Search Results (215)

This paper discusses the efficiency of ultrasonic-assisted bitumen extraction from bituminous sands of the Beke deposit (Mangistau region, Kazakhstan) using alkaline aqueous solutions. The process parameters, including ultrasonic frequency (22 kHz), power (up to 1500 W), solution pH (>12), and optimal NaOH concentration (1 wt.%) were optimized to achieve a maximum bitumen recovery of 98 wt.% within 8 min. The most effective sand-to-solution mass ratio was determined as 1:2, while the optimal process temperature was 75 °C. The application of ultrasound significantly enhances cavitation and reagent penetration, enabling efficient separation of bitumen with minimal chemical usage. Fourier-transform infrared (FTIR) spectroscopy and GC–MS analyses revealed the presence of aromatic hydrocarbons, paraffinic and naphthenic structures, as well as sulfur- and oxygen-containing functional groups (e.g., sulfoxides, carboxylic acids). These characteristics suggest moderate maturity and a high degree of aromaticity of the organic matter. Despite suitable thermal and compositional properties, the extracted bitumen exhibits a relatively low stiffness and softening point, indicating the need for additional upgrading (e.g., oxidation) prior to use in road construction. Although standard rheological tests (e.g., dynamic shear rhinometry) were not conducted in this study, the penetration and softening point values suggest a relatively soft binder, possibly unsuitable for high-temperature paving applications without modification. Future research will focus on rheological evaluation and oxidative upgrading to meet the ST RK 1373-2013 specification requirements. Full article

Many transportation structures collapse or sustain severe damage as a result of natural disasters such as earthquakes, floods, wars, and similar attacks. These collapsed or severely damaged structures must be rebuilt and returned to service as quickly as possible. Water is used in the mix for cement-bound concrete roads. It is known that drought problems are emerging due to climate change and that water resources are rapidly depleting. Significant amounts of water are used in concrete production, further depleting water resources. In order to contribute to the elimination of these two problems, the usability of polyurethane resin binder in road pavement construction was investigated. Polyurethane resin binder road pavement is a new type of pavement that does not contain cement or bitumen as binders and does not contain water in its mixture. This new type of road pavement can be opened to traffic within 5–15 min. After determining the aggregate and binder mixture ratios, four different curing methods were applied to the created samples. After the curing, the samples were subjected to compression test, flexural test, Bohme abrasion test, freeze–thaw test, bond strength by pull-off test, ultrasonic pulse velocity (UPV) test, SEM-EDX analysis, XRD analysis, and FT-IR analysis. The new type of road pavement created within the scope of this study exhibited a compression strength of 41.22 MPa, a flexural strength of 25.32 MPa, a Bohme abrasion value of 0.99 cm³/50 cm², a freeze–thaw test mass loss per unit area of 0.77 kg/m², and an average bond strength by pull-off value of 4.63 MPa. It was observed that these values ensured the road pavement specification limits. Full article

The article presents the results of a study on 50/70 paving-grade bitumen modified with the bitumen recovered from two types of asphalt shingles: post-consumer asphalt shingles (TOAS) and manufacturing waste asphalt shingles (MWAS) at three dosage levels (15%, 30%, and 45% w/w). The evaluation included the basic properties of bitumen—its penetration and softening point—as well as rheological properties, such as its viscosity, fatigue life determined by the LAS method, and rutting resistance assessed using the MSCR test and FTIR analysis. In both cases, the results showed that an increase in the stiffness of the base bitumen was observed. An improvement in rutting resistance was also recorded, as evidenced by the reduction of J_nr3.2, along with an increase in fatigue life. A stronger stiffening effect was found in the case of the TOAS-derived bitumen, which is related to aging processes occurring during its service life. This suggests that the maximum allowable content of the additive should depend on the source of the reclaimed asphalt shingles, with MWAS being applicable in larger amounts without excessive deterioration of bitumen performance. The key contribution of this study is the demonstration that the MWAS and TOAS additives cannot be treated equally, as each affects the base bitumen differently. Full article

The durability of asphalt pavements is crucial for sustainable road infrastructures. This systematic review compares the Marshall and Superpave asphalt mix design protocols, with a particular focus on the integration of polymer-modified bitumen (PMB) and rejuvenators. Although the Marshall method remains widely used for its simplicity and cost-efficiency, its empirical basis limits its effectiveness to meet modern pavement performance demands. In contrast, the Superpave system offers improved resistance to rutting, longer fatigue life, and better mitigation of moisture damage. The review traces the evolution of asphalt mix design, identifies current challenges, and emphasizes the need for transitioning toward performance-based frameworks. Special attention is given to the incorporation of polymers such as Styrene–Butadiene–Styrene (SBS), Styrene–Butadiene–Rubber (SBR), and Polyethylene (PE), which significantly enhance the mechanical properties of asphalt mixtures. The role of rejuvenators in restoring aged binders and enabling pavement recycling is also examined. Finally, the manuscript provides strategic recommendations for adopting Superpave to enhance pavement durability and reduce lifecycle maintenance costs. Overall, this comprehensive review advances knowledge on asphalt mix design, fostering innovation and sustainability while promoting long-term resilience in road pavement infrastructures. Full article

The study investigates the interaction of humic acids (HAs) with road petroleum bitumen to enhance its performance and resistance to technological aging. It addresses a critical gap in understanding the modification mechanisms. The research is motivated by the need for sustainable and effective bitumen modifiers to improve the durability of asphalt pavements. The primary objective was to characterize the interaction between HA and bitumen using advanced analytical techniques, including complex thermal analysis (DTA/DTG), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results demonstrated that adding two wt.% HA to bitumen BND 70/100 increased its thermal stability, raising the onset temperature of thermo-oxidative processes from 214 to 237 °C and reducing the mass loss rate during heating from 2.5 to 1.9%·min⁻¹. FTIR analysis revealed chemical interactions between polar groups of humic acids (e.g., –COOH, –OH) and bitumen components, forming a denser structure. SEM images confirmed a more homogeneous microstructure with fewer microcracks in the modified bitumen. Practical improvements included a higher softening point (52.6 to 54 °C) and enhanced elastic recovery (17.5 to 28.7%). However, the study noted limitations such as reduced ductility (from 58 to 15 cm) and penetration (from 78 to 72 dmm), indicating increased stiffness. The findings highlight the potential of humic acids as eco-friendly modifiers to improve bitumen’s aging resistance and thermal performance, offering practical value for extending pavement lifespan. The effective use of HA will, in turn, allow the use of Ukrainian lignite, the balance reserves of which are estimated at 2.0–2.9 billion tons, in non-fuel technologies. Full article

Energy demand is a critical challenge for sustainable infrastructure, yet in road asset management, it is rarely considered a central decision criterion. Most decision frameworks remain focused on financial and structural performance. This study introduces a comparative Energy Balance Analysis (EBA) as a complementary tool to existing life-cycle approaches. A case study is presented in which the only variable is binder composition—conventional 50/70 bitumen versus the same binder modified with 3% styrene–butadiene–styrene (SBS) polymer. The methodology integrates material-level energy demand estimation, laboratory performance testing, and pavement life modeling with HDM-4, and vehicle operational energy analysis. Results show that although SBS modification increases initial binder production energy by 13.3%, it doubles pavement service life and avoids mid-life rehabilitation, leading to a net saving of 110,671.75 MJ over 20 years. These findings confirm that early-stage material improvements can generate long-term energy efficiency gains. The study thus demonstrates the potential of EBA as a practical decision-support tool for sustainable pavement management. Full article

The use of mining by-products in bitumen and asphalt mixture modification has drawn a lot of interest lately since it can improve pavement performance while advancing the goals of the circular economy and environmental sustainability. Mining by-products such as steel slag, red mud, silica fume, and fly ash have demonstrated good results as sustainable materials for improving the chemical, mechanical, durability, and rheological properties of asphalt binders and mixtures while also reducing the environmental degradation brought about by the disposal of these by-products. This study reviews research efforts on mining by-products (specifically steel slag, silica fume, red mud, and fly ash) in asphalt concrete pavement construction, analyzing the existing research, with emphasis on their various applications in asphalt concrete, their benefits as sustainable asphalt concrete materials, and limitations connected to their use. This review concludes by providing future directions in the utilization of these mining by-products in asphalt concrete production. This review contributes to the development of cost-effective, eco-friendly, and high-performance road construction materials, helping the transition to sustainable infrastructure. Full article

The growing emphasis on sustainable road construction has stimulated interest in environmentally friendly bitumen modifiers. This study presents the development of biodegradable adhesion promoters synthesized via the amidation of renewable raw materials (rapeseed oil and higher fatty acids) with polyethylene polyamine. The main objective was to improve bitumen–aggregate adhesion while maintaining the essential physico-mechanical and rheological properties of the bitumen. The synthesized bio-based adhesion promoters were incorporated into penetration-grade bitumen at a dosage of 0.4 wt.%. Physico-mechanical testing confirmed that their inclusion does not significantly affect the fundamental properties of the bitumen, while substantially enhancing adhesion to both glass and mineral aggregates. Rheological analysis showed that the rapeseed oil-based adhesion promoter had minimal influence on viscoelastic behavior. In contrast, the fatty acid-based promoter increased the rutting resistance parameter (|G*|/sinδ) and decreased the phase angle (δ), indicating improved resistance to permanent deformation. FTIR spectroscopy further revealed that the fatty acid-based adhesion promoter significantly reduced the formation of carbonyl groups during short-term aging, suggesting a retardation in oxidative aging and potential rejuvenating effects. In conclusion, the proposed bio-based adhesion promoters, derived from renewable sources and fully biodegradable, represent a promising solution for enhancing bitumen performance and supporting the durability and sustainability of asphalt pavements. Full article

During large-scale pavement construction, the preparation of SBS-modified asphalt typically produces large amounts of harmful fumes. The emergence of deodorants can effectively alleviate the problem of smoke emissions during the asphalt manufacturing process. On the basis of ensuring the original road performance, exploring more suitable dosages and types of deodorant is urgently needed. Five commercial deodorants were evaluated using an asphalt smoke collection system, and UV-visible spectrophotometry (UV) was employed to screen the deodorants based on smoke concentration. Gas chromatography–mass spectrometry (GC-MS) was used to quantitatively analyze changes in harmful smoke components before and after adding two deodorants. Subsequently, the mechanisms of action of the two different types of deodorants were analyzed microscopically using fluorescence microscopy. Finally, the performance of bitumen and asphalt mixtures after adding deodorants was evaluated. The results showed that deodorant A (reactive type) and D (adsorption type) exhibited the best smoke suppression effects, with optimal addition rates of 0.6% and 0.5%, respectively. Deodorant A reduced benzene homologues by nearly 50% and esters by approximately 40%, while deodorant D reduced benzene homologues by approximately 70% and esters by approximately 60%, without producing new toxic gases. Both deodorants had a minimal impact on the basic properties of bitumen and the road performance of asphalt mixtures, with all indicators meeting technical specifications. This research provides a theoretical basis for the effective application of deodorants in the future, truly enabling a transition from laboratory research to large-scale engineering applications in the construction of environmentally friendly roads. Full article

The modern road industry requires a more effective solution according to efficiency and minimizing environmental burden. This article discusses the use of recycled materials to modify bitumen binders within the concept of the circular economy. The main aim of this article was to create a new composite based on waste materials, including polymer waste and rubber crumb. The important element is the usage of locally available waste that has not been investigated previously as a material for asphalt modification. The prepared composition was preliminarily assessed according to chemical composition. Next, research dedicated to road application was conducted, including the following: determination of the resistance to hardening, aging under the influence of high temperature and air, as well as oxidation processes, assessment of penetration, and evaluation of the softening point. The conducted studies showed that the new composites with the addition of polymer waste and rubber crumb improve the thermal stability, elasticity, and resistance of bitumen to aging. Optimum concentrations of modifiers were determined that provide an increase in the performance characteristics of bitumen, including a decrease in the brittleness temperature and an increase in the softening temperature. The obtained results demonstrate the potential for the introduction of new composites based on recycled materials in road construction, contributing to increased environmental sustainability and economic efficiency. Full article

This study explores the potential of oil sludge, a hazardous by-product of the oil industry, as a sustainable rejuvenator for restoring the physicochemical and rheological properties of aged bitumen. Aged binder samples were modified with different concentrations of oil sludge (1%, 3%, and 5%) and analyzed using dynamic shear rheometry (DSR), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The incorporation of 5% oil sludge increased penetration from 60 to 71 mm and the softening point from 55 °C to 72 °C, indicating enhanced flexibility. DSR measurements showed a ~10% decrease in complex modulus (G*) and a slight increase in phase angle, confirming partial rheological recovery. FTIR spectra revealed partial restoration of aliphatic and aromatic functional groups, with a decrease in sulfoxide absorption bands, while SEM analysis indicated improved homogeneity and reduced microcracking. TGA confirmed enhanced thermal behavior and a reduction in residual mass. The novelty of this work lies in the first-time application of regionally sourced oil sludge as a rejuvenator, evaluated through a multiscale analytical framework. These findings demonstrate the dual benefits of performance recovery and hazardous waste valorization, contributing to sustainable road maintenance within a circular economy approach. Full article

The research on nano titanium dioxide (nano-TiO₂)-modified asphalt has received increasing attention. However, further studies are required in order to ascertain the influence of the phenomenon under discussion on the rheological characteristics and ability to resist deformation of bitumen. In the present study, modified bitumen was formulated by adding nano titanium dioxide. Physical property tests, temperature scanning tests, frequency scanning tests, repeated creep recovery tests, bending creep stiffness tests, and long-term aging performance experiments were carried out on the specimen of asphalt that had undergone the process of modification in order to assess the rheological characteristics and ability to resist unrecoverable deformation of the modified bitumen at different temperatures, both high and low. The outcomes of the repeated creep recovery experiment were analyzed using Burgers and fractional derivative models. The microstructure of nano-TiO₂ high-viscosity modified asphalt was observed by Scanning Electron Microscope(SEM). In order to ascertain the manner in which base bitumen and nano-TiO₂ interact, Fourier transform infrared spectroscopy (FTIR) was utilized in the study. The results show that the thermal stability and prolonged aging resistant properties of the modified bitumen binder improved, but nano-TiO₂ made the asphalt binder weaker and more likely to crack at lower temperatures. Taking into account the variation in the road performance of the bitumen binder, 6% is recommended as the optimal amount of nano-TiO₂. Nano-TiO₂ was mainly uniformly distributed in asphalt and nano-TiO₂ was physically mixed with asphalt. In comparison with the Burgers model, the present fractional derivative empirical creep model can fit the creep test data of the asphalt binder well with the advantages of high accuracy and few parameters. The research results provide a reference for promoting the implementation of modified bitumen incorporating nano-TiO₂. Full article

Using a relatively inexpensive method, phenol–cresol–formaldehyde resin (PhCR-F) was produced utilizing the byproducts of coal coking. It is shown that petroleum road bitumens, to which 1.0 wt.% PhCR-F is added, in terms of basic physical and mechanical parameters, comply with the requirements of the regulatory document for bitumens modified with adhesive additives. Research on the operational properties of these modified bitumens as a binding material for asphalt concrete is described. It has been proven that modified bitumen can store stable properties during its application (resistance to aging). The interaction of bitumens modified by PhCR-F with the surfaces of mineral materials, which occurs during the creation of asphalt concrete coatings, was studied. It was shown that adding 1.0 wt.% PhCR-F to road bitumen significantly improves the adhesion of the binder to the mineral material and increases the hydrophobicity of such a coating. The production of effective bitumen modifiers from non-target coking products of coal will not only make it possible to use new resources in road construction but will also increase the depth of decarbonization of the coking industry. Full article

The article reports on the development of a fundamentally new, effective technology for recycling waste tires using the explosive-circulation technology method, which was implemented in industry at a working factory. The construction of an explosion-circulation reactor, in which tires are destroyed under the influence of an explosion, is described. The main technological stages of the reactor operation include the formation of a tire package with a height of about 2.4 m and a mass of up to 1000 kg; cooling the package by air turbo-cooling machine to a temperature of minus 70–80 °C; placing the package into the reactor; initiating the explosive charge; and removing the tire shedding products with a subsequent granulometric classification of the resulting rubber crumb. The resulting rubber crumb has good wettability, which eliminates the need for an additional technological stage of activating the crumb surface. This made it possible to successfully use the obtained rubber crumb to improve the characteristics of road construction bitumen, the hardness of which at −16 °C decreased from 217 to 161 MPa. Using atomic force microscopy (AFM), gas chromatography, mass spectrometry, GPC, and XPS, it was established that the good wettability of the crumbs is explained by the formation of molecules with polar groups (C-O, C=O, C(O)O, C-S, C-SO_x, Zn-S, O-Si(O)-O) on the crumb surface as a result of the explosion. Full article

This study evaluated the environmental sustainability of partially replacing natural aggregates with electric arc furnace (EAF) slag in concrete and porous asphalt mixtures. Both the Equilibrium Leaching Test (EN 12457-4) and the Dynamic Surface Leaching Test (DSLT, CEN/TS 16637-2) were applied to analyse the leaching behaviour of the asphalt mixtures. The results showed that the incorporation of EAF slag led to the release of chromium (Cr), molybdenum (Mo), and vanadium (V), while the type of bitumen affected the dissolved organic carbon (DOC) release. However, when compared to EAF slag leaching, asphalt mixtures exhibited significantly reduced leaching, particularly Cr (by 70%) and V (by 60%). These results indicate that metal leaching follows a diffusion-controlled release mechanism, showing higher concentrations for the porous asphalt compared to the asphalt concrete. The cumulative leaching values at 64 days reached 2.54 mg·m⁻² for Cr, 3.29 mg·m⁻² for Mo, and 28.67 mg·m⁻² for V, far from the limits set by the Dutch Soil Quality Decree (SQD) of 120, 144, and 320 mg·m⁻², respectively. Therefore, this study demonstrated that EAF slag is a viable alternative for sustainable road construction, reducing natural resource consumption and promoting the circular economy. Full article