Rubber Content Research Articles

Rubberized Concrete: Effect of the Rubber Size and Content on Static and Dynamic Behavior

Rubberized concrete (RC) has received widespread attention due to its energy absorption and crack resistance properties. However, due to its low compressive strength, it is not recommended for structural applications. The rubber size and content affect RC’s mechanical properties. This study investigated and formulated the behavior of RC with different particle sizes and contents under dynamic and static loading. Quasi-static compressive and dynamic tests were conducted on RC with varying content of rubber (0–30%) and rubber sizes (0.1–20 mm). It was found that the rubber particle size was 0.5mm and the rubber content was 2%. An equation was derived from the experimental data to forecast the impact of rubber size and content on compressive strength. Additionally, by combining the literature and this research’s data, a model was established based on neural networks to predict the strength of RC. SHPB tests were carried out to study the stress–strain curves under dynamic load. The peak stress, fragment analysis, and energy absorption of RC with varying content of rubber and rubber sizes at three different strain rates (100 s−1, 160 s−1, and 290 s−1) were investigated. Equations describing the relationship between dynamic increase factor (DIF), rubber material content, and strain rate on different particle sizes were obtained by fitting. The DIF increased as the content of the rubber increased. By analyzing energy absorption data, it was found that the optimal ratio for energy absorption was RC-0.5-30, RC-0.1-30, and RC-10-30 at strain rates of 100 s−1, 160 s−1, and 290 s−1. This study could be a good guideline for other researchers to easily select the content and size of the rubber in RC for their applications. It also has a positive significance in promoting the development of green building materials.

Design and development of a system based on transient hot wire technique to determine dry rubber content in natural rubber latex

Design and development of a system based on transient hot wire technique to determine dry rubber content in natural rubber latex

Assessing the rheological properties of bio modified asphalt cement

The production of asphalt cement binder in Iraq is conducted through the distillation of crude oil. The byproduct of such distillation is the asphalt cement which does not practice any further processing further processing of the binder is considered vital to control its physical properties and chemical composition. The implementation of bio-modifiers before using such asphalt cement binder for paving work is a sound practice to enhance its sustainability and reserve the required rheological properties. In the present study, the asphalt cement binder was modified by implementation of extender oil (used diesel engine oil) and scrap tire rubber. The aim of this work is to improve and provide a sustainable and proper rheological quality of the binder for paving work. Various percentages of scrap tire rubber and extender oil have been tried to optimize the modifiers which can exhibit a suitable control on the required rheological properties of the asphalt binder such as the stiffness modulus, its temperature susceptibility in terms of penetration index and penetration viscosity number, and temperature of equivalent stiffness of the binder. The stiffness of asphalt cement binder was digested at hot, moderate, and cold environments. It was observed that the implementation of extender oil was able to reduce the penetration index (PI) by 36.3%, 54.5%, and 27.2% when 15%, 10%, and 5% of extender oil by weight of the mixture were added respectively to the control binder. The addition of scrap tire rubber to the binder-oil mixture was able to reduce the PI up to 10% of rubber content and exhibited further control of the temperature susceptibility of the binder. It can be revealed that the extender oil increases the negative values of penetration viscosity number (PVN) while the scrap tire rubber can improve the PVN of the binder. When high percentage of extender oil 15% is implemented, the stiffness of the binder declines by 50%, 90%, and 75% when the testing temperature change from 4 to 25, and 60 ℃ respectively. It was concluded that implication of 15% of scrap tire rubber and 15% of extender oil into the asphalt cement binder produced by Qayarah oil refinery is recommended to provide a sustainable binder for pavement, control its temperature susceptibility, and provide a binder with lower prone to pavement distresses.

Efficient synthesis of high vinyl polybutadiene based on continuous flow microchannel reactor

AbstractThe traditional batch synthesis of liquid rubber faces issues such as low monomer polymerization concentration, poor uniformity of the reaction system, and inadequate heat dissipation, resulting in an unsatisfactory synthesis efficiency. This study presents a method for the rapid and efficient synthesis of high vinyl 1,2‐polybutadiene liquid rubber using butadiene as the monomer and n‐butyllithium as the initiator. By applying continuous flow microchannel reactors, the limitation of traditional synthesis method can be overcome. The addition of a modifier in the raw material promotes the formation of high vinyl structure. The preparation of liquid rubber requires the addition of a large amount of metal lithium initiator. However, for aerospace sealants, there is a requirement for low metal ion content. To address this, we employed different methods to reduce the metal ion content in the liquid rubber and increase its purity. Ultimately, we achieved the synthesis of high‐purity polybutadiene liquid rubber with 1,2‐vinyl content exceeding 88%, narrow molecular weight distribution, and tunable molecular weights. This research will provide technical guidance for the industrial application of polybutadiene synthesis in continuous flow microchannel reactors.

Mechanical Performance of Steel-Fiber-Incorporated Rubberized Concrete for Rigid Pavement Applications

Sustainable solutions are required to mitigate waste tire accumulation. Using rubberized concrete (RuC) in rigid pavements is a viable and relatively environmentally friendly strategy for partially replacing fine/coarse aggregates with crumb rubber. However, crumb rubber affects the mechanical properties of concrete. Although RuC is more flexible (ideal for road pavements) than conventional concrete, its strength is lower than that of the standard concrete used in rigid pavements. Consequently, the crumb rubber generated from discarded tires cannot be used sustainably. The primary objective of this study was to characterize RuC mixed with manufactured steel fibers to improve the strength of the mixture. Fine aggregates (sand) were partially substituted with various proportions (10%, 20%, and 40%) of crumb rubber (size:1.70–2.36 mm) while incorporating 0.5% steel fibers (by volume). The compressive strength, splitting tensile strength, and flexural strength of the concrete deteriorated with increasing rubber content, consistent with the previously reported results. However, steel fiber incorporation improved the mechanical behavior of RuC, thus enhancing the compressive strength, splitting tensile strength, and flexural strength of the pavement structure. The developed steel-fiber-incorporated RuC design enhances the usability and economic value of RuC as well as minimizes the adverse environmental impact of concrete pavement technology.

Effect of Varied Cure Temperature on the Cure Behavior, Mechanical Properties and Heat Build-Up of Solid Tire Tread Compound Containing Different Particles Sizes of Ground Tire Rubber

This work investigates the effect of variation in vulcanization temperature on the cure behavior, tensile properties, tear strength, hardness, Akron abrasion loss and heat build-up of vulcanized tire tread compound in which the total rubber was replaced with 10% and 20% ground tire rubber (GTR) of 40, 60 and 80 mesh sizes. The first step was the characterization of the GTR using optical microscopy and a thermogravimetric analyzer. The first step of mixing each rubber compound was carried out using an internal mixer (Brabender) at 60°C and 40 rev/min rotor speed and the second step was done on a two-roll mill. The mooney viscosity of each rubber compound was investigated. the cure behavior of the rubber compounds was studied at 140°C, 150°C, and 160°C respectively. Results show that the introduction of GTR reduced vulcanization time, while increased cure temperature resulted in a lower vulcanization time. No significant difference was observed in the vulcanization time at a particular temperature of the rubber sample with different particle sizes and varied amounts of GTR. The introduction of ground tire rubber in the rubber vulcanizate however resulted in decreased tensile strength, tear strength and elongation, and increased hardness, abrasion resistance, modulus and heat build-up. An increase in the vulcanization temperature from 140°C to 150°C and 160°C did not impart a significant reduction in the tensile strength of the vulcanizates containing GTR. Vulcanization at higher temperatures resulted in reduced hardness, and modulus, slightly increased abrasion loss and increased elongation of the vulcanizates containing GTR. The heat build-up increased as the cure temperature increased. Generally, the control sample with no content of ground tire rubber exhibited the best properties. If GTR is to be introduced in rubber matrix at an amount up to 20%, the results suggest that 60 mesh size particles will impart better properties. The optimal vulcanization temperature recommended based on the findings from the work is 150°C.

Effect of Silicone Rubber on the Properties of Epoxy/Recovered Carbon Black (rCB) Conductive Materials

The primary focus of this study is to investigate the effect of silicone rubber (SR) content on the mechanical, thermal, electrical conductivity, and morphological properties of epoxy/recovered carbon black (rCB) conductive material. The conductive material is used to produce the electrostatic discharge (ESD) tray for the electronic packaging industry. This study investigated the effect of silicone rubber content (0, 5, 10, 15, and 20 vol.%) on the properties of epoxy/SR/rCB conductive materials, with the rCB content fixed at 15 vol.% for its optimum electrical conductivity. The silicone rubber acts as a toughening agent for epoxy. Through the fracture toughness result, it can be identified that silicone rubber plays a role in improving the toughness properties of the epoxy/SR/rCB conductive material. The optimum results for mechanical properties were recorded at 5 vol.% SR. The addition of SR to the epoxy matrix enhances the electrical properties of the epoxy/SR/rCB conductive material. The effect of thermal aging on epoxy/SR/rCB conductive materials was also studied to determine the properties of the conductive material materials at high temperatures for a long period of time. After thermal aging, the mechanical, thermal, electrical conductivity, and morphological properties of the epoxy/SR/rCB conductive material were slightly reduced.

Natural coal-derived graphite as rubber filler and the influence of its progressive graphitization on reinforcement performance

This study introduces a reinforcing rubber filler, natural coal-derived graphite (NCDG), evaluating how its progressive structural evolution from meta-anthracite (MA), semi-graphite (SG) to cryptocrystalline graphite (CG) during the natural graphitization process affects their reinforcing performance to styrene-butadiene rubber (SBR) composites. The highly graphitized NCDG fillers exhibit good filler dispersion, more bound rubber content, and well compatibility between filler and rubber matrix when compounded with SBR, and significantly enhance the mechanical properties of SBR composite (tensile strength can reach 22.8 MPa), as well as improving the storage modulus, wet-skid resistance, wear resistance, and electrical conductivity. The formation of microcrystalline multilayer graphene and graphene nanoplatelets exfoliated by mechanical shear stress during ball grinding and rubber compound mixing plays an important role in improving the reinforcement performance of rubber composites. This research provides valuable insights into the utilization of NCDG as a cost-effective and environment-friendly reinforcing filler for rubber composites.

Positive regulation of the Eucommia rubber biosynthesis-related gene EuFPS1 by EuWRKY30 in Eucommia ulmoides

Eucommia rubber is a secondary metabolite from Eucommia ulmoides that has attracted much attention because of its unique properties and enormous potential for application. However, the transcriptional mechanism regulating its biosynthesis has not yet been determined. Farnesyl pyrophosphate synthase is a key enzyme in the Eucommia rubber biosynthesis. In this study, the promoter of EuFPS1 was used as bait, EuWRKY30 was screened from the cDNA library of EuFPS1 via a yeast one-hybrid system. EuWRKY30 belongs to the WRKY IIa subfamily and contains a WRKY domain and a C2H2 zinc finger motif, and the expressed protein is located in the nucleus. EuWRKY30 and EuFPS1 exhibited similar tissue expression patterns, and yeast one-hybrid and dual-luciferase experiments confirmed that EuWRKY30 directly binds to the W-box element in the EuFPS1 promoter and activates its expression. Moreover, the overexpression of EuWRKY30 significantly upregulated the expression level of EuFPS1, further increasing the density of the rubber particles and Eucommia rubber content. The results of this study indicated that EuWRKY30 positively regulates EuFPS1, which plays a critical role in the synthesis of Eucommia rubber, provided a basis for further analysis of the underlying transcriptional regulatory mechanisms.

Dynamic compressive behavior of environmentally friendly high-strength concrete: Experimental investigation and modelling

In this study, the mechanical properties of rubber powder and recycled steel fiber made from waste tires as fine aggregate and reinforced fiber of environmentally friendly high strength concrete (E-HSC) were investigated, especially the dynamic response of E-HSC under dynamic loading. The failure mode, stress-strain curve and energy dissipation capacity of E-HSC were investigated with different rubber powder replacement rates (0%, 5%, 20%, 35%, 50%) and different RSF volume fractions (1%, 2%, 3%) by using a separated Hopkinson pressure bar with a diameter of 100 mm. Additionally, the environmental benefits of E-HSC were assessed through carbon emission evaluation. Results indicated that rubber powder and RSFs enhanced the compressive ductility of high-strength concrete. With an increase in the ratio of rubber powder replacement, the static compressive strength of E-HSC decreased, the strain rate sensitivity of E-HSC significantly increased, while the dynamic toughness of E-HSC was notably improved. The failure modes of E-HSC under impact loading changed with increasing rubber content, showing an increase in crack quantity and severity of fragmentation. The influence of RSF content on the strain rate sensitivity of E-HSC's dynamic failure mode and toughness were not significant. A viscoelastic correction model considering impact damage was proposed, which can effectively describe the stress-strain behavior of E-HSC under impact loading across various strain rates. Furthermore, E-HSC demonstrated lower carbon emission indicators compared to traditional high-strength concrete.

Shear modulus and damping ratio of granulated rubber-sand mixtures: Influence of relative particle size

Rubber-sand mixtures (RSM) have gained recognition as a valuable, lightweight, and cost-efficient energy-absorbing material with extensive potential application in engineering construction. However, the small-strain dynamic properties and prevailing mechanisms of RSM have not been thoroughly understood. This study conducted a series of resonant column tests on the small-strain dynamic modulus and damping ratio of RSM, considering the effects of particle size ratio (PSR), rubber content (RC), and confining pressure. The results reveal that the dynamic shear modulus of RSM generally decreases with increasing RC and increases with rising confining pressure. For all RC and confining pressure levels, the maximum dynamic shear modulus of RSM reaches the minimum value as the PSR approaches 1.0. In this case, the dynamic shear modulus of RSM decreases most gently with the strain. The addition of rubber consistently augments the damping ratio, whereas the PSR initially diminishes the damping ratio before eventually enhancing it. Simultaneously, as the PSR is nearing 1.0, the damping ratio achieves its lowest point. Furthermore, new empirical equations were developed to quantitatively analyze the dynamic properties of RSM, in which the predicted values of the dynamic shear modulus and the modulus attenuation coefficient show good agreement with the observed values. This work will facilitate the preparation of artificial RSM-cored geotechnical seismic isolation layers tailored to specific engineering requirements.

Study on the nonlinear viscoelastic behavior of rubber composites filled with silica

Silica-filled rubber composites exhibit nonlinear viscoelastic behavior depending on filler dispersion and matrix interaction. This study investigated the effects of silane treatment on dynamic mechanical properties of precipitated and fumed silica-reinforced polybutadiene rubber composites. The silane coupling agent improved filler dispersion and interfacial adhesion as characterized by microscopy and bound rubber content. Payne effect measurements showed enhanced storage modulus and network stability for silanized composites due to better filler networking. Cyclic tensile loading displayed reduced stress-softening in treated composites attributable to minimized damage formation. Modeling using Kraus and damage mechanics approaches provided quantitative correlations between the microstructure and magnitude of nonlinear response. The results demonstrate that silane treatment optimizes the viscoelastic performance of silica-filled rubber composites.

Effect of ground tyre rubber content on self-healing properties of natural rubber composites

Abstract In this investigation, we study the influence of the loading of ground tyre rubber (GTR), referred to as rubber dust 40 mesh (RD40), on the intrinsic self-healing natural rubber (NR) based on metal-thiolate ionic networks. The loading of RD40 particles was varied at 10, 20, and 30 phr to assess the optimum amount for interfacial bonding, mechanical and dynamic properties, and healing efficiency. The quantitative measurement of metal-thiolate ion networks and covalent crosslinks was assessed through swelling tests. The effects of RD40 loading on the dynamic mechanical properties and morphological characteristics were also investigated. Tensile properties of the rubbers before and after healing were measured using universal testing tester to obtain healing efficiency of the materials. The results showed that the developed materials have the ability to autonomously repair themselves at room temperature without the need for manual intervention. The results also revealed the tensile strength and elongation at break of self-healing NRs filled with 10 phr of RD40 were recovered 92 % and 93 %, respectively. The findings demonstrated the benefits of utilizing GTR as an effective sustainable filler and advanced the understanding of self-healing strategies and the interaction between ground tyre rubber and rubber matrices.

Evaluating Guayule (Parthenium argentatum A. Gray) Germplasm Grown in Spain: Rubber and Resin along Three Production Cycles.

Rubber and resin are potentially important products of guayule (Parthenium argentatum A. Gray) that can assure the profitability of this crop as an agricultural alternative for the semi-arid areas of central and eastern Spain. This study analyzes, for the first time, the changes in rubber and resin production across 27 guayule accessions (traditional and modern) and along three cycles under the agroclimatic conditions of Castilla-La Mancha, simulating industrial management with a biannual harvest. The rubber content (% of dry mass) increased from 4.2% in one-year-old plants to 6.6% in two-year-old plants, but decreased after harvesting. Contrastingly, the rubber yield doubled in contiguous sampling, reaching a mean of 303.6 kg ha-1, with a maximum yield of 341.2 kg ha-1 after the first harvest. Three patterns of rubber production were established based on the production periods. A similar analysis was performed for resin production, which was heterogeneous across accessions belonging to the same rubber groups. In this case, three independent groups were established to classify the resin accumulation profiles following the same criteria of production periods. Here, we demonstrate that biannual harvesting has the potential to enhance rubber accumulation in summer, although more research is needed for its adaption to current harvesting techniques in this area.

Effect of rubberized concrete integrating uncoated and coated crumb rubber on the flexural behavior of the RC beams reinforced with steel and GFRP bars

In this investigation, crumb rubber (CR) was a viable substitute for concrete's conventional natural fine aggregate (FNA). This approach carries dual advantages: the conservation of natural resources and the environmentally conscious recycling of rubber waste, diverting it from traditional disposal methods. The study incorporated varying proportions of CR (5%, 10%, and 20%) by volume of the sand used in the mixtures. The primary study objective is to enhance the bond between CR particles and the surrounding concrete components by coating the CR with cement or fly ash slurry (CTR and FATR). For the limitation of the previous research discussed the CR effect on the beam’s behavior, fourteen beams were poured with different rubberized concrete (RuC) and tested in flexure. This comprehensive approach sought to assess the influence of diverse factors, including rubber content, treatment materials, and the nature of internal reinforcement, on the overall performance and characteristics of the beams. The results assumed that the compressive strength was raised by 6.0–11.0% and 13.0–22.0% for the mixes cast with CTR and FATR, respectively, compared to the corresponding mixes cast with UR. Consequently, the tensile strength of the RuC-integrated CTR and FATR was raised by 5.9–11.0% and 14.0–22.0%, respectively, compared to the mixes integrating uncoating CR. Moreover, the beams cast with FATR concrete experienced the highest flexural capacities among all the steel RC beams. Furthermore, using the carbon fiber reinforced polymer (CFRP) bars as internal reinforcement for the RC beams showed the highest load capacities.

Characterization of recycled nitrile butadiene rubber industrial scraps

The amount of rubber scraps derived from rubber goods production consists of about 20–30% of the processed material, so it is necessary to enhance this material by developing new recycling techniques as well as a new market for recycled rubber products. In the present research, nitrile-butadiene rubber (NBR) scraps are reprocessed via a calendering process acting with a mechanical devulcanization. Compounds were prepared with 20%, 80%, and 100% recycled rubber content and characterized. The experimental results highlighted that the compound prepared with 20% recycled rubber content via calendering and compression molding processes shows comparable mechanical properties to that of virgin NBR. The tensile properties are the most penalized by the increasing content of recycled material (100% recycled shows − 25% and − 50% stress and strain at break, respectively). Other properties remain comparable to the standard material up to 80% recycled material: 60 ± 5 Shore A, compression elastic modulus 8 MPa, compression set 20%. FTIR analysis revealed no changes in chemical structure from the recycling process. The results demonstrate that simple mechanical devulcanization can effectively reprocess industrial rubber waste while largely maintaining useful properties. This provides a potential pathway to enhance sustainability in rubber production through the valorization of process scraps.Graphical

Experimental study on cement-based materials for grouting/replacement of broken rock mass in coal mine

In deep high-pressure mines, the surrounding rock of soft broken roadways often faces issues such as poor anchorability, support difficulties, high maintenance costs, and the inadequacy of traditional materials for site requirements. To tackle these challenges, this study focuses on grouting reinforcement in coal mine sites and prefabricated bearing arch form (grouting or replacement) under specific conditions, aiming to meet the material requirements. Through an orthogonal test, various properties of cement-based materials were investigated, including fluidity, initial setting time, water separation rate, early (≤1d) compressive strength, fracture strength, and later (28d as a reference) strength. The objective was to develop a cost-effective cement-based material with high strength and toughness, suitable for underground coal mines. The experimental results demonstrate that the self-developed cement-based materials exhibit rapid setting, excellent fluidity, high early strength, and strong durability compared to traditional alternatives. Analyses of the comprehensive properties reveal that the influencing factors, in order of significance, include the mass ratio of cement and sand, water cement ratio, rubber content, and bonding mortar master material content. By employing extreme treatment and efficiency coefficient methods, the comprehensive performance of materials under different ratios was evaluated. Consistent findings were obtained, indicating that the optimal mass ratio of cement-based materials is 500:500:20:15:10:5:8:10 for cement, sand, fly ash, silica fume, mineral powder, steel slag powder, bonding mortar master material, and rubber, respectively. Additionally, the best comprehensive performance was achieved with a water cement ratio of 0.5, which confirms the results of the orthogonal test. Macroscopic failure characteristics and SEM microscopic analysis further validate the superior performance of the materials under the aforementioned ratio. The reaction process of the material can be roughly divided into four stages: initial hydrolysis stage, induction stage, acceleration stage, decay and stability stage, and finally the formation of stone body. A comparison with ordinary materials highlights the advantages of the developed cement-based materials, and suggestions are proposed for the development of field-applicable materials.

Research on the production technology of rubber epoxy from concentrated natural rubber latex

The results of research on epoxidation technology from concentrated natural rubber latex (CNRL) and in-situ peroxyformic acid, which is synthesised from formic acid (FA) and hydrogen peroxide (HP), are presented in the article. The study investigated the influence of technological parameters of the epoxidation process, such as stabiliser content (nonylphenol ethoxylate, NP9), dry rubber content (DRC), isoprene, stirring speed, reaction time, reaction temperature, and molar ratios of hydrogen peroxide and isoprene (IP), on the epoxy resin content of the product. Research results have shown that the epoxidation reaction with NP9 at 10% takes from 2.5 to 20 hours under the following conditions: latex composition contains from 16 to 24% DRC, stirring speed 100 rpm, reaction temperature response 30 to 70 °C, HP/IP molar ratio changes from 0.7 to 1.3, FA/IP ratio is 0.2, the product was stable and without coagulation. The product was obtained with an epoxy content of 23.4 to 43.6%. This is the basis for building an epoxidized natural rubber (ENR) production process to create a series of natural rubber products that are renewable, environmentally friendly, low-cost, and have many industrial applications.

Rapid Determination of Taraxacum kok-saghyz Rubber Content Using a Pyrolyzer Hyphenated with a Miniaturized Mass Spectrometer

Taraxacum kok-saghyz (TKS), a rubber-producing plant with excellent potential, emerges as a viable substitute for rubber tree (Hevea brasiliensis). While natural rubber is a desirable material, conventional techniques for assessing rubber content have faced challenges in meeting practical production requirements. To address this issue, we have developed a pyrolysis–mass spectrometry (PY-MS) instrument for the quantitative evaluation of natural rubber (NR) content in rubber-producing plants. The derived standard curve equation, established for the detection of TKS dry weight through external standard calibration, demonstrates a correlation coefficient (R2) surpassing 0.99. The method exhibits commendable recovery rates (93.27–107.83%), relative standard deviations (RSD ≤ 3.93%), and a swift analysis time of merely 10 min per sample, thereby enabling accurate and efficient quantification of NR dry weight. Additionally, the PY-MS system we designed can be modified for vehicular use, enabling on-site, in situ analysis, and it provides substantial support for TKS breeding and propagation efforts. This approach possesses significant potential for extensive utilization in the assessment of rubber content in rubber-producing plants other than TKS. The integration of pyrolysis–mass spectrometry for the identification of polymers with high molecular weight offers a valuable pathway for the examination of diverse polymers.

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.