weight of the soil. The physical properties of the pulverized tire were evaluated. Moreover, density, water absorption, and compressive strength were determined for hardened CEB samples produced from mixtures of soil and various proportions of blended cement and pulverized waste tire materials. The classification results showed that the soil was silty clay of low plasticity. The density of the CEB samples was observed to increase slightly with the addition of blended cement-tire residue. Furthermore, a considerable improvement in the compressive strength development of the CEB was observed; however, compared with those of the control, the peak compressive strength of the CEB samples was greater when the soil was stabilized with 7.5% pulverized waste tire material and 10% cement. A decrease in the water absorption capacity of CEB was observed with an increase in the amount of pulverized waste tire and cement in the soil mixture. The response models corroborate the experimental findings indicating that amount of waste tire rubber residue and cement had significant effects on the CEB performance. This study ensure the beneficial recycling of waste tires blended with cement in soil for making medium-strength CEB to achieve sustainable, resilient masonry construction applications.Graphical

Mechanical characteristics and structural performance of rubberized concrete: Experimental and analytical analysis

Rubberized concrete is referred to as "green concrete" by replacing fine aggregate with used tire rubber. However, although significantly increasing ductility, rubber particles lowered compressive strength. The study aimed to find the optimum ratio of crumb rubber (C-Ru) to employ in large scale elements. Firstly, the effect of C-Ru treatment and content on concrete mechanical behavior is examined. The experimental program contains 96 cubes and 78 cylinders using different percentages of untreated/treated C-Ru with portions from 5 % to 30 % replacing the sand. Then, four beams were produced with 5, 10, and 15 % sand volume substitution by C-Ru to investigate the effects of rubber content on structural performance and compared with conventional beam. It is found that C-Ru treatment has less enhancement for concrete fresh properties (workability) for using small ratios of rubber and this enhancement increases to reach 20 % for higher rubber content ratio while the comparable enhancement for hardened properties (compressive strength). In addition, well washing of the C-Ru after treatment did not affect the fresh RuC properties, while the improved the hardened properties of RuC (compressive and tensile strengths). Increasing the C-Ru content ratio decreased concrete fresh and hardened properties. Untreated C-Ru not more than 15 % as a replacement of fine aggregates is preferred to avoid large strength reductions while benefiting workability, economy, and safety. While the addition of C-Ru to the concrete mix increased the ductility, toughness, and self-weight of the beams, it also decreased their flexural capacity. Finally, the finite element analysis using ANSYS is used to compare with experimental results and thus it could accurately model behavior of rubberized concrete as a complex material that recommended for further studies.

Molecular dynamics simulation of interfacial interaction mechanisms between ground tire rubber and styrene-butadiene rubber enhanced by nanomaterial incorporation

The recycling of ground tire rubber (GTR) is an effective method for addressing black pollution. In this study, we investigated and compared the effects of acidic oxidation treatments and different nanomaterial contents on the interfacial properties of styrene-butadiene rubber (SBR) and GTR. Molecular models of GTR modified by acidic oxidation and nanomaterials, as well as SBR, were established. The interfacial interaction mechanisms between SBR and GTR were studied through tensile and shear behaviors. The results indicated that the properties of SBR-GTR interface were enhanced through acidic oxidation and nanomaterial modification, with the latter demonstrating superior advantages in augmenting the interfacial strength. Specifically, the addition of a carbon nanotube and graphene increased the interfacial cohesion strength by 55.12 % and 82.93 %, and the interfacial shear strength by 29.87 % and 43.05 %, respectively. Moreover, graphene exhibited superior performance in enhancing interfacial interactions compared to carbon nanotubes and increasing the nanomaterial content did not positively impact the improvement of interfacial properties. The interfacial properties of SBR and GTR were quantitatively analyzed using molecular dynamic (MD) simulations. This study provides a theoretical foundation for enhancing the mechanical properties of recycled rubber by using nanomaterials, thereby guiding the experimental preparation of recycled rubber.

Impact response and compression-after-impact properties of foam-core sandwich composites incorporating scrap tyre rubber particles

Integrating scrap rubber particles as fillers into polymer matrix composites offers a cost effective and environmentally sustainable pathway to manage tyre waste through the creation of value-added products. This research explores the low-velocity impact (LVI) response and compression after impact (CAI) properties of rubberised foam-core glass fibre-reinforced epoxy (GFRE) sandwich composites. Syntactic foam cores integrated with rubber particles were manufactured using vacuum-assisted resin transfer moulding (VARTM). The compression properties of rubberised foam core, vital for resisting impact damage during LVI, were examined. Results show more than 40% reduction in compression strength and modulus of the syntactic foam upon the inclusion of 33 wt.% rubber particles. The LVI response and residual compression properties of rubberised foam-core composites were also evaluated. Rubberised foam cores caused a marginal reduction in the peak impact force and led to approximately 60% reduction in the delamination area. The pre-impact compression strength was unaffected by rubber particles within the core as the GFRE face sheets carried most of the compression load. Post-impact compression strength was slightly higher in rubberised foam-core composites due to reduced delamination. Digital Image Correlation (DIC) analysis tracking of the strain evolution during CAI experiments revealed the stress-raising effect of the impact damaged region. This study showcases sustainable scrap tyre management through the inclusion of rubber particles into foam-core composites without substantially reducing in-plane compression properties before or after low-velocity impact.

Development of sustainable HPC using rubber powder and waste wire: carbon footprint analysis, mechanical and microstructural properties

This research advances the development of eco-friendly high-performance concrete (HPC) by integrating tire rubber powder and waste wire, focusing on both enhanced mechanical properties and reduced environmental impact. Substituting up to 40% of silica sand with rubber powder helps maintain the compressive strength necessary for high-strength concrete applications. The addition of waste wire is designed to improve ductility. A comprehensive evaluation includes mechanical and microstructural analyses, such as compressive, splitting tensile, and flexural strength assessments, in addition to Scanning Electron Microscopy (SEM) and Differential Thermal Analysis (DTA). Environmental implications are assessed by measuring the embodied carbon footprint. Findings indicate that the absence of rubber powder allows for a compressive strength peak of 95 MPa, while 50% rubber content leads to a decrease to 25 MPa, establishing a 40% rubber threshold for optimal strength. Conversely, 3% waste wire reinforcement enhances the strength to 106 MPa. Microstructural investigations reveal that increased rubber content adversely affects compressive strength by weakening the cement matrix, and reducing calcium-silicate-hydrate (C-S-H) formation. Significantly, the study reveals that replacing silica sand with rubber powder, along with waste wire reinforcement, substantially reduces the carbon footprint of the material, contributing to more sustainable construction methodologies.

Improving shear behavior of rubberized concrete beams through sustainable integration of waste tire steel fibers and treated rubber

This study investigates the innovative and sustainable use of crumb rubber (CR) and waste tire steel fibers (WTSF) in reinforced concrete beams. By addressing the concern of reduced shear capacity in rubberized reinforced concrete (RC) beams, the paper presents a sustainable approach that integrates WTSF and a hybrid treatment of CR involving temperature and fly ash. Six different concrete mixtures were developed, incorporating 15 % and 25 % CR as a replacement for natural fine aggregates, both with and without treatment, along with the addition of WTSF. The experimental program assessed the workability, mechanical properties, including compressive and split-tensile strength, and conducted four-point loaded flexural tests on rubberized RC beams designed to fail in shear, in order to investigate their shear behavior.A numerical study further analyzed this hybrid treatment approach across various parameters, including concrete mixture compositions, types of tensile reinforcement (conventional steel or Glass Fiber Reinforced Polymer, GFRP), transverse reinforcement types (conventional steel or GFRP), longitudinal reinforcement ratios, and the combined effects of treated rubber and WTSF. Key findings include a 10 % higher compressive strength in the 25 % treated rubberized concrete mixture (TRC25) compared to the 15 % untreated rubberized concrete (URC15). Tensile strengths were significantly enhanced, with treated rubberized concrete beams containing WTSF at 15 % and 25 % showing tensile strengths 195 % and 180 % higher than normal concrete (NC), respectively. The inclusion of treated rubber and WTSF significantly improved shear capacities, with both 15 % and 25 % rubber content mixtures demonstrating substantially higher shear capacities than normal concrete. Toughness measurements indicated that treated rubberized concrete beams with WTSF at 15 % and 25 % rubber content showed toughness levels 15 to 18 times higher than NC. Beams reinforced with GFRP showed up to a 31 % higher load capacity and greater deflection before failure compared to those with conventional steel reinforcement. The study highlights a beneficial shift from shear to flexural failure modes due to the combined effects of treated rubberized concrete and WTSF incorporation.

Characterization of wood plastic composites made with recycled waste tire rubber

Abstract Green materials are currently demanded for construction as well as other products since the 26th UN Climate Change Conference of the Parties (COP26) in 2021. Using renewable and sustainable resources to innovate new materials such as composites is encouraged. This study aimed to investigate the physical and mechanical characteristics of wood plastic composites (WPCs) when adding waste tire rubber as filler for 10% or 20% by weight. The results showed that the density of the WPC samples (50 wt% wood − 50 wt% high density polyethylene) increased with the addition of the waste tire rubber (WTR) while the dimensional stability of samples was reduced. The mechanical properties of the WPC samples were determined, including flexural strength, flexural modulus, elongation at break, tensile strength, tensile modulus, and impact strength. The WTR as filler in the WPC tended to decrease the tensile strength and flexural strength whereas it improved the impact strength of materials. The results indicated that the WTR as recycled material in WPC affected the physical and mechanical properties of the WPCs. Although the use of the WTR in the production of the WPC adversely affects the mechanical properties, the use of 10 wt% WTR was acceptable. The results of the study showed that the addition of the WTR to the WPC production process can be useful for its recycling and for reducing the cost of the WPC.

Thermomechanical-chemical devulcanization of ground tire rubber

Abstract We developed a thermomechanical devulcanization process of ground tire rubber (GTR) by incorporating chemicals to achieve better devulcanization. The samples were devulcanized in a twin-screw extruder with the help of three types of chemicals that aid devulcanization: N-(cyclohexylthio) phthalimide (PVI), dibenzamid diphenyl disulfide (DBD) and dialkyl-pentasulfide (DPS, commercialized as Aktiplast 79). We characterized the resulting devulcanizates by Soxhlet-extraction, and produced vulcanized sheets, which we characterized mechanically and examined the vulcanization process. We found that all chemicals facilitated better devulcanization and the devulcanizate had a more rubber-like behavior during mixing. Vulcanization was also slightly improved and reversion was reduced. When revulcanized, the rubber had improved strain at break and tear strength.

Novel Design of Eco-Friendly High-Performance Thermoplastic Elastomer Based on Polyurethane and Ground Tire Rubber toward Upcycling of Waste Tires.

Waste rubber tires are an area of global concern in relation to reducing the consumption of petrochemical products and environmental pollution. Herein, eco-friendly high-performance thermoplastic polyurethane (PU) elastomers were successfully in-situ synthesized through the incorporation of ground tire rubber (GTR). The excellent wet-skid resistance of PU/GTR elastomer was achieved by using mixed polycaprolactone polyols with Mn = 1000 g/mol (PCL-1K) and PCL-2K as soft segments. More importantly, an efficient solution to balance the contradiction between dynamic heat build-up and wet-skid resistance in PU/GTR elastomers was that low heat build-up was realized through the limited friction between PU molecular chains, which was achieved with the help of the network structure formed from GTR particles uniformly distributed in the PU matrix. Impressively, the tanδ at 60 °C and the DIN abrasion volume (Δrel) of the optimal PU/GTR elastomer with 59.5% of PCL-1K and 5.0% of GTR were 0.03 and 38.5 mm3, respectively, which are significantly lower than the 0.12 and 158.32 mm3 for pure PU elastomer, indicating that the PU/GTR elastomer possesses extremely low rolling resistance and excellent wear resistance. Meanwhile, the tanδ at 0 °C of the above-mentioned PU/GTR elastomer was 0.92, which is higher than the 0.80 of pure PU elastomer, evidencing the high wet-skid resistance. To some extent, the as-prepared PU/GTR elastomer has effectively solved the "magic triangle" problem in the tire industry. Moreover, this novel research will be expected to make contributions in the upcycling of waste tires.

Use of Lignin, Waste Tire Rubber, and Waste Glass for Soil Stabilization

The complex interactions between soil and additives such as lignin, glass powder, and rubber tires were investigated using principles of material and soil mechanics. Previous research has mainly focused on individual additives in clay soils. In contrast, this study investigates soil improvement with two different types of waste materials simultaneously. The improvement of soil properties by hybrid waste materials was evaluated using several laboratory tests, including the standard Proctor test, the unconfined compressive strength test, the California Bearing Ratio (CBR) test, and cyclic triaxial tests. The aim of this research is to identify key parameters for the design and construction of road pavements and to demonstrate that improving the subgrade with hybrid waste materials contributes significantly to the sustainability of road construction. The mechanical and physical properties were evaluated in detail to determine the optimal mixtures. The results show that the most effective mixture for the combination of waste glass powder and rubber tires contains 20% glass powder and 3% rubber tires, based on the dry weight of the soil. For the combination of waste glass powder and lignin, the optimum mixture consists of 15% glass powder and 15% lignin, based on the dry weight of the soil. These results provide valuable insights into the sustainable use of waste materials for soil stabilization in road construction projects.

Laboratory characterisation of sand-tyre mix as bedding material for buried structures

Bedding material directly interacts with buried structures and supports to sustain external loadings such as traffic and overburden soil pressure. Therefore, soil-structure interaction plays an essential role in the stability and safety of buried structures. In particular focusing on underground pipelines, the annual rate of failures in Australia is around 19 % per 100 km of pipeline and can cost millions of Australian dollars in maintenance. Of these annual failures, ground vibrations from heavy traffic and construction activities are a major cause. In order to reduce such effects of ground vibrations on buried structures, this paper presents the possible application of sand-rubber mixes as a bedding material, where rubber is sourced from recycled tyres. The performance of sand-tyre mixes with regard to the potential for vibration reduction is assessed through this experimental study which comprises of particle size distribution, standard proctor compaction, permeability test, direct shear test, California Bearing Ratio and Repeated Load Test. From these tests, it was found that sand mixed with up to 20 % recycled tyre rubber was the most suitable mix for use as a bedding material.