Crumb Rubber Research Articles

Impact of sand to aggregate ratio on mechanical properties and micro-structures of waste crumb rubber concrete

The replacement of natural river sand with crumb rubber (CR) in crumb rubber concrete (CRC) has attracted attention for its remarkable toughness and environmentally friendly properties. Sand to aggregate ratio (SAR) needs special attention as an important parameter in the mix proportions design of CRC as the CR volume fraction will vary with the SAR, affecting the particle packing within the CRC and therefore having a significant impact on the CRC properties, such as workability, mechanical properties and micro-structures. Thus, present study discusses the impact of SAR on both fresh and hardened properties of CRC. Relationship between SAR and workability, strength (including compressive and flexural-tensile), dynamic elastic modulus and damping ratio are analyzed. Cumulative pore size distribution and micro-morphology for each mixture were assessed using mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) technology. Results show that the workability increases slightly and then decreases significantly with increasing SAR, and the best workability is demonstrated at a SAR of 40%. Wet packing density, compressive strength, and dynamic elastic modulus showed a monotonically decreasing trend with SAR from 30% to 70% due to the weaker bonding properties of the CR particles. Flexural-tensile strength and damping ratio exhibited an initial increase followed by a decrease with SAR, reaching peak values at 50%, measured at 9.75 MPa and 1.91%, respectively. Cumulative pore volume increased from 0.3244 to 0.4315 as SAR rose from 30% to 70%, potentially contributing to the decline in compressive strength and elastic modulus. Additionally, the micro morphology appeared to be more loose with the increase in SAR. Relationship between SAR and the above indicators is modelled. Radar charts were created to analyze the influence of SAR on the overall performance of CRC. The relative area shows a significant decrease when SAR exceeds 50%.

The EDUKASI DAMPAK PERILAKU TINDAKAN TIDAK AMAN PADA KARYAWAN BAGIAN PRODUKSI DI PT. ADEI CRUMB RUBBER INDUSTRY

W.H Heinrich stated that 88% of workplace accidents are caused by unsafe acts. Employment tenure refers to the period of time an employee works in a particular place. Attitude is an individual's tendency to respond in a specific way to stimuli. Unsafe behavior is human behavior that deviates from proper work procedures, thereby endangering oneself. The purpose of this outreach program is to provide education on the impact of unsafe behavior to workers at PT Adei Crumb Rubber Industry. Consequently, the expected outcome of this counseling is for the workers at PT Adei Crumb Rubber Industry to work with safe behavior to avoid accidents and work-related illnesses, as well as to enhance the company's role in implementing a safety culture (K3).

Experimental investigation into the properties of crumb rubberized concrete incorporating corrugated round steel fibers

This paper presents an experimental study on how crumb rubber particles from waste tires and corrugated round steel fibers affect the mechanical behavior of concrete. In addition to the standard plain mix and five combinations of mixes composed of 0.5%, 1.0%, and 1.5% ratios, three steel fiber and crumb rubber mixes, 0.5%, 1.0%, and 2.0% weight of sand, coarse aggregate, cement, and silica fume were evaluated. The percentage of silica fume that replaced the weight of the cement in this study was 8%. The fresh properties of the 12 mixtures in terms of slump and density were studied. After 28 days of curing 36 cubes, 36 cylinders, and 12 prisms, the hardened properties were determined by evaluating the mean compressive, split, and flexural strengths. The results indicate that a synergetic effect is observed for the combination of crumb rubber and corrugated round steel fibers to improve the fresh and hardened properties of concrete. Adding fiber reinforcement to concrete can mitigate the negative impacts of rubber, and vice versa. According to the combination content, increases in compressive strength, tensile strength, and flexural strength of up to 49.04%, 38.60%, and 75.76%, respectively, were achieved compared with the control combination. This validates the applicability of the proposed mathematical prediction formulation to evaluate the compressive strength, split tensile strength, and modulus of rupture of rubberized fibrous concrete in terms of fiber and rubber ratios. Based on these results, a promising solution for tire disposal is to recycle waste rubber for fibrous concrete applications.

Sustainable innovation in self-compacted concrete: Integrating by-products and waste rubber for green construction practices

Due to increasing concern about global climate change and its negative influence on societies, there is a specific focus on the construction sector as the greatest contributor to greenhouse gas emissions. About 8–10% of global CO2 emissions come from cement production, which releases almost a ton of CO2 for every ton of cement. Growing demand for cement and concrete is attributed to rapid urbanization, industrialization, and economic growth, which also substantially impacts the depletion of natural resources. To address these challenges, a feasible approach is to utilize by-product materials and waste rubber as alternatives to cement and natural fine aggregates in producing self-compacted concrete (SCC). The utilization of various percentages of fly ash (FA), ground granulate blast furnace slag (GGBFS) as cement replacement, and crumb rubber (CR) from waste tires as a partial substitution of fine aggregate offers a suitable choice for the development of sustainable SCC. In addition, compressive strength (CS) is a vital property when considering other characteristics of concrete. Therefore, it is vital to develop reliable models for predicting the CS of SCC to achieve cost, time, and energy savings. Therefore, this research examines the impact of various contents of FA and GGBFS as cement (C) alternatives and CR as a sand replacement on the CS of SCC. To predict the CS of rubberized SCC mixtures, four different models were employed: linear regression (LR), multi-linear regression (MLR), full quadratic (FQ), and M5P-tree. To accomplish this, a comprehensive set of data comprising approximately 436 samples was analyzed to develop the models; as input variables, various mixture proportions, and curing ages were considered. To ensure the accuracy and reliability of the predictive models, several statistical assessments were performed. Based on the statistical assessment tools conducted in this study, the FQ model is considered the most effective model for forecasting the CS of SCC. Based on the statistical assessment tools, the FQ model was also implemented to forecast the splitting tensile and flexural strengths of SCC. The sensitivity analysis indicates that CR and GGBFS content are the best criteria for forecasting the CS of SCC utilizing this data set.

Design and analysis of bituminous construction mixes for flexible pavement by adding industrial waste

The study focused on utilizing industrial waste, which consists of various materials rendered unusable during manufacturing processes, for designing a bituminous mix for flexible pavement. The researchers collected the waste material and prepared a mixed composition of industrial waste. They evaluated the properties and quality of the mixed composition when combined with bitumen. Marshall mix samples were created using different bitumen contents and the mixed waste composition, with only 5% utilization of crumb rubber (CR) in the experimental work. The study found that the most optimal results were achieved with the addition of 3% low-density polyethylene (LDPE), 4% waste engine oil (WEO), and 5% CR with a bitumen content of 4.5%. The analysis revealed a maximum stability value of 727.5 kg and a flow value of 16.15. However, it was concluded that increasing the limit of LDPE, WEO, or CR could lead to brittleness and significant deformation in the mix.

A Study of Flexible Pavement with Replacement of Bitumen with Melted Tyres& Recycled Aggregates using ANN Technique

Artificial neural network is a data processing mathematical model based on biological neurons. It is a complex structure composed of interconnected neurons that can be used to solve problems and perform tasks. Two essential construction materials in the industry are crumb rubber and destroyed aggregates. For accurate Marshall Stability mix proportioning, this work establishes the usage of ANNtechniques. Five of the most widely used statistical metrics are Pearson correlation coefficient, mean absolute error, and root mean square errors. When compared to other applied models, ANN produces better results. Proposed models should save money in terms of materials, labour, and time while also improving accuracy. The recommended concrete should be more cost-effective and long-lasting.The recommended values such as CC= 0.9484, Mean Absolute error=0.7988, RMSE=0.9478 represents that the result should be more cost-effective and long-lasting.

The Usage of Additives on Porous Asphalt

Roads are an important infrastructure component, but often face problems such as changes in temperature, humidity, and standing water. To overcome this problem, a layer of porous asphalt which has air voids to reduce standing water on the road surface can be a solution. However, although porous asphalt has water-related benefits, its structure is less durable and requires increased resistance. Therefore, this study aims to analyze the effect of adding additives on the strength, permeability, and porosity of porous asphalt. Three types of additives studied were crumb rubber (CR), nano silica (NS), and Wetbond-SP. Several laboratory tests were conducted on the prepared specimens, namely the Marshall, Cantabro Loss, and permeability tests. The results showed that adding NS onto the specimen was able to increase the stability value of porous asphalt, while the addition of CR and Wetbond-SP had no significant effect on the stability parameter. However, the addition of Wetbond-SP improved the adhesion between the aggregate and asphalt, resulting in a denser mixture. The three additives also increased moisture resistance and cohesion loss in the mixture, as indicated by a decrease in Cantabro Loss (CL) percentage. Additives also impact the permeability and porosity values, where adding more additives in the mixture will reduce the permeability and porosity values. Based on the results of the study, the optimum concentration of CR added was 1% of the total weight of the mixture, NS was 4% of the weight of asphalt content, and Wetbond-SP was 0.4% of the weight of asphalt content.

Fillers to improve the ductility and impermeability of crumb rubber concrete

Crumb rubber concrete (CRC), a type of eco-friendly concrete materials, has attracted pronounced interest in the field of infrastructure construction and waste management. However, special attention should be paid to its permeability since it is an important indicator to determine its service life for building structures, especially in coastal regions. Present study discusses the feasibility of pozzolanic fillers to improve the ductility and impermeability of CRC. By incorporating fly ash (FA), silica fume (SF), and ground granulated blast furnace slag (GGBFS), fresh properties, mechanical strength and chloride resistance of CRC were evaluated. Results show that the fillers adopted enhance the toughness of CRC in terms of ductility index considering splitting-tensile and compressive strength, among which SF has the most positive effect. Micro-aggregate effect of FA particles, high active silica content of SF and more Friedel's salt formation are the main reasons for the improved impermeability of CRC. Radar charts are plotted to analyze the overall performance of CRC with fillers. Relative area values indicate that SF exhibits the most significant improvement in CRC performance, followed by GGBFS and FA.

Use of Waste Rubber Material as Crumb on Road Construction

Abstract: The growth rate of vehicles is the backbone of economic development of any country. India is the second fast growing automobile industry in the world. In today’s era, solid waste management is the thrust area. On the other side, the traffic intensity is also increasing. As a result, amount of waste tyres is also increasing. The increasing consumption of waste tire has generated many problems such as increasing landfill space, environmental pollution and causing health hazards. Parallel to this is the increasing of roads construction because of heavy traffic on roads. This study reviews to the use of crumb rubber (waste tires in powder form) in bitumen using the wet process. The study focuses on the crumb rubber as a replacement to the total weight of bitumen. The design or life span for all highways and urban roads is 10 – 20 years. Unfortunately, damages or distresses on pavements are still occurring before reaching the maximum period of the designed road serviceability. Among the major influencing factor that is contributing to this distress is the repeated heavy traffic loading on the road surfaces. Moreover, the use of waste crumb rubber in road construction as a pavement surface has a better skid resistance, fatigue crack resistance and increased rut resistance. The review includes physical tests that are used to determine the physical properties of bitumen and modified crumb rubber mix. The physical tests involve penetration test, softening point test, and ductility test. The expectations from the study are to develop bitumen with waste crumb rubber that would minimize the costs of bitumen and providing better physical properties compared to the convention bitumen based on the tests that was conducted.

Selection of Either (Fly Ash, Rubber And Rice Husk) Material for Rigid Pavement: Review

Abstract: Road transportation plays a crucial role in India's economic development, providing cost-effective, accessible, and adaptable means of transportation for both passengers and freight. Pavement, as a key component of highway design, must withstand vehicular loads and foot traffic while ensuring safe and efficient movement. This paper reviews existing literature on pavement materials, focusing on sustainable alternatives such as fly ash-based geopolymers, basalt fiber-reinforced concrete, and asphalt mixtures incorporating recycled aggregates and rubber. Additionally, it proposes the combination of rice husk and crumb rubber in concrete as a sustainable approach for pavement construction. The study aims to evaluate the mechanical properties of concrete with partial material replacements through experimental investigation. By addressing gaps in durability studies, comparative analysis, and non-destructive testing, this research seeks to provide valuable insights into the feasibility and sustainability of utilizing waste materials in concrete production. Ultimately, it aims to contribute to advancing sustainable practices in the construction industry and addressing the challenge of waste accumulation.

Use Crumb Rubber Chips in Partial Substitution of Coarse Aggregate While Preparing Concrete

Abstract: The purpose of this experimental investigation is to examine the behaviour features of rubberized concrete, which has coarse aggregate in place of some of the tyre rubber. Over 270 million scrap tyres are thought to be produced annually. One of the main problems in India is the disposal of discarded tyres in landfills, which is the responsibility of local governments and municipalities. Because it is not biodegradable, there are serious concerns to human health, the environment, and fire. The most promising uses of tyres in engineering are as aggregates for asphalt and concrete, artificial reefs, and erosion management, aside from gasoline obtained from tyres. Concrete's characteristics could be greatly improved in a variety of ways by using recycled tyre rubber as part of the aggregate. One of the most often used building materials is concrete. Because of this, the building sector is constantly looking for new applications and uses for its products, as well as ways to improve them while keeping costs down. The reference concrete specimen is made of M30 grade concrete. Rubber chips from scrap tyres have been utilised in place of traditional coarse aggregate as coarse aggregate. This will enable the efficient and widespread handling of rubber tyre waste in addition to enabling the sustainable use of the aggregates that are already accessible to us. After separating the rubber tyre waste into coarse chips, this tyre crumb aggregate is applied in increments of 5%, 10%, or 15% to replace the coarse aggregate. In order to determine the best way to employ crumb rubber as coarse aggregate in concrete, this study assessed the workability and compressive strength of rubberized concrete

Incorporting Tire Dust in Roadworks

Abstract: In this study the changes that are incurred in the properties of bitumen upon adding scrap tire dust in it are investigated. The basic properties of bitumen are Ductility, Softening Point and Penetration Value. These values change depending on the grade of bitumen. The objective of this study is to determine the rate of change of basic bituminous properties and other key properties such as Marshall Stability and Flow Rate of Dense Bituminous Macadam due to addition of scrap tire dust in bitumen. Crumb Rubber Modified Bitumen is acquired by adding certain amount of tire dust in bitumen, in this study 10% and 30% of bitumen is replaced with scrap tire dust and their properties are compared with the properties of pure bitumen. Modifying bitumen with scrap tire dust increases the stability, flow rate, penetration value and softening point which makes it more resistant to loading and temperature. Incorporating scrap tire dust in roadworks also helps in reducing the overall volume of waste tires. Scrap tires are often a breeding place for mosquitoes as tires contain huge concentration of carbon. Burning of tires leads to even greater hazards. So, through modifying bitumen with tire dust we can prevent harm to environment and enhance the properties of Bitumen

Development of Pervious Concrete with Enhanced Skid Resistance using Waste Tires Particles

Rubber tires are excessively increasing with the advancement in transportation technologies. It is difficult to dispose off the tires and as such they cause environmental threats to the on-land and aquatic lives. In this work crumb rubber is used as a fractional replacement of sand in concrete at 5%, 10% and 15% by mass. The aim is to produce a porous concrete with acceptable mechanical strength and high skid resistance. The workability and fresh density of the concrete decreased with the crumb rubber. Similar reduction in mechanical strength was also noticed, however, 5% replacement showed mechanical properties similar to those of the control units. The crumb rubber enhanced the porosity of the material. The study as a whole suggests that a lightweight concrete with enhanced porosity and skid resistance can be produced by recycling crumb rubber as a partial replacement of sand. The porous concrete with good skid resistance is a useful pavement material as it allows the infiltration of rainwater through it and thus has the capacity to reduce runoff during heavy rainfalls. It can additionally help reduce the accidents due to higher skid resistance in wet conditions.

Thermal Oxidative Aging Effect on Chemo-Rheological and Morphological Evolution of Crumb Rubber Modified Asphalt Binders with Wax-Based Warm Mix Additives

Wax-based warm mix additives can decrease the viscosity and improve the workability of crumb rubber (CR)-modified asphalt, but the mechanism of influence on the aging performance of CR-modified asphalt is not clear. To investigate the thermal aging behavior and mechanism of wax-based warm mix CR-modified asphalt, polyethylene wax (PEW) and polyamide wax (PAW) were mixed to prepare warm mix CR-modified asphalt. The effect of thermal aging on the rheological and mechanical properties was characterized by a basic property test, frequency sweep test, and multiple stress creep recovery test. The chemical composition changes during aging were then analyzed by Fourier transform infrared spectroscopy and gel permeation chromatography. Finally, the phase morphology during thermal aging was observed by fluorescence microscopy. The results showed that compared with the degradation of CR, the oxidative aging of the asphalt binder played a dominant role in the process. Not only did PEW and PAW attach to the asphalt surface in the form of crystallization to prevent its reaction with oxygen but they also promoted the dissolution of CR, and released polymerization chains, thereby enhancing the antiaging properties of CR-modified asphalt. Furthermore, the antiaging of PAW/CR-modified asphalt was better than that of PEW/CR-modified asphalt, because the amide group of PAW reacted with CR-modified asphalt to form a polymer structure.

Devulcanized crumb rubber as bitumen modifier

Devulcanized crumb rubber as bitumen modifier

Desulfurization of crumb rubber by modified natural zeolitic catalysts

Desulfurization of crumb rubber by modified natural zeolitic catalysts

Analytical evaluation of stress–strain behavior of rubberized concrete incorporating waste tire crumb rubber

The advancement of rubberized concrete technology and its application in engineering can significantly promote the complete recycling and safe disposal of waste tire rubber. Integrating crumb rubber into concrete alters its compressive stress–strain behavior. This study investigated the stress–strain characteristics of rubberized concrete containing waste tire crumb rubber, addressing the absence of standard guidelines for the design of rubberized concrete. By examining the complete stress–strain curves of rubberized concrete, key parameters such as peak stress, initial elastic modulus, peak strain and secant modulus were meticulously evaluated. The study delved into the mechanisms through which crumb rubber influences the stress–strain behavior of concrete, considering factors including variations in rubber content and pretreatment methods. The experimental data were analyzed using conventional concrete constitutive theories to quantify the impact of crumb rubber on rubberized concrete's stress–strain relationship. Significant variations were observed, including a notable decline in strength with increasing rubber content. For instance, increasing the rubber content from 0.0% to 5.0% led to reductions of 44.2% in peak stress and 47.0% in secant modulus compared to the reference concrete. In addition, pretreating the crumb rubber markedly improved rubberized concrete strength, and the peak stress of concrete with 1.0%–5.0% pretreated crumb rubber increased by an average of 7.0% compared to that with untreated crumb rubber. The study identified that crumb rubber's inclusion significantly altered the coordination of stress and strain in concrete, thereby affecting its stress–strain behavior. A set of evaluation equations for the stress–strain relationship of rubberized concrete was developed, offering a reliable method for predicting its behavior. This research fills a critical gap in the analytical assessment of rubberized concrete and marks a significant stride towards its broader use in sustainable construction practices.

Unleashing the Flexural Behavior of Ceramic Hybrid Rubber Reinforced Composites for Sustainable Industry

An innovative methodology is employed to explore the potential of repurposing floor ceramics and used tire rubber for fine aggregate. In contrast to one-way ordinary concrete slabs, the behavior of Ceramic Hybrid Rubber Reinforced Composite Slabs (CHRRCS) under pure bending has been thoroughly examined. There is no discernible negative effect of the quantity of ceramic floor tiles on the characteristics of concrete. In this study, M30 concrete with a water-to-cement ratio of 0.38 is employed. The distribution reinforcement was made up of bars with an 8 mm diameter, while the main reinforcement was made up of 10 mm diameter Fe 415 grade steel bars. The CHRRCS with 2% rubber fibers, 10% replacement ceramic, and 10% pre-treated crumb rubber exhibit more significant deflection only under extreme stress conditions. Apart from the experimental study, ABAQUS was used to perform a finite element model in three-dimensional simulation and analyze the load-displacement behavior. The comparison of ABAQUS simulation and experimental data yields a fair range. The flexural performance of CHRRCS is enhanced in pure bending.

ENSURING INCREASED DURABILITY OF PAVEMENT ON REINFORCED CONCRETE ROAD BRIDGES

The article contains the results of a study on increasing the durability of pavement on reinforced concrete road bridges by using rubber crumb. The pavement on reinforced concrete road bridges is one of the main structural elements of the structure, the technical condition of which affects the safety of the structures as a whole.
 Given the constant increase in traffic intensity and load on the road network, as well as insufficient funding for major repairs or reconstruction, it is necessary to use materials that ensure reliable operation of the roadway of bridge structures to increase the durability of the asphalt pavement.
 The asphalt concrete pavement of a roadway has a number of important factors that ensure the safety and comfort of vehicular traffic, namely: flatness, low noise and roughness, which provides the necessary grafting coefficient with the car tires while driving. However, it should be noted that during operation, such a coating is easily exposed to unfavorable factors, which leads to premature deformation in it.

Evaluation of Geopolymer Concrete Based on Fly Ash Containing Steel Fibers and Rubber Crumbs Using Cement as a Partial Substitute for Fly Ash

In this study, geopolymer concrete made from fly ash was utilized, with different proportions of cement (0%, 10%, and 20%) replacing fly ash to examine the influence of cement presence in geopolymer concrete. To increase tensile strength and impact resistance, 0.5 and 1 percent steel fibers were used. Adding 0.5 percent fibers improved compressive strength by 9 percent, and for 1 percent fibers, it was 26 percent. The tensile strength also significantly increased with the addition of fibers. Adding 0.5% fibers, on average, increased the tensile strength by 25%, with the increase being 34% for 1% fibers. It was also noted that substituting cement for fly ash had little effect on compressive strength, but replacing 10% cement could be considered as the optimal substitution level in terms of tensile strength in the samples. The test results for impact resistance indicated a significant effect of steel fibers on the number of impacts until the first crack appeared and the complete rupture of the samples. Adding fibers increased the resistance to complete rupture by 12 to 22 percent with 0.5 percent fibers, and between 49 to 64 percent for 1 percent fibers. Replacing 10 percent rubber crumbs improved the impact energy of concrete, increasing the energy until the first crack by 10 percent on average and the energy until complete rupture by 15 percent.