Asphalt Content Research Articles

Assessing the Mechanical Properties of Open-Graded Asphalt Mixtures

In consideration of the escalating vehicular intensity and the substandard material properties of pavements in Iraq, particularly with regard to their impact on wet-weather accident rates and noise pollution in urban areas, there is an urgent need for an analysis of Open-Graded Asphalt (OGA) mixes to address the environmental and safety concerns. While OGA mixtures offer the dual advantages of reducing stormwater runoff and enhancing wet skid resistance, they are also more prone to raveling due to their high porosity. To enhance the performance of OGA mixes, various methods have been employed, including the incorporation of recycled polymers. The primary objective of this research is to evaluate the durability and strength properties of OGA mixes through laboratory testing using the Recycled Polyvinyl Chloride (RPVC) polymer. Laboratory tests were conducted on OGA mixes to ascertain the Marshall stability, resistance to abrasion, permeability, tensile strength, and moisture-induced damage. The mix designs were executed in accordance with the design procedure proposed by the National Cooperative Highway Research Program (NCHRP) for a range of 5.5%–7.0% asphalt content. RPVC was used in various proportions (2%, 4%, 6%, and 8%) by the weight of the base binder. The experimental findings demonstrated that the incorporation of RPVC led to enhanced Marshall stability and Indirect Tensile Strength (ITS) in porous asphalt concrete, surpassing the performance of conventional asphalt mixes. Additionally, the OGA mixture exhibited significant improvements in raveling resistance and moisture susceptibility. The study concluded that the Optimal Binder Content (OBC) of RPVC could enhance the pertinent engineering properties of OGA mixtures without compromising their permeability.

Performance Evaluation of Magnesia-Type Refractory Brick Waste as Complete Replacement for Fine Aggregate and Filler in Asphalt Concrete Wearing Course Mixtures

Infrastructure development has been rapidly increasing in recent times, and the use of waste materials as aggregates in this process has positively impacted regional and national economies. This study investigates the use of magnesia-type Refractory Brick (RB) waste as a substitute for fine aggregate and filler in Asphalt Concrete-Wearing Course (AC-WC) mixtures. The RB waste is generated from the kiln walls of nickel smelting furnaces and is used to completely replace natural sand by weight. The study compared Marshall empirical values, such as stability, yield, and Marshall quotient (MQ), volumetric characteristics, such as Void In the Mix (VIM), Void in Mineral Aggregate (VMA), and Void Filled with Bitumen (VFB), and Ultrasonic Pulse Velocity (UPV) of AC-WC mixtures containing natural sand at asphalt percentages of 5.0%, 5.5%, 6.0%, 6.5%, and 7.0%. The findings reveal that the optimum Marshall properties were achieved with RB waste at a 5% asphalt content, compared to 6.0% for natural sand. Furthermore, the AC-WC mixture incorporating RB waste exhibited sufficient strength and durability to withstand traffic loads, suggesting that the complete replacement of natural sand with RB waste significantly influences the properties of AC-WC asphalt, promoting the environmentally friendly and economical reuse of waste materials in the industry.

Performance of Asphalt Concrete Mixtures Containing Nickel Slag

Recent advancements in material technology have led to an increased interest in using alternative materials in the asphalt mixtures. One such material is Nickel Slag (SN), a byproduct of nickel ore smelting. With the growing volume of slag produced during nickel smelting, research has focused on using SN as a component in pavement materials to reduce the steel waste accumulation. The primary objective of this study is to explore the optimal use of SN as a coarse aggregate in asphalt concrete mixtures, aiming to achieve the maximum asphalt content. The study also evaluates the impact of SN on the stability, volumetric characteristics of the asphalt mixtures, and Ultrasonic Pulse Velocity (UPV) wave patterns. The research involved Marshall testing using a Universal Testing Machine (UTM) and UPV testing. The results indicated that SN mixtures reached maximum stability at 5.8% asphalt content and demonstrated higher stability values than conventional mixtures. As a coarse aggregate replacement, SN enhances the resistance to permanent deformation due to its hardness, interlocking properties, and the silica content that improves adhesion to the asphalt. Incorporating SN into asphalt mixtures improves mix stability, reduces industrial waste, conserves natural resources, and enhances road infrastructure quality. This method supports the principles of sustainable development.

Assessing the Influence of Brick Powder as Filler in Asphalt Hot Mixes

This study investigated the efficacy of utilizing waste Brick Powder (BP) as a partial or complete replacement for the filler in Hot Asphalt Mixes (HAM). BP was used to substitute Portland Cement (PC) in varying proportions: 25%, 50%, 75%, and 100%. The mixes were evaluated based on Marshall properties, Indirect Tensile Strength (ITS), and Tensile Strength Ratio (TSR). The findings revealed increased Marshall stability, stiffness, and ITS in the mixes containing BP. The flow decreased for HAM containing BP, particularly for those with a complete replacement of cement having utilized BP as the filler, indicating an improved ability of the HAM to withstand loads. The tests conducted at 25, 40, and 60 °C showed that the ITS increased steadily with an increased BP proportion, which is beneficial for rutting resistance, as high service temperatures influence rutting, and high ITS corresponds to a longer rutting life of the asphalt mix. The effect of improving the tensile strength at 60 °C was higher than at 25 °C and 40 °C. Additionally, the BP mixes demonstrated greater resilience to moisture effects compared to the reference mix. The use of BP as an alternative filler for PC did not significantly impact the volumetric properties of the HAM. It was determined that BP could be successfully added to the HAM at a 100% replacement rate as a filler, with an ideal asphalt content of 5.6%. The results suggest that the processing and management of waste bricks can be a sustainable development strategy.

Marshall Properties and Rutting Resistance for Asphaltic Mixtures Modified by Nano-Montmorillonite

Rutting is a significant problem in flexible asphalt pavements, causing permanent deformation. Increased traffic, axle load, tire pressure, and hot weather have recently accelerated rutting in flexible pavements. Several researchers have suggested using nanomaterials to improve asphalt pavement and prolong its lifespan. The nano clay chosen for this study is a natural, hydrophilic montmorillonite in its raw form. Consequently, incorporating Nano-montmorillonite (MMT) into asphalt mixtures to improve performance under dynamic loads has gained significant attention. This can help reduce rutting damage and ensure the safety and durability of road surfaces. This study examines the impact of incorporating MMT into hot mix asphalt on the Marshall properties and resistance to rutting. It involved determining the optimal asphalt content using the Marshall design method, as well as the rutting depth for asphalt mixes using wheel tracking tests, for mixtures comprising different MMT percentages (2%, 4%, and 6%) as a percentage of the asphalt binder. The optimal asphalt content was 4.93% for the control mix. The inclusion of 6% MMT increased the Marshall stability the most by 16.79%. Marshall flow decreased when MMT was added. The control mix had a Marshall flow of 3.30 mm, but when using 4% MMT, the flow decreased to 2.81 mm, the most significant reduction. The ideal proportion of MMT was 6%, resulting in a 39.79% reduction in rut depth compared to the control mixture.

Research on the Correlation Between the Chemical Components and the Macroscopic Properties of Asphalt Binder

The chemical composition of asphalt binder is closely related to its macroscopic properties, and as an important road building material, its performance directly affects the service performance of asphalt binder pavement. Saturate, aromatic, resin, and asphaltene are the four most common chemical components of asphalt binders, collectively known as the SARA components. The SARA components are used to establish the corresponding relationship between the chemical composition and the macroscopic properties of asphalt binder, which is of great significance for further research on and development of high-performance asphalt pavement materials. This study used eight types of virgin asphalt binders as raw materials, labeled A–H. Firstly, the thin-layer chromatography–flame ionization detection (TLC-FID) method was used to test the SARA contents of the different asphalt binders. Then, the conventional, rheological, and low-temperature properties of the different binders were tested. Finally, gray relational analysis (GRA) and Pearson correlation analysis (PCA) were used to study the correlation between the asphalt binder’s SARA content and its macroscopic properties. The results indicate that the contents of asphaltenes and resins are crucial in determining the high-temperature performance of asphalt binder. By adjusting the ratio of these components, the high-temperature performance of asphalt binder can be optimized. An increase in the content of heavy components, particularly asphaltenes, negatively affects the low-temperature performance of asphalt binder. In contrast, a higher aromatic content enhances its low-temperature performance.

Analisis Karakteristik Aspal Berdasarkan Batuan Reservoir Kabupaten Buton Provinsi Sulawesi Tenggara

Factors influencing the content of asphalt is the process of formation, moisture content and the type of reservoir rocks, then to do the research on the characteristics of asphalt based on reservoirnya rocks. The purpose of this research is to know the physical nature of Asphalt Buton Rock based on reservoirnya. The method used is the sokhlet method. The data used is data of rocks reservoir site I and II, the physical properties of the data of the asphalt. Of research results obtained at the location I have rocks limestone reservoir with poor porosity features have higher levels of bitumen (23-47%), the asphalt is more dense and hard, CaCO3 content was higher (86,66%) whereas in a location that has a reservoir rock II sandstones with physical characteristics of good porosity have lower levels of bitumen (20-40%), the asphalt is relatively more malleable, a higher SiO2 content (17,06). From the results it can be concluded that the physical nature of asphalt location I have poor porosity and physical properties II location has good porosity, on the location of research levels obtained 20-47%.

The Effect of Addition of Sugarcane Ash Waste and Low Density Polyethylene Plastic on the Characteristics of Laston AC-WC Mixture

Bagasse ash has pozzolanic properties which contain chemical compounds in the form of Silica (SiO2) and act as fillers and Low-Density Polyethylene (LDPE) plastic has the same plastomer properties as asphalt thermoplastic properties. Both of these wastes can be used as substitute materials for the Laston AC-WC mixture. This exploration aims to determine the effect of adding sugarcane bagasse ash and LDPE plastic on the characteristics of the Laston AC-WC mixture. The variations in the levels of bagasse ash added were 25%, 50%, 75%, and 100% of the filler weight and LDPE 5%, 5.55%, and 6% of the total asphalt weight. After the Marshall test was carried out, the Laston AC-WC mixture with the addition of bagasse ash and LDPE could increase the stability value compared to the asphalt mixture without the addition of waste. The optimum asphalt content value is found in a mixture of 75% bagasse ash and 6% LDPE content because it has the highest stability value and other Marshall test values ​​are in accordance with the 2019 Hot Asphalt Mix Design and Implementation Guidelines for Utilizing Plastic Waste.

Non-Linear Support Vector Machine Prediction of the Mechanical Properties of Asphalt Binders Subjected to Varying Temperatures and Frequencies Based on SARA

This study investigates the effects of chemical fractions on the mechanical properties of asphalt binders and predicts the mechanical properties of asphalt binders based on the chemical fractions. Initially, four fractions—saturate, aromatic, resin, and asphaltene (SARA)—were isolated from 36 asphalt binders using a thin-layer chromatography with flame ionization detection (TLC-FID) analyzer. Subsequently, the complex modulus and phase angle of the asphalt binders were determined for a range of frequencies and temperatures. The relationships between SARA content, heavy components, colloidal instability index, and the complex modulus and phase angle were analyzed. Advanced models, including quadratic polynomial and non-linear support vector machine (SVM) with sigmoid and RBF (Gaussian) kernels, were employed to predict the complex modulus and phase angle of asphalt binders based on the SARA data, and the reliability of these prediction models was critically assessed. The findings indicate that the contents of asphaltenes, resins, aromatics, and saturates significantly influence the rheological properties at different frequencies, though a clear correlation between SARA contents and both the complex modulus and phase angle was not established. Alternative methods should be considered for studying the mechanical properties of asphalt derived from SARA. The RBF kernel demonstrated superior performance compared to the quadratic polynomial and non-linear SVM with the Sigmoid kernel. While the non-linear SVM with the RBF kernel accurately predicts the complex modulus, it fails to predict the phase angle at low frequencies. The validation of this model confirmed its efficacy in capturing the relationship between input (SARA) and output (complex modulus and phase angle) vectors for each asphalt binder. The predicted complex modulus master curves closely match the experimental results, yet the model only approximates the trend of phase angle variation with frequency.

Performance optimization of asphalt pavements using binder film thickness as a criterion in innovative mix design compared to Marshall and Superpave methods

The performance of asphalt pavements is significantly influenced by the mix design and the binder film thickness (BFT) around aggregates. Adjusting the proportions of binders and aggregates modifies the properties of asphalt mixtures, with different mix designs substantially impacting these properties. This study evaluates the influence of two traditional mix designs (i.e., Marshall and Superpave Gyratory Compacted) and one innovative mix design (the one using BFT as a criterion) on asphalt pavement performance Two methods, which are modifications of the Hveem Surface Area Factor method, were used to calculate the optimum BFT. The mix with 3.5% asphalt content (AC) was selected for the innovative mix design as it showed the optimal BFT. For the Marshall and Superpave mix designs, the optimum binder content was determined using the respective Marshall and Superpave Gyratory Compacted methods, yielding values of 4.3% and 4.4%, respectively. Samples were prepared from each type of mix design and then tested using a Universal Testing Machine (UTM) and a Double Wheel Tracker (DWT). Performance tests showed that the innovative mix design samples had superior rutting resistance under DWT, the Marshall samples had the highest Resilient Modulus (Mr) and moisture resistance, and the Superpave samples exhibited the best fatigue resistance, enduring the most cycles until failure in the Indirect Tensile Fatigue Test (ITFT). These findings underscore the importance of considering BFT as a critical mix design criterion, demonstrating its significant potential to enhance the overall performance and durability of asphalt pavements.

Enhancing Asphalt Durability with Styrofoam and Coconut Shell Ash: Evaluating Resistance to Diesel Fuel Spills

Abstract This study aims to determine the optimal percentage of Styrofoam and Coconut Shell Ash (CSA) in the Asphalt Concrete-Wearing Course (AC-WC) mixture to mitigate the impact of diesel fuel spills on asphalt quality, addressing the degradation of asphalt due to accidental diesel fuel spills that compromise road durability. The research employed Marshall parameter testing following Bina Marga 2018 General Specifications, Revision 1 of 2019 (Division 6). Five asphalt content variations were used (4.5%, 5%, 5.5%, 6%, and 6.5%), with two substitution levels for Styrofoam (6% and 8%) and two for CSA (50% and 100%). The impact of diesel fuel immersion was simulated with immersion times of 5 and 9 minutes. The optimal asphalt content (OAC) was found to be 5.5%, producing favorable characteristics with a stability value of 3,868.26 kg, while the combination of 8% Styrofoam and 50% CSA filler yielded the best performance with a stability value of 4,817.28 kg. Immersion testing of this mixture with diesel fuel for 5 minutes (4,212.64 kg) and 9 minutes (3,874.08 kg) also produced stability values well above the required threshold of > 1,000 kg. The results demonstrate that using 8% Styrofoam and 50% CSA filler can significantly improve the mixture’s resistance to degradation from diesel spills. This study provides significant insights into the potential of using polymer waste materials to enhance the durability of asphalt roads, promoting the reuse of waste and improving road infrastructure resilience.

Effect of Filler Types on Moisture Damage of Asphalt Mixtures

The filler in the asphalt mixture is essential since it plays a significant role in toughening and stiffening the asphalt. Changes in filler type can lead the asphalt mixtures to perform satisfactorily during their design life or degrade rapidly when traffic and environmental effects are considered. This study aims to assess the impact of filler types such as limestone dust (LS) and hydrated lime (HL) on Marshall characteristics and moisture damage in asphalt mixtures. Three different percentages of HL were employed in this study to partially replace the LS mineral filler: 1.5, 2.0, and 2.5% by aggregate weight. Furthermore, a control mixture was created with 7% LS by overall aggregate weight for the wearing course layer. The Marshall method was used to obtain the optimal asphalt content and the asphalt mixes' volumetric properties. The optimum asphalt content was used to prepare the asphalt concrete mixes, which were then tested for moisture damage resistance using the indirect tensile strength (ITS) and the index of retained strength (IRS). The findings demonstrate that resistance to moisture damage can be significantly enhanced by partially substituting HL for the LS filler. This was verified by the fact that the optimum increase in the tensile strength ratio (TSR) was 7.29% at 2.5% of HL, and at the same HL percent, the greatest rise in the IRS was 9.81% compared with the control mix.

Investigating the Moisture Susceptibility Resistance of Asphalt Mixes Modified with Silica Fume Additive

Moisture induced damage is a prevalent pavement distress commonly observed by road agencies. The damage caused by moisture significantly affects the pavement's lifespan and performance. This research investigated the influence of silica fume (SF) on the susceptibility to moisture. Three concentrations of silica fume were used 3%, 6%, and 9% by weight of the binder. A thermal camera has been used to detect variations in homogeneity in the modified asphalt during the mixing process. The optimal asphalt content was 4.92, 5.02, 5.16, and 5.22 for the control and modified mixtures. The moisture susceptibility was evaluated by measuring the tensile strength ratio (TSR) and index of retained strength (IRS). The thermal images showed that the silica fume particles in the mixture were uniformly distributed, as indicated by the convergence of colors at 160°C. The findings showed that the inclusion of SF at 6% decreased sensitivity to moisture, corresponding to an increase in TSR and IRS of 12.49% and 13%, respectively.

Experimental Study on Porous Asphalt Mixtures with Hybrid Substitute Materials

Abstract The growing challenges of environmental sustainability and waste management in the construction industry have spurred the search for innovative materials to enhance asphalt mixtures. Conventional porous asphalt faces limitations in durability and performance under varying traffic and weather conditions. Moreover, the disposal of oyster shells and High-Density Polyethylene (HDPE) waste poses significant environmental concerns. This study evaluates the effect of oyster shell ash (OSA) as a filler and HDPE waste as an asphalt substitute in porous asphalt mixtures. Testing was conducted to determine the Optimum Asphalt Content (OAC) based on three primary parameters: Cantabro Loss (CL), Void In Mix (VIM), and Asphalt Flow Down (AFD). The results indicate that the OAC value is 5.8%. In the Void In Mix (VIM) test, the best results were obtained with a variation of 50% OSA: 50% PC and 4% and 6% HDPE, yielding VIM values of 18.49% and 18.16%, respectively, which meet the AAPA (2004) standard requirement of 18-25%. The Asphalt Flow Down (AFD) test results showed that the same mixture produced AFD values of 0.09% and 0.10%, well within the maximum limit of 0.3%. The optimal values for the Cantabro Loss (CL) parameter were also achieved with the same combination, resulting in 32.67% and 30.07%, which comply with the maximum threshold of 35%. This study concludes that the combination of oyster shell ash (50% OSA: 50% PC) and HDPE (4% and 6%) performs well in porous asphalt mixtures, meeting the standards for durability, strength, and stability in road pavement applications.

Simulation of The Backpropagation Method on Durability Value Using Starbit Asphalt Against Soaking Time

Starbit is a kind of celestial object elastomeric polymer asphalt that has been given additives. The advantages Starbit Asphalt are that it has high resistance to temperature and deformation and has good adhesion and cohesion. The purpose of this research is to calculate the durability value and try to use simulation. The research methodology encompasses simulating the backpropagation method and performing an experimental investigation in a tightly controlled laboratory setting. involves conducting an experimental investigation in a controlled laboratory setting. The durability testing encompasses different periods of time, such as thirty minutes, twelve hours, forty-eight hours, sixty-two hours, and ninety-six hours. The test results yielded an optimum asphalt content of 6.19%, which will be utilized for the production of durability samples. The test findings indicate that the durability value satisfies the criteria set by the 2018 Bina Marga Specification revision 2, which requires a minimum of 90% durability. Therefore, the material meets the durability requirements and can be utilized. After testing, the backpropagation method is simulated with stability values. The simulation results with the backpropagation method obtained the durability value with a maximum error value of 0.16% and the smallest value of -0.0068% error. So it can be concluded that the backpropagation method is considered capable of predicting durability values with an error of less than 50%. To obtain maximum results in further research, it is recommended to use.

Pengaruh Penggunaan Plastik LDPE (Low Density Polyethylene) Sebagai Substitusi Aspal dan Serbuk Kaca Sebagai Substitusi Filler pada Campuran LASTON AC-WC

Road deterioration is a common problem in Indonesia, influenced by population growth, the number of vehicles, and environmental factors. LASTON (Asphalt Concrete Layer) is a type of flexible pavement consisting of a mixture of asphalt, aggregate, and filler, which requires innovation to improve its quality. The objectives of this study were to determine the marshall parameters of LASTON AC-WC mixtures added with LDPE plastic and glass powder variations, obtain the KAO (Optimum Asphalt Content) value, and find the price efficiency of Conventional LASTON AC-WC mixtures and Innovative LASTON AC-WC. The research method used was an experimental test at the Civil Engineering Laboratory of Diponegoro University Vocational School, referring to the 2018 Bina Marga standard (Revision 2). This study designed 15 samples to obtain the KAO value so that the KAO obtained from the marshall test calculation was 5.5%, as well as 27 samples to determine the optimum content of LDPE plastic and Glass Powder with variations in LDPE plastic content of 4%, 5%, and 6% by weight of asphalt and Glass Powder content of 25%, 50%, and 75% by weight of fillers. The variations were tested using hot asphalt mixtures' stability and flow test methods with marshall test equipment referring to the 2018 General Specifications. This study obtained the optimum percentage of LDPE 5% and Glass Powder 75%, which met the requirements of the 2018 General Specifications. The marshall test results show the BJ Bulk value of 2.399 T/m3, VIM 4.901%, VMA 14.063%, VFA 70.393%, Stability 2029.455 kg, Flow 2.297 mm, and MQ 868.783 kg/mm. The cost of conventional asphalt mixture material is Rp 1,046,123, while the cost of innovative asphalt mixture material is Rp 987,017; thus, the innovative asphalt mixture material is more economical, with a price difference of Rp 59,105.90/ton.

Cement Kiln Dust as Substitute Fillers for Hot Mix Asphalt

To reduce construction costs, eliminate environmental issues, and protect natural resources, waste and by-product materials are frequently substituted for raw components in asphalt mixtures. This study investigates the feasibility of employing cement kiln dust (CKD), which is abundantly available in various regions of Yemen, as substitute hot mix asphalt filler (HMA) for conventional fillers. A traditional filler, basalt filler (BF), was partially and totally replaced at different percentages of CKD with 25%, 50%, 75%, and 100% by weight of fillers. The evaluation of the planned HMA was done using conventional mechanical and volumetric characteristics. A total of 15 bituminous concrete mix specimens with bitumen content of 4%, 4.5%, 5%, 5.5%, and 6% were created, and the optimum asphalt content was 5.24 %. The impacts of four different (CKD) samples with filler contents of 25%, 50%, 75%, and 100% by weight were compared with respect to bituminous concrete performance. The outcomes of the experiment demonstrated that CKD may substitute 75% of the BF at a bitumen content of 5.24%, 13.76 KN Marshall stability value, 4.02% air voids, 75 % VFB, 2.370 g/cm3 bulk density and 2.57 mm flow. Therefore, incorporating CKD as fillers in HMA is a sustainable solution that enhances performance, durability, and environmental benefits in road asphalt construction.

Enhanced mechanical properties of alkali-activated dolomite dust emulsified asphalt composites

The dolomite dust-emulsified asphalt composite (DAC) with excellent mechanical properties was successfully prepared using alkali activation. The effects of different alkali concentrations and emulsified asphalt contents on the mechanical properties of the materials were studied. And the micro-mechanisms of its mechanical performance changes were analyzed through SEM and XRD characterization. The experimental results show that the specimens have excellent mechanical properties: the 7-day compressive strength can reach 76.67 MPa, and the bending and compressive strength ratio is about twice that of silicate-based geopolymer-emulsified asphalt composite (SAC). With an increase in emulsified asphalt content, the compressive strength of the samples decreases, while the bending strength increases first and then decreases. When the emulsified asphalt content is 1%, the bending strength of the sample is up to 28.81 MPa, which is 25% higher than that of the sample without emulsified asphalt. The in-situ formation of calcium carbonate crystal clusters within the DAC was suggested that may support this performance. This crystalline structuring contributes to an expanded interfacial contact area between the asphalt and skeleton particles, thereby enhancing the demulsification and bonding properties of the emulsified asphalt. This indicates that an appropriate emulsified asphalt content can play a toughening role in the system, providing a new idea for designing high-toughness alkali-activated materials.

Quinoline impact on composition, structure and aggregative stability of asphaltenes from heavy oil of different chemical types

Relevance. The need to establish the true mechanisms of the formation of supramolecular structures in petroleum dispersed systems. It is important to identify the role of individual functional groups in asphaltene aggregation. This will help develop effective ways to prevent sediment formation in process equipment during production, transportation and processing of heavy oils. Aim. To study the effect of quinoline on the composition, structure and aggregative stability of asphaltenes from heavy oils of various chemical types. Objects. Heavy oils from the Zyuzeevskoe field and the Usinskoe field; model petroleum systems with a basic nitrogen content of 1,0 to 3,0 wt %; asphaltenes of the original and model petroleum systems. Methods. Liquid adsorption chromatography, gas chromatography-mass spectrometry, potentiometric titration, elemental analysis, cryoscopy in naphthalene, 1H NMR spectroscopy, structural group analysis, spectrophotometry. Results. With an increase in Nbas concentration in an petroleum system to 3 wt %, the content of asphaltenes decreases regardless of the type of petroleum system. It has been established that quinoline is actively involved in the formation of supramolecular structures of naphthenic type oil. With an increase in the Nbas content in the naphthenic petroleum system to 3 wt % the molecular weight of asphaltenes increases 1,5 times with a 2-fold increase in the proportion of basic nitrogen in their composition. This is accompanied by an increase in the proportion of naphthenoaromatic structure in the average asphaltene molecule. The structure of asphaltenes isolated from model methane-type petroleum systems, on the contrary, is enriched in alkyl fragments. It wasn established that the presence of quinoline in asphaltenes of heavy oils as a coprecipitated component significantly reduces their aggregative stability. With an increase in the molecular weight of asphaltenes in naphthenic petroleum systems to 2000 amu. and the proportion of basic nitrogen up to 2,69 wt % the rate of their aggregation before precipitation is reduced by 5–6 times. The aggregative stability of methane oil asphaltenes decreases when Nbas content in their composition is higher than 1,9 wt % and does not depend directly on their molecular weight.

Optimizing Thermosetting Epoxy Asphalt with Styrene–Butadiene Rubber and Styrene–Butadiene–Styrene Modifiers for Enhanced Durability in Bridge Expansion Joints

The high- and low-temperature performance of asphalt-based seamless expansion joints seriously affects road performance. The purpose of this paper is to explore the application of thermosetting epoxy asphalt-based materials in bridge expansion joints. The composite modification of asphalt was performed using Styrene–Butadiene rubber (SBR) and Styrene–Butadiene–Styrene (SBS) copolymer. The study then investigates the impact of five different dosages of SBR/SBS-modified asphalt on the performance of epoxy asphalt. The results of the cone penetration test, tensile test, and stress relaxation test of SBR/SBS-modified epoxy asphalt (SSEA) and BJ200 (a commercial Seamless expansion joint material) were comparatively analyzed. The Marshall test, rutting test, three-point bending test, and freeze–thaw split test were used to evaluate the road performance of SSEA mixtures. The test results show that with the increase in asphalt content, the shear resistance and tensile strength of SSEA decrease, and the low-temperature relaxation ability and elongation at break increase. The content of SBR/SBS-modified asphalt has a positive effect on the low-temperature performance of SSEA mixtures, and the residual stability in water and freeze–thaw splitting strength ratio (TSR) are higher than that of BJ200. Based on the requirement of balancing high and low-temperature performance, SSEA-3 has the best overall performance, and the dosage of SBR and SBS modifier is 12% and 2.5%, respectively. The ratio of epoxy resin, SBR/SBS-modified asphalt, and the curing agent is 1:4:1.6, and its use is recommended in areas with slight temperature differences.