Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature...Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.展开更多
The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building fou...The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.展开更多
Applying the results of stress and strain calculated by 3D finite element model of truck radial tire 11.00R20, a MATLAB program used to compute rolling resistance of the tire caused by hysteresis rolling resistance (H...Applying the results of stress and strain calculated by 3D finite element model of truck radial tire 11.00R20, a MATLAB program used to compute rolling resistance of the tire caused by hysteresis rolling resistance (HRR) is worked out. The HRR distribution on different part of tire section, and the effects of speed, load, internal pressure and the width of the rim on HRR are analyzed. The analysis results showed that energy loss produced by tread rubber contributes the most part to HRR of the whole tire, and that to decrease the HRR, the hysteresis factor of the tread rubber should be reduced, and the distribution of the stress and strain on the section be optimized.展开更多
The main chemical composition of pyrolysis carbon black of waste tires is C,O,Cu,Zn and so on.The content of ash and fine powder in pyrolysis carbon black is high,and the 300%elongation stress is high.The difference b...The main chemical composition of pyrolysis carbon black of waste tires is C,O,Cu,Zn and so on.The content of ash and fine powder in pyrolysis carbon black is high,and the 300%elongation stress is high.The difference between pyrolysis carbon black and furnace black N326,which is commonly used in rubber,is obvious compared with chemical property.The pyrolysis carbon black was used to replace furnace black N326 in the transition layer of all steel load Radial tire rubber through experimental study.It was found that the compression heat generation and dynamic loss(Tanδ)of the blend rubber before and after aging were obviously reduced,the elongation at break and resilience increased,while the tensile stress and tear strength decreased by 100%and 300%,but the hardness and tensile strength changed little before and after aging.According to the latest raw material price calculation,15 used tire pyrolysis carbon black instead of furnace carbon black N326 used in all steel Radial tire transition layer rubber application,excluding labor costs,electricity and equipment depreciation,a ton of blended rubber saves about$22.86 in production costs.展开更多
For a long time and until now, rubber is the most used material for the manufacture of tires for motor vehicles. Unfortunately, once the tire meets its life cycle, the remaining rubber cannot be recycled, so the tires...For a long time and until now, rubber is the most used material for the manufacture of tires for motor vehicles. Unfortunately, once the tire meets its life cycle, the remaining rubber cannot be recycled, so the tires are discarded in collection centers and often in clandestine dumps. This represents a serious environmental problem because, in one case, these waste tires become breeding grounds for insects and wildlife that is harmful to humans. In the second case, the tires are burned, releasing highly damaging gases into the atmosphere. On the other hand, concrete is worldwide the construction material par excellence. It is basically composed of cement, gravel and sand. Mixing these three components in different proportions, their mechanical strength in compression can be increased. However, due to its fragile nature, concrete, once a crack is formed, it rapidly advances by fragmenting the material and producing its rapid collapse. In the present work, in order contribute to the care of the environment as well as to modify the fracture mode of the concrete, rubber particles obtained from waste tires were used as sand substitute in hydraulic concrete. In addition, rubber modified samples concrete were lately exposed to 70 kGy of gamma radiation in order to study the effects of this radiation on the mechanical deformation of concrete. The results showed a decrease in the mechanical properties of the concrete with rubber particles with respect to the traditional concrete itself. However, such decreases were offset by the fact that samples with rubber addition do not collapses as fast as the free rubber samples. The acquired data pave the way for research with great benefits, such as the use of recycled tires in concrete for its fracture mode modification in a beneficial way, as well as a possible decrease in the cost of concrete.展开更多
Environmental problems caused by waste tires are becoming increasingly prominent.There is an urgent need to find a green way to dispose of waste tires,and scholars have made considerable efforts in this regard.In the ...Environmental problems caused by waste tires are becoming increasingly prominent.There is an urgent need to find a green way to dispose of waste tires,and scholars have made considerable efforts in this regard.In the construction industry,rubber extracted from waste tires can be added to concrete to alleviate environmental problems to a certain extent.As a new building material,rubber concrete has superior properties compared to ordinary concrete and has been widely used in many fields.Numerous studies have been conducted worldwide to investigate the effect of waste tire rubber on the performance of concrete.It has been reported that the addition of waste tire rubber has a significant influence on the performance of concrete.Workability influences the hardened performance of rubber concrete,especially the durability.Based on the current research results,the workability and durability of concrete manufactured with waste tire rubber,including water absorption and permeability,carbonation resistance,chloride ion permeability resistance,and freeze-thaw resistance,are summarized in this paper.It is concluded that the addition of waste tires has a negative effect on the workability of concrete.In terms of durability,concrete exhibits better chloride ion penetration resistance and frost resistance,with a higher water absorption rate,and lower anti-permeability and carbonation resistance owing to the addition of waste tire rubber.展开更多
There are different types of pollutants that are harmful to the environment, including smog, chemicals that are dumped into rivers, scrap tires, etc. The latter have the particularity that it is not possible to recycl...There are different types of pollutants that are harmful to the environment, including smog, chemicals that are dumped into rivers, scrap tires, etc. The latter have the particularity that it is not possible to recycle them to manufacture new tires. In the present work, hydraulic concrete plates added with waste tire rubber were manufactured to modify their sound absorption capacity. It was found that the rubber additions produce changes in the density of the material and in the sound absorption capacity. When the material is exposed to high-frequency sounds that correspond to high-pitched sounds, its absorption capacity increases. On the contrary, when the test frequency is low, that is, bass sounds, the sound absorption capacity decreases. The results obtained in this work suggest that the proposed mixtures are suitable for the possible manufacture of acoustic insulating shields.展开更多
Large amounts of used rubber tires are discarded annually. A long time is needed for them to degrade naturally. This poses two major problems: environmental pollution and wastage of valuable rubber. On the other hand,...Large amounts of used rubber tires are discarded annually. A long time is needed for them to degrade naturally. This poses two major problems: environmental pollution and wastage of valuable rubber. On the other hand, with the harm of vibration and noise widely recognized, desires to control them intensify. As an important means of vibration control, viscoelastic damping technology has advanced greatly. The need for cheap and high quality viscoelastic damping materials increases rapidly. This paper made a trial to use ground rubber tire (GRT) recovered from old tires to make damping materials. The GRT is treated specially first. Then it was pressed into slabs and vulcanized. Finally, the product was cut into test samples. An Oberst beam was used to determine the loss factor βand storage modulus E. Results show that the damping materials exhibit good damping α-bility.展开更多
Recycling end-of-life tire rubber as asphalt modifier is known as a sustainable paving technology with merits including enhanced pavement durability,waste tire consumption and noise reduction.However,the criticisms on...Recycling end-of-life tire rubber as asphalt modifier is known as a sustainable paving technology with merits including enhanced pavement durability,waste tire consumption and noise reduction.However,the criticisms on the high construction emissions of asphalt rubber(AR)have limited its application.Warm mix asphalt(WMA)effectively reduces the mixing and compaction temperatures of conventional hot mix asphalt mixtures.The combination of AR and WMA,called warm asphalt rubber(WAR),is a promising paving material which achieves pavement sustainability from principles to practices.Many studies have demonstrated that WMA technologies work effectively with AR pavement in different ways,alleviating the concerns of potential higher emissions of AR by decreasing mixing and paving temperatures.A comprehensive literature review about WAR brings a better understanding of this promising paving technology.The findings of 165 publications were summarized in this review.It summarized the recent developments of WAR in various aspects,including rheological properties,mix design,mixture mechanical performance,field application,construction emission,and asphalt-rubber-WMA additive interaction.It is expected that this review is able to provide extensive information to explore further research development and application of WAR.展开更多
This experimental work investigates the impact of substituting part of the conventional aggregates with rubber aggregates on certain characteristics of the cement concretes. This incorporation of rubber aggregates res...This experimental work investigates the impact of substituting part of the conventional aggregates with rubber aggregates on certain characteristics of the cement concretes. This incorporation of rubber aggregates resulting from cutting worn tires in practical sizes decreases the mechanical resistances of the concretes while improving slightly the fluidity of the tested mixtures. The effect of these aggregates on the shrinkage of the concretes at an early age is appreciable and even very interesting for the concretes used, for example, in road construction. This technique of cutting worn tires without any further treatment makes it accessible to everyone which helps not only in saving the environment by getting rid of this cumbersome waste but also in saving traditional aggregates.展开更多
Scrapped tires from vehicles are produced in large quantities. Despite numerous existing uses of scrapped tires, alarge quantity ends up at the landfill sites, which contributes to environmental degradation. The devel...Scrapped tires from vehicles are produced in large quantities. Despite numerous existing uses of scrapped tires, alarge quantity ends up at the landfill sites, which contributes to environmental degradation. The development ofmore applications of scrapped tire usage can reduce the disposal of tires at landfill sites. This research proposes anovel use of scrapped tires by using the strips taken from scrapped tires in replacement of steel bars as reinforcement. Manhole covers were produced using scrapped tires by completely replacing the steel with scrapped tires.Four different samples of manhole covers were prepared and tested. The highest bearing capacity of 25.5 kN wasrecorded with a sample of 100 mm thickness made with cementitious composite, which is 2.25 times higher thanthe bearing capacity of a conventional reinforced-concrete manhole cover. The use of manhole covers made withscrapped tires can effectively address the theft issue of manhole covers. The lifecycle cost analysis shows that themanhole cover made with scrapped tires is 3.4 times more cost-effective in comparison with the conventionalmanhole cover. This research shows a new avenue of the potential use of scrapped tires as reinforcement in structures, which can improve sustainable construction practices.展开更多
The friction of road surface covered by snow or ice is very low and that results in reducing vehicle traction forces and potential traffic accidents. In general, to establish a master curve on a rubber-ice friction mo...The friction of road surface covered by snow or ice is very low and that results in reducing vehicle traction forces and potential traffic accidents. In general, to establish a master curve on a rubber-ice friction model is difficult because the ice surface, being not far removed from its melting point, reacts itself very sen-sitively to pressure, speed, and temperature changes. In this paper, an accepta-ble frictional interaction model was implemented to finite element method to rationally examine the frictional interaction behavior on ice between the tire and the road surface. The formula of friction characteristic according to tem-perature and sliding velocity on the ice surface was applied for tire traction analysis. Numerical results were verified by comparing the outdoor test data and it was confirmed to indicate similar correlation. It is found that the rub-ber-ice friction model will be useful for the improvement of the ice traction performance of tire.展开更多
In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migr...In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.展开更多
The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used t...The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used to improve the asphalt concrete properties. Raw materials used were prepared and tested. Varies of asphalt concrete mixtures were prepared with different ratios of bitumen (5, 5.5, 6, 6.5, 7% % of concrete weight). The Marshall mix design method was used to determine optimum conditions for bitumen in asphalt concrete with specific weight, stability and flow Test, the optimum amount of bitumen was 6.1% of whole asphalt concrete. The different percentages of waste tire rubber powder (0.0, 0.05, 0.10, 0.15% of bitumen weight) were added in optimum bitumen of asphalt concretes, then specific weight and Marshall test were evaluated. These asphalt-rubber mixtures were found to act quite differently from traditional, unmodified asphalt mixtures. However, these results indicate that improved pavement performance can be achieved with asphalt-rubber binder.展开更多
Mechanochemically partially devulcanized ground rubber tire (GRT) was revulcanized in composition with virgin styrene butadiene rubber (SBR). Reclaiming of GRT was carried out by tetra methyl thiuram disulfide (TMTD) ...Mechanochemically partially devulcanized ground rubber tire (GRT) was revulcanized in composition with virgin styrene butadiene rubber (SBR). Reclaiming of GRT was carried out by tetra methyl thiuram disulfide (TMTD) in presence of spindle oil. The cure characteristics and tensile properties of SBR compounds were investigated. Results indicate that the minimum torque and Mooney viscosity of the SBR compounds increase with increasing reclaim rubber (RR) loading whereas the scorch time remain unaltered but optimum cure time exhibit a decreasing trend. Increasing RR loading also gives SBR compounds better resistance towards swelling but the 100% modulus, 200% modulus tensile strength, and the elongation at break increases. Thermogravimetric analysis of SBR/RR vulcanizates was carried out in order to get thermal stability of the vulcanizates. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the SBR/RR vulcanizates.展开更多
Thermoplastic elastomeric blends prepared from blending of (10%, 20%, 30%, 40% and 50 wt%) high density polyethylene(HDPE) and (10%, 20%, 30%, 40% and 50 wt%) ground rubber tire (TPV-R). The blends prepared contain (H...Thermoplastic elastomeric blends prepared from blending of (10%, 20%, 30%, 40% and 50 wt%) high density polyethylene(HDPE) and (10%, 20%, 30%, 40% and 50 wt%) ground rubber tire (TPV-R). The blends prepared contain (HDPE)/polybutadiene (TPV-V). The two blends were successfully prepared through a dynamic vulcanization process, involving dicumyl peroxide (3%) as vulcanizing agent. The data of the mechanical (tensile strength at yield, %elongation and young modulus) and rheological properties (shear stress, shear rate, viscosity, flow behavior index and activation energy of melt flow) of the TPV-V and TPV-R showed that there was comparable results between the two blends.展开更多
The presence of waste tires poses an environmental challenge as they occupy a significant amount of land and are expensive to dispose in landfills.However,reusing waste tires can address this issue when waste tires ar...The presence of waste tires poses an environmental challenge as they occupy a significant amount of land and are expensive to dispose in landfills.However,reusing waste tires can address this issue when waste tires are used in geotechnical applications.To determine the viability of this approach,laboratoryscale tests were conducted to investigate load-bearing capacity of circular footings on sand-tire shred(STS)mixtures with shredded waste tire contents of 5%e15%by weight and three different widths of shreds.The investigation focused on analyzing the thickness of layers composed of STS mixtures,the soil cap,and the impact of geogrids on bearing capacity.The results indicate that a specific mixture of sand and tire shreds provides the highest footing-bearing capacity.In addition,the optimal shred content and size were found to be 10%by weight and 2 cm×10 cm,respectively.Furthermore,for a given tire shred width,a particular length provides the largest bearing capacity.The results agree well with that of previous research conducted by the first author and his colleagues in direct shear and California bearing ratio(CBR)tests.The primary finding of this research is that the use of two-layered STS mixtures reinforced by geogrids significantly enhances the bearing capacity.展开更多
Pneumatic tire modeling and validation have been the topic of several research papers, however, most of these papers only deal with pneumatic passenger and truck tires. In recent years, wheeled-scaled vehicles have ga...Pneumatic tire modeling and validation have been the topic of several research papers, however, most of these papers only deal with pneumatic passenger and truck tires. In recent years, wheeled-scaled vehicles have gained lots of attention as a feasible testing platform, nonetheless up to the authors’ knowledge there has been no research regarding the use of scaled tires and their effect on the overall vehicle performance characteristics. This paper presents a novel scaled electric combat vehicle tire model and validation technique. The pro-line lockdown tire size 3.00 × 7.35 is modeled using the Finite Element Analysis (FEA) technique and several materials including layered membrane, beam elements, and Mooney-Rivlin for rubber. The tire-rim assembly is then described, and the rigid body analysis is presented. The tire is then validated using an in-house custom-made static tire testing machine. The tire test rig is made specifically to test the pro-line tire model and is designed and manufactured in the laboratory. The tire is validated using vertical stiffness and footprint tests in the static domain at different operating conditions including several vertical loads. Then the tire is used to perform rolling resistance and steering analysis including the rolling resistance coefficient and the cornering stiffness. The analysis is performed at different operating conditions including longitudinal speeds of 5, 10, and 15 km/h. This tire model will be further used to determine the tractive and braking performance of the tire. Furthermore, the tire test rig will also be modified to perform cornering stiffness tests.展开更多
Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resista...Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.展开更多
文摘Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.
基金funding by Bhabha Atomic Research Centre (BARC),Mumbai
文摘The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.
文摘Applying the results of stress and strain calculated by 3D finite element model of truck radial tire 11.00R20, a MATLAB program used to compute rolling resistance of the tire caused by hysteresis rolling resistance (HRR) is worked out. The HRR distribution on different part of tire section, and the effects of speed, load, internal pressure and the width of the rim on HRR are analyzed. The analysis results showed that energy loss produced by tread rubber contributes the most part to HRR of the whole tire, and that to decrease the HRR, the hysteresis factor of the tread rubber should be reduced, and the distribution of the stress and strain on the section be optimized.
文摘The main chemical composition of pyrolysis carbon black of waste tires is C,O,Cu,Zn and so on.The content of ash and fine powder in pyrolysis carbon black is high,and the 300%elongation stress is high.The difference between pyrolysis carbon black and furnace black N326,which is commonly used in rubber,is obvious compared with chemical property.The pyrolysis carbon black was used to replace furnace black N326 in the transition layer of all steel load Radial tire rubber through experimental study.It was found that the compression heat generation and dynamic loss(Tanδ)of the blend rubber before and after aging were obviously reduced,the elongation at break and resilience increased,while the tensile stress and tear strength decreased by 100%and 300%,but the hardness and tensile strength changed little before and after aging.According to the latest raw material price calculation,15 used tire pyrolysis carbon black instead of furnace carbon black N326 used in all steel Radial tire transition layer rubber application,excluding labor costs,electricity and equipment depreciation,a ton of blended rubber saves about$22.86 in production costs.
文摘For a long time and until now, rubber is the most used material for the manufacture of tires for motor vehicles. Unfortunately, once the tire meets its life cycle, the remaining rubber cannot be recycled, so the tires are discarded in collection centers and often in clandestine dumps. This represents a serious environmental problem because, in one case, these waste tires become breeding grounds for insects and wildlife that is harmful to humans. In the second case, the tires are burned, releasing highly damaging gases into the atmosphere. On the other hand, concrete is worldwide the construction material par excellence. It is basically composed of cement, gravel and sand. Mixing these three components in different proportions, their mechanical strength in compression can be increased. However, due to its fragile nature, concrete, once a crack is formed, it rapidly advances by fragmenting the material and producing its rapid collapse. In the present work, in order contribute to the care of the environment as well as to modify the fracture mode of the concrete, rubber particles obtained from waste tires were used as sand substitute in hydraulic concrete. In addition, rubber modified samples concrete were lately exposed to 70 kGy of gamma radiation in order to study the effects of this radiation on the mechanical deformation of concrete. The results showed a decrease in the mechanical properties of the concrete with rubber particles with respect to the traditional concrete itself. However, such decreases were offset by the fact that samples with rubber addition do not collapses as fast as the free rubber samples. The acquired data pave the way for research with great benefits, such as the use of recycled tires in concrete for its fracture mode modification in a beneficial way, as well as a possible decrease in the cost of concrete.
基金supported by the financial support received from Program for Innovative Research Team(in Science and Technology)in University of Henan Province of China(Grant No.20IRTSTHN009)National Natural Science Foundation of China(Grant Nos.U2040224,52179145)Natural Science Foundation of Henan(Grant Nos.212300410018,222300420081).
文摘Environmental problems caused by waste tires are becoming increasingly prominent.There is an urgent need to find a green way to dispose of waste tires,and scholars have made considerable efforts in this regard.In the construction industry,rubber extracted from waste tires can be added to concrete to alleviate environmental problems to a certain extent.As a new building material,rubber concrete has superior properties compared to ordinary concrete and has been widely used in many fields.Numerous studies have been conducted worldwide to investigate the effect of waste tire rubber on the performance of concrete.It has been reported that the addition of waste tire rubber has a significant influence on the performance of concrete.Workability influences the hardened performance of rubber concrete,especially the durability.Based on the current research results,the workability and durability of concrete manufactured with waste tire rubber,including water absorption and permeability,carbonation resistance,chloride ion permeability resistance,and freeze-thaw resistance,are summarized in this paper.It is concluded that the addition of waste tires has a negative effect on the workability of concrete.In terms of durability,concrete exhibits better chloride ion penetration resistance and frost resistance,with a higher water absorption rate,and lower anti-permeability and carbonation resistance owing to the addition of waste tire rubber.
文摘There are different types of pollutants that are harmful to the environment, including smog, chemicals that are dumped into rivers, scrap tires, etc. The latter have the particularity that it is not possible to recycle them to manufacture new tires. In the present work, hydraulic concrete plates added with waste tire rubber were manufactured to modify their sound absorption capacity. It was found that the rubber additions produce changes in the density of the material and in the sound absorption capacity. When the material is exposed to high-frequency sounds that correspond to high-pitched sounds, its absorption capacity increases. On the contrary, when the test frequency is low, that is, bass sounds, the sound absorption capacity decreases. The results obtained in this work suggest that the proposed mixtures are suitable for the possible manufacture of acoustic insulating shields.
文摘Large amounts of used rubber tires are discarded annually. A long time is needed for them to degrade naturally. This poses two major problems: environmental pollution and wastage of valuable rubber. On the other hand, with the harm of vibration and noise widely recognized, desires to control them intensify. As an important means of vibration control, viscoelastic damping technology has advanced greatly. The need for cheap and high quality viscoelastic damping materials increases rapidly. This paper made a trial to use ground rubber tire (GRT) recovered from old tires to make damping materials. The GRT is treated specially first. Then it was pressed into slabs and vulcanized. Finally, the product was cut into test samples. An Oberst beam was used to determine the loss factor βand storage modulus E. Results show that the damping materials exhibit good damping α-bility.
基金Project(51808228)supported by the National Natural Science Foundation of ChinaProject(OE514/10-1)supported by the German Research Foundation。
文摘Recycling end-of-life tire rubber as asphalt modifier is known as a sustainable paving technology with merits including enhanced pavement durability,waste tire consumption and noise reduction.However,the criticisms on the high construction emissions of asphalt rubber(AR)have limited its application.Warm mix asphalt(WMA)effectively reduces the mixing and compaction temperatures of conventional hot mix asphalt mixtures.The combination of AR and WMA,called warm asphalt rubber(WAR),is a promising paving material which achieves pavement sustainability from principles to practices.Many studies have demonstrated that WMA technologies work effectively with AR pavement in different ways,alleviating the concerns of potential higher emissions of AR by decreasing mixing and paving temperatures.A comprehensive literature review about WAR brings a better understanding of this promising paving technology.The findings of 165 publications were summarized in this review.It summarized the recent developments of WAR in various aspects,including rheological properties,mix design,mixture mechanical performance,field application,construction emission,and asphalt-rubber-WMA additive interaction.It is expected that this review is able to provide extensive information to explore further research development and application of WAR.
文摘This experimental work investigates the impact of substituting part of the conventional aggregates with rubber aggregates on certain characteristics of the cement concretes. This incorporation of rubber aggregates resulting from cutting worn tires in practical sizes decreases the mechanical resistances of the concretes while improving slightly the fluidity of the tested mixtures. The effect of these aggregates on the shrinkage of the concretes at an early age is appreciable and even very interesting for the concretes used, for example, in road construction. This technique of cutting worn tires without any further treatment makes it accessible to everyone which helps not only in saving the environment by getting rid of this cumbersome waste but also in saving traditional aggregates.
文摘Scrapped tires from vehicles are produced in large quantities. Despite numerous existing uses of scrapped tires, alarge quantity ends up at the landfill sites, which contributes to environmental degradation. The development ofmore applications of scrapped tire usage can reduce the disposal of tires at landfill sites. This research proposes anovel use of scrapped tires by using the strips taken from scrapped tires in replacement of steel bars as reinforcement. Manhole covers were produced using scrapped tires by completely replacing the steel with scrapped tires.Four different samples of manhole covers were prepared and tested. The highest bearing capacity of 25.5 kN wasrecorded with a sample of 100 mm thickness made with cementitious composite, which is 2.25 times higher thanthe bearing capacity of a conventional reinforced-concrete manhole cover. The use of manhole covers made withscrapped tires can effectively address the theft issue of manhole covers. The lifecycle cost analysis shows that themanhole cover made with scrapped tires is 3.4 times more cost-effective in comparison with the conventionalmanhole cover. This research shows a new avenue of the potential use of scrapped tires as reinforcement in structures, which can improve sustainable construction practices.
文摘The friction of road surface covered by snow or ice is very low and that results in reducing vehicle traction forces and potential traffic accidents. In general, to establish a master curve on a rubber-ice friction model is difficult because the ice surface, being not far removed from its melting point, reacts itself very sen-sitively to pressure, speed, and temperature changes. In this paper, an accepta-ble frictional interaction model was implemented to finite element method to rationally examine the frictional interaction behavior on ice between the tire and the road surface. The formula of friction characteristic according to tem-perature and sliding velocity on the ice surface was applied for tire traction analysis. Numerical results were verified by comparing the outdoor test data and it was confirmed to indicate similar correlation. It is found that the rub-ber-ice friction model will be useful for the improvement of the ice traction performance of tire.
文摘In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.
文摘The research considered urgent ecological reasons linked to environment such as worn tires, the waste tire rubber's powder was collected from the tire cars repair shops (passed from the sieve No 18 μm), and used to improve the asphalt concrete properties. Raw materials used were prepared and tested. Varies of asphalt concrete mixtures were prepared with different ratios of bitumen (5, 5.5, 6, 6.5, 7% % of concrete weight). The Marshall mix design method was used to determine optimum conditions for bitumen in asphalt concrete with specific weight, stability and flow Test, the optimum amount of bitumen was 6.1% of whole asphalt concrete. The different percentages of waste tire rubber powder (0.0, 0.05, 0.10, 0.15% of bitumen weight) were added in optimum bitumen of asphalt concretes, then specific weight and Marshall test were evaluated. These asphalt-rubber mixtures were found to act quite differently from traditional, unmodified asphalt mixtures. However, these results indicate that improved pavement performance can be achieved with asphalt-rubber binder.
文摘Mechanochemically partially devulcanized ground rubber tire (GRT) was revulcanized in composition with virgin styrene butadiene rubber (SBR). Reclaiming of GRT was carried out by tetra methyl thiuram disulfide (TMTD) in presence of spindle oil. The cure characteristics and tensile properties of SBR compounds were investigated. Results indicate that the minimum torque and Mooney viscosity of the SBR compounds increase with increasing reclaim rubber (RR) loading whereas the scorch time remain unaltered but optimum cure time exhibit a decreasing trend. Increasing RR loading also gives SBR compounds better resistance towards swelling but the 100% modulus, 200% modulus tensile strength, and the elongation at break increases. Thermogravimetric analysis of SBR/RR vulcanizates was carried out in order to get thermal stability of the vulcanizates. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the SBR/RR vulcanizates.
文摘Thermoplastic elastomeric blends prepared from blending of (10%, 20%, 30%, 40% and 50 wt%) high density polyethylene(HDPE) and (10%, 20%, 30%, 40% and 50 wt%) ground rubber tire (TPV-R). The blends prepared contain (HDPE)/polybutadiene (TPV-V). The two blends were successfully prepared through a dynamic vulcanization process, involving dicumyl peroxide (3%) as vulcanizing agent. The data of the mechanical (tensile strength at yield, %elongation and young modulus) and rheological properties (shear stress, shear rate, viscosity, flow behavior index and activation energy of melt flow) of the TPV-V and TPV-R showed that there was comparable results between the two blends.
文摘The presence of waste tires poses an environmental challenge as they occupy a significant amount of land and are expensive to dispose in landfills.However,reusing waste tires can address this issue when waste tires are used in geotechnical applications.To determine the viability of this approach,laboratoryscale tests were conducted to investigate load-bearing capacity of circular footings on sand-tire shred(STS)mixtures with shredded waste tire contents of 5%e15%by weight and three different widths of shreds.The investigation focused on analyzing the thickness of layers composed of STS mixtures,the soil cap,and the impact of geogrids on bearing capacity.The results indicate that a specific mixture of sand and tire shreds provides the highest footing-bearing capacity.In addition,the optimal shred content and size were found to be 10%by weight and 2 cm×10 cm,respectively.Furthermore,for a given tire shred width,a particular length provides the largest bearing capacity.The results agree well with that of previous research conducted by the first author and his colleagues in direct shear and California bearing ratio(CBR)tests.The primary finding of this research is that the use of two-layered STS mixtures reinforced by geogrids significantly enhances the bearing capacity.
文摘Pneumatic tire modeling and validation have been the topic of several research papers, however, most of these papers only deal with pneumatic passenger and truck tires. In recent years, wheeled-scaled vehicles have gained lots of attention as a feasible testing platform, nonetheless up to the authors’ knowledge there has been no research regarding the use of scaled tires and their effect on the overall vehicle performance characteristics. This paper presents a novel scaled electric combat vehicle tire model and validation technique. The pro-line lockdown tire size 3.00 × 7.35 is modeled using the Finite Element Analysis (FEA) technique and several materials including layered membrane, beam elements, and Mooney-Rivlin for rubber. The tire-rim assembly is then described, and the rigid body analysis is presented. The tire is then validated using an in-house custom-made static tire testing machine. The tire test rig is made specifically to test the pro-line tire model and is designed and manufactured in the laboratory. The tire is validated using vertical stiffness and footprint tests in the static domain at different operating conditions including several vertical loads. Then the tire is used to perform rolling resistance and steering analysis including the rolling resistance coefficient and the cornering stiffness. The analysis is performed at different operating conditions including longitudinal speeds of 5, 10, and 15 km/h. This tire model will be further used to determine the tractive and braking performance of the tire. Furthermore, the tire test rig will also be modified to perform cornering stiffness tests.
基金funded by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.N2023J053).
文摘Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.