Search

With the increase in traffic load, the rutting problem of bitumen pavement appears more and more frequently, and the shear resistance of pavement has attracted more and more attention. A polymer-modified bituminous mixture is usually used to solve the problem of insufficient shear resistance in bitumen pavement. However, there are many polymer modifiers for bituminous mixture, which lead to different performances of the modified bituminous mixtures. Currently, the modification methods cannot obtain a bituminous mixture having all types of performance simultaneously. Therefore, considering the different performances and economics of modified bituminous mixtures, it is necessary to determine an optimal modification method for bitumen pavement. This study used a toll plaza in Jilin province, which is a seasonally frozen region. On this section of road, vehicles start and brake at high frequency, and the bitumen middle course suffers from large shearing forces. Therefore, permanent deformation is the main form of failure. In addition, low-temperature cracking of the bitumen pavement is also a very severe issue in this region. Four kinds of bituminous mixture modification schemes were selected and tested, and the pavement performance of these modified bituminous mixtures was evaluated. The fuzzy comprehensive evaluation method was used to quantitatively evaluate the performance level of bituminous mixtures according to fuzzy logic theory. Using the actual situation of the bituminous mixture used in the toll plaza, and based on the analytic hierarchy process method, the weight matrix of each service attribute was established. Here, the weight of each index was calculated by combining the entropy weight (EW) method, reducing the influence of subjective factors. According to the evaluation result of the fuzzy comprehensive evaluation model, it could be seen that the modified bituminous mixture (70#+M) had the best overall performance compared to the other bituminous mixtures. [ABSTRACT FROM AUTHOR]

Graphene can significantly improve the mechanical performance and durability of a bitumen composite. However, the underlying reinforcement mechanism of this enhancement is not yet clear. Here, we use molecular dynamics (MD) simulation to study the mechanisms of tensile fracture and shear fracture in a graphene-reinforced bitumen composite. Two representative volume elements were developed from a single-crystal graphene-reinforced bitumen composite: graphene in the parallel plane and orthogonal plane. The MD results show that graphene in the orthogonal plane is better able to support and transmit shear loads, as evidenced by a 33% higher shear strength than graphene in the parallel plane. Under tensile loading, the failure type of the base bitumen and the graphene in the parallel plane is cohesive; for the graphene in the orthogonal plane, the failure type is adhesive. The shear failure for graphene in the parallel plane is an adhesive failure, which typically occurs at the graphene–bitumen interface. The shear failure for graphene in the orthogonal plane and for base bitumen is likely to be a cohesive failure. The results of the pull-off test validated the results of the simulation, which indicated that the interlayer sliding of graphene and the fracture of the bitumen matrix are the failure modes of a graphene-reinforced bitumen composite under tensile loading. This study provides atomic-level insight into the mechanical reinforcement mechanism of graphene-reinforced bitumen, and can contribute to the future application of advanced carbon nanomaterials in transportation infrastructure. [ABSTRACT FROM AUTHOR]

Littering waste is among the top environmental issues in the world, and the management of the waste has turned into a challenge in almost every city. It has been reported that 75% of smokers dispose of their cigarette butts (CBs) on the ground, even in public places. Researchers have discovered that CBs make up more than one-third of the total littered waste on the planet. Cigarette butts predominantly consist of a cellulose acetate fiber (plastic)-based filter wrapped in paper. Waste CBs contain burnt tobacco and tar, along with many other toxic chemicals. They take years to biodegrade depending on the environmental conditions, and toxic chemicals leach out and contaminate the environment. As part of an ongoing project, this paper presents a novel and sustainable technique to recycle cigarette butts in bitumen for the construction of flexible pavements. In this research, CBs have been pre-processed and mixed with bitumen classes C320, C170, and PMB A10E as a fiber modifier. Comprehensive laboratory investigations, including a penetration test, softening point test, and viscosity test, have been performed along with a binder drain off test to evaluate the performance of the modified samples. During this investigation, samples were prepared with 0.3% cellulose fiber, 0.2%, 0.3% 0.4%, and 0.5% CBs. The results of the CB-modified samples were compared with the sample with cellulose fiber and fresh bitumen (0% fiber). The results show that the physical and rheological properties of bitumen incorporating CBs improve significantly, and CBs could be used instead of virgin cellulose fiber as a fiber modifier.

Over the last years, the replacement of traditional polymer modifiers with waste plastics has attracted increasing interest. The implementation of such technology would allow a drastic reduction of both production cost and landfill disposal of wastes. Among all, polyethylene-based plastics have been proved suitable for this purpose. The research activities presented in this paper aim to assess the synergistic effect of polyethylene and Fischer–Tropsch waxes on the viscoelastic properties and performance of the bitumen. In order to reduce the blending time, waxes, and polyethylene need to be added simultaneously. In fact, the presence of the waxes reduces the polarity of the bitumen matrix and increases the affinity with the polymer promoting its dispersion. Results demonstrate that the chain length of the waxes, the form of the added waste polyethylene, and the blending protocol have critical effects on the time-evolution of such properties. Short-chain waxes have a detrimental impact on the rutting resistance regardless of the blending protocol. On the contrary, long-chain waxes improve the overall behavior of the polyethylene-modified binders and, in particular, the resistance to permanent deformations. [ABSTRACT FROM AUTHOR]

Although archaeological excavations have recovered a large number of vessels used to hold perfumes or ointments in ancient Rome, little is known about the chemical composition or origin of the substances they contained. Most available information pertains to ointment and/or cosmetic bases rather than to essences. The discovery in 2019 of an ointment jar (unguentarium) made of rock crystal (quartz) that was sealed with a stopper and contained a solid mass in a Roman tomb in Carmona (Seville, Spain) was a rather unusual finding. This paper reports the results of an archaeometric study of the unguentarium stopper and its contents. Based on them, and on comparisons with commercially available patchouli and nard oil standards, the perfume held in the unguentarium was probably patchouli. To our knowledge, this may be the first time a perfume from Roman times has been identified, which is a major advance in this field. The unguentarium stopper consisted of dolomite, a material also unknown in this type of use, and bitumen was used to seal the unguentarium with the stopper.

Plastics are not inherently bad, as it is what we do and what we do not do after use that really counts. Plastics are pleasant to the eye, light in weight, sleek to the touch, currently indispensable, relatively cheap and sustainable with good use. Because of these desirable properties, the use, demand and production of plastic goods for various applications are on a steady rise. Consequently, the volume of the corresponding waste is also on the rise due to the non-biodegradable nature of these petroleum-based plastics. Mechanical recycling, which is the widely employed recycling route, is not holistic because it only delays the time for the waste plastics to get to the dump site and litter the environment. The use of waste plastics in bituminous mixtures for road construction is an emerging sustainable route for most types of commodity plastic wastes. This paper reviews the progress, techniques, suitability and possible health and environmental risks of waste plastics for a flexible pavement system. SWOT analysis to highlight the advantages and disadvantages of plastic waste utilization in bituminous mix was also conducted and is reported here.

The contribution of Spanish scientists to the rheology involved in polymer processing during the last 25 years is investigated. It is shown that the performed research covers, at different levels, all industrial polymeric materials: thermoplastics, thermosets, adhesives, biopolymers, composites and nanocomposites, and polymer modified bitumen. Therefore, the rheological behaviour of these materials in processing methods such as extrusion, injection moulding, additive manufacturing, and others is discussed, based on the literature results. A detailed view of the most outstanding achievements, based on the rheological criteria of the authors, is offered. [ABSTRACT FROM AUTHOR]

During the last decades, extensive research has been carried out on using reclaimed asphalt pavement (RAP) material in the production of hot recycled mix asphalt. Unfortunately, the aged, stiff, and brittle binder in the RAP typically increases the mixture stiffness and can therefore cause fatigue and low-temperature damages. In the scientific literature, there are many studies concerning the aging and rejuvenation of bitumen, but there is a lack of up-to-date reviews that bring them together, especially those facing the phenomena from a chemical point of view. In this paper, a recap of the chemical aspects of virgin, aged, and rejuvenated bitumen is proposed in order to provide a useful summary of the state of the art, with the aim of both encouraging the use of an increasing quantity of RAP in hot mix asphalt and trying to give indications for further research. [ABSTRACT FROM AUTHOR]

The paper presents the results of laboratory investigation on asphalt binders relaxation at low temperature, carried out in a ductilometer using the tensile test with continuous force measurement. Polymer modified asphalt binder samples consisting of a 50/70 penetration grade bitumen mixed with a concentrate of styrene-butadiene-styrene (SBS) modified bitumen—a 160/220 penetration grade bitumen modified with a SBS copolymer in the amount of 9%—were tested. Therefore, polymer modified binders containing 3%, 4.5%, 6% and 7.5% SBS, respectively, were obtained and investigated. Tensile tests were performed at −16 °C on samples before aging and subjected to short-term aging (RTFOT). Test results in the form of relaxation curves have been mathematically described using a modified generalized Maxwell model. Based on the acquired results, it was shown that the increase of the SBS copolymer content in asphalt binder precipitates the relaxation process, while aging slows down this phenomenon. It has also been proven that with increased content of SBS elastomer in asphalt binder, the effect of short-term aging on binder's stress relaxation ability at low temperatures is reduced. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the results of two different studies investigating the acute and chronic toxicity of two blends of diluted bitumens ("dilbit") and weathered dilbit on freshwater fish and invertebrates after exposure to different concentrations of physically-dispersed (water accommodated fraction; WAF) and chemically-dispersed (chemically-enhanced WAF; CEWAF). The first study evaluated the acute and chronic toxicity of weathered, unweathered and dispersed Access Western Blend (AWB) dilbit on Fathead minnow (Pimephales promelas). In the second study, acute and chronic toxicity of weathered and unweathered Cold Lake Blend (CLB) dilbit was assessed on Rainbow trout (Oncorhynchus mykiss), and two invertebrate species, Daphnia (Daphnia magna) and Ceriodaphnia (Ceriodaphnia dubia). For Fathead minnow, unweathered AWB WAF demonstrated a significantly higher acute toxicity (LC50–96 h = 0.628 g/L) compared to the weathered AWB WAF (LC50–96 h = 2.06 g/L). Chronic toxicity tests showed that Fathead minnow lethality was also higher for unweathered AWB (LC50-7 d = 0.593 g/L) compared to the weathered AWB (LC50-7 d = 1.31 g/L) whereas larval growth toxicity was lower for unweathered AWB (IC25-7 d=0.312 g/L) compared to the weathered dilbit (IC25-7 d = 0.096 g/L). Rainbow trout exposed to unweathered CLB demonstrated a significantly higher toxicity (LC50–96 h = 5.66 g/L) compared to the weathered CLB (LC50 > 18 g/L). Lethality (LC50 = 6.43 g/L) was observed in Ceriodaphnia exposed to the CLB WAF while no mortality was observed with the weathered CLB. The reproductive effects on Ceriodaphnia were greater with the CLB (IC25 <1.0) than with the weathered CLB (IC25 = 3.99 g/L). Volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH) and total petroleum hydrocarbons (TPH) increased as the dilbit CLB and AWB WAF concentrations increased. The total VOC and the total PAHs (including the alkylated PAHs) presented similar concentrations in the weathered and unweathered AWB WAF. These compounds seem therefore not be affected by the AWB WAF weathering process. However, VOC and PAH concentrations decreased significantly in the Rainbow trout and Ceriodaphnia toxicity tests using the weathered CLB WAF. VOC and PAH concentrations were also lower in the weathered AWB CEWAF used for Fathead minnow chronic study. [ABSTRACT FROM AUTHOR]

Starting from the eighties, the use of nanoadditives registered an increasing attention in the scientific and patent literature, especially for the case of polymeric nanocomposites. In the last decade, this involved bituminous materials, modified either with nanosized fillers or with polymeric nanocomposites. One of the expected benefits is an increased resistance of the binder to aging. After a short introduction underlining the uncertainties and risks of artefacts in aging tests, a review is given, focusing on the antiaging properties of layered silicates, which are by far the most important nanoadditives for bitumens. Together with layered silicates, other materials such as nanohydrated lime, nanosilica, and layered double hydroxides are mentioned. Preparation and characterization of the binary bitumen/layered silicate and ternary bitumen/layered silicate/polymer systems are described in order to individuate the aspects that influence the antiaging effect. Even if the available literature is quite abundant and unanimously confirms that nanoadditives may improve bitumen durability, there is a lack of studies clarifying the involved mechanisms. As it is for conventional fillers, it seems to be a combination of physical and chemical interactions. Nanoadditives with different chemistries, porosities, and interlayer spacings differently absorb the polar components from the bitumen, thus affecting their predisposition to oxidative aging. [ABSTRACT FROM AUTHOR]

Highlights • Proposed a multistage stochastic programming model for bitumen upgrading plant capacity expansion planning. • Solved the stochastic programming problem through linear decision rule based method. • Addressed synthetic crude oil price uncertainty through time series model and constructed uncertainty set. • Results show that the effect of CO 2 tax rate uncertainty on the expansion planning is not significant. Abstract Expansion development of upgrading plants is an important decision to make for the oil sands industry. In this paper, we propose a multistage stochastic expansion development method to tackle uncertain synthetic crude oil (SCO) and CO 2 tax prices. The linear decision rule based technique is applied to solve the proposed stochastic optimization model. Various analyses are conducted based on optimization results: (i) effects of the uncertainty set size, (ii) comparison of solutions for selected pessimistic, realistic, and optimistic scenarios, (iii) effects of different operating modes for an upgrading plant, and (iv) cost distribution. Results of this work demonstrate that the stochastic model provides a more flexible, economical, and robust solution compared to the deterministic solution. In addition, the CO 2 tax price affects the optimal solution negligibly compared to the SCO price. Finally, expansion development of the studied upgrading plant is economically beneficial even at the current market state. [ABSTRACT FROM AUTHOR]

The growing needs for sustainability demand that porous asphalt (PA), one of the most critical types of asphalt mixtures, can be produced with high quality, low production temperature and using high percentages of reclaimed materials. With the support of the European Life+ program, a new decomposition technique was developed to decompose the reclaimed PA into the mortar sand (grain size ≤ 2 mm, bitumen content 10–14%) and the reclaimed stones in various fractions (bitumen content less than 1%). The reclaimed mortar sand can then be rejuvenated, enriched and homogenized to obtain a high quality mortar. When this mortar is mixed with the reclaimed stones, a high quality PA can be obtained with almost 95% reclaimed materials. This paper discusses the influence of different production techniques on the performances of this mixture. These techniques include (A) conventional hot production technique at 170 °C, (B) the cold feed of reclaimed mortar sand in combination with bitumen foaming obtaining a mix at 105 °C and (C) the hot production of mortar in combination with the newly developed mortar foaming method to obtain a mixture at 105 °C. Laboratory results indicate that the PA may be produced at 105 °C, containing up to 93% reclaimed materials and having a high quality. [ABSTRACT FROM AUTHOR]

Currently, Steam-Assisted Gravity Drainage (SAGD) is the most successful commercialized method used to produce bitumen from oil sands and heavy oil reservoirs. Precise description of the steam chamber evolution is important for evaluating the economic effectiveness and Greenhouse Gas (GHG) emission of the SAGD process. In this study, the properties of MacKay River Oil Sands were used in laboratory experiments to compare the chamber evolution and production performance of SAGD under different permeability distributions. Then, a mathematical model was established to predict the steam chamber evolution and the closely related oil production and heat consumption in a heterogeneous formation. Next, the calculated production performance and steam chamber evolution were compared with measured experimental data to verify the accuracy of the model. Finally, the chamber evolution characteristics and their impacts on SAGD oil production and heat consumption are discussed in this paper for formations with different permeability distributions. The results indicate that horizontal permeability controls the evolution of steam chamber such that higher horizontal permeability may cause an obvious convex shape of the chamber edge, whereas vertical permeability has little effect on the chamber shape despite significant influence on the oil production in the early stage of SAGD. Moreover, a convex-shaped chamber interface indicates a higher production rate in the spreading stage and a lower rate in the depleting stage. In addition, this study shows that to minimize the heat consumption of the SAGD process, so that GHG emission can be curbed, a concave-like chamber shape is favorable in the early spreading stage, whereas a convex shape is better in the late spreading stage and depleting stage. [ABSTRACT FROM AUTHOR]

The paper reports the results from the tests of recycled mixture samples containing waste materials. Six types of waste materials were used in the mineral mix, in various configurations. Statistical inference was based on the multidimensional analysis through the reduction of input data size. Three groups of recycled mixtures were identified, each representing significantly different properties. The first group included rigid recycled mixtures, the second group comprised flexible mixtures, and those with the lowest cohesion and rigidity were in the third group. The statistical inference demonstrated that the recycled mixtures with waste materials to be most recommended were those with a high bitumen content (>2.5%). A high proportion of reclaimed asphalt pavement material was found to provide high performance of the recycled mixture, whereas recycled aggregate reduced the stiffness of the mix and its resistance to moisture. [ABSTRACT FROM AUTHOR]

Utilization of cavitation in advanced oxidation processes (AOPs) is a promising trend in research on treatment of industrial effluents. The paper presents the results of investigations on the use of hydrodynamic cavitation aided by additional oxidation processes (O 3 /H 2 O 2 /Peroxone) to reduce the total pollution load in the effluent from the production of bitumens. A detailed analysis of changes in content of volatile organic compounds (VOCs) for all processes studied was also performed. The studies revealed that the most effective treatment process involves hydrodynamic cavitation aided by ozonation (40% COD reduction and 50% BOD reduction). The other processes investigated (hydrodynamic cavitation + H 2 O 2 , hydrodynamic cavitation + Peroxone and hydrodynamic cavitation alone) ensure reduction of COD by 20, 25 and 13% and reduction of BOD by 49, 32 and 18%, respectively. The results of this research revealed that most of the VOCs studied are effectively degraded. The formation of byproducts is one of the aspects that must be considered in evaluation of the AOPs studied. This work confirmed that furfural is one of the byproducts whose concentration increased during treatment by hydrodynamic cavitation alone as well as hydrodynamic cavitation aided by H 2 O 2 as an external oxidant and it should be controlled during treatment processes. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oil shale is an unconventional energy resource with high nitrogen content. In this study, XPS, GC–MS and ESI FT-ICR MS were carried out to investigate the nitrogen compound migration during pyrolysis, with thermal bitumen as the intermediate. The results showed that the yield of thermal bitumen was highest when the reaction temperature was 380 °C. In the process of pyrolysis, amines and some nitrides generate ammonia gas due to the hydrogen transfer process, or they generate low-grade amines, which subsequently dissolve in pyrolysis water due to bond breakage during the pyrolysis process. As determined by GC–MS analyses, the basic components in shale oil are mainly quinoline compounds. Benzocarbazole and dibenzocarbazole compounds, such as C1-benzocarbazoles, C2-benzocarbazoles and C3-benzocarbazoles, were detected via ESI FT-ICR MS in thermal bitumen. [ABSTRACT FROM AUTHOR]

Aging due to sunlight and the passage of time is an effective element in the occurrence of moisture damage in hot asphalt mixtures. Still, the effects of this parameter are scarcely considered in the experiments examining the moisture damage potential. Accordingly, this study investigated the effect of aging on the performance of hot asphalt mixtures and examined the improvement of moisture damage performance by using antistripping additives via mechanism and functional tests. Two types of aggregates (limestone and granite) with different degrees of moisture sensitivity, two types of bitumen (PG64-16 and PG58-22) with different performances, and two additives (Wetfix liquid additive and nanohydrated lime) as bitumen modifiers were used. Bitumen samples and asphalt mixtures were subjected to short- and long-term aging. The pull-off test was performed to explore the aging effect on different failure mechanisms (cohesion and adhesion), and the indirect tensile stiffness modulus (ITSM) test was conducted to study the asphalt mixture's performance against moisture damage. The results specify that aging, in terms of hot asphalt mixture hardening in dry and wet conditions, decreased the MSR (resilient modulus wet to resilient modulus dry ratio), and this decline was greater in long-term aging. The pull-off test results exhibited that aging, especially in the long term, decreased the asphalt mixture's adhesive strength in dry and wet conditions; this decline in adhesion was greater in the wet than in the dry state, and this difference decreased the wet-to-dry adhesion strength ratio (the pull-off ratio). The additives relatively improved the yield modulus of the asphalt mixture, but their effect was greater in the wet state. A comparison of the pull-off test results in cohesion and adhesion failure demonstrated that Wetfix was more effective in improving bitumen–aggregate adhesion, whereas nanohydrated lime was more effective in enhancing bitumen adhesion. The resilient modulus (Mr) ratio in wet-to-dry conditions indicated that nanohydrated lime had better effects on the overall performance of the aged asphalt mixture against moisture damage. To investigate the effect of additives on the performance of asphalt mixtures, a t-test was performed in all modes of control, short-term aging, and long-term aging. The findings showed the effect of Wetfix and nanohydrated lime on increasing the modulus of elasticity of the samples. [ABSTRACT FROM AUTHOR]

The preparation and application of microcapsules containing healing agents have become a crucial way to enhance the self-healing capability of bitumen. This intelligent material has become a hot topic in the field of pavement material and has greatly stimulated the development and applications of pavement engineering. However, there has been no research focused on the relationship of the multistructures from the viewpoint of molecular-size, microsize, and macrosize, which significantly limits the predictions of the self-healing efficiency and structure design of this self-healing material. The purpose of this study was to make a mathematical analysis of the influencing factors of self-healing efficiency based on the self-healing mechanism of bitumen using microcapsules, fully considering the structural dimensions, preparation conditions, and self-healing conditions. In the mathematical analysis, the cross-linking degree of the shell material molecules of the microcapsules was considered for its damage strength from the perspective of molecular structure. The final tip stress of the microcrack was believed to be equal to the puncture strength of the microcapsules in terms of microsize. From a macroscale point of view, the amount of healing agent released from the microcapsule rupture was considered more significant than or equal to the volume of the microcracks. At the same time, the time–temperature superposition principle was applied to simplify the influence factors. The above derivation based on multiscale structures found that the additive amount of the microcapsules, temperature, and time were the three main influencing factors on the self-healing features of bitumen. Finally, the experimental data was investigated considering the three factors, which thoroughly verified the feasibility of the derivation. All results will help to establish a bridge between the initial structural design of self-healing bitumen and the prediction of the final self-healing effects. [ABSTRACT FROM AUTHOR]

This research study aims to investigate the feasibility of incorporating high-density polyethylene waste (HDPEW) into bitumen applications. Two conventional conditions of bitumen, namely, aged bitumen (AB) and virgin bitumen (VB), are rejuvenated and modified, respectively, using post-consumer HDPEW sourced out of bottle crates. The outcome (Pyro oil, PO-HDPEW) of the pyrolysis thermochemical process is used by 10, 20, and 30% to rejuvenate AB, while the fine-ground granules (FG) (FG-HDPEW) are used by 2, 3, 4, and 5% to modify the VB with different percentages. Physical and rheological characterization testing, including penetration, softening point temperature, and rotational viscosity (RV), is conducted to evaluate the performance of the HDPEW-rejuvenated and -modified binders and optimize both rejuvenator and modifier percentages. In addition, physical and chemical tests, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) are conducted to analyze the composition, distribution of surface contaminants, and the molecular structure of the bitumen, based on their respective wavelengths. Moreover, advanced mechanical and rheological tests, including dynamic shear rheometer (DSR), multiple stress creep and recovery (MSCR), and linear amplitude sweep (LAS) tests, are conducted to investigate the susceptibility of the rejuvenated and modified bitumen with HDPEW to rutting and fatigue cracking. The testing results demonstrate that the addition of PO-HDPEW to AB and FG-HDPEW modification of VB can enhance the physical, chemical, mechanical, and rheological properties of bitumen; however, this study recommends further research on the aging performance of the PO-HDPEW-rejuvenated bitumen. This research provides insights into using HDPEW as a cost-effective and eco-friendly rejuvenator and modifier on bitumen properties, which can aid in the longevity and performance of pavements. [ABSTRACT FROM AUTHOR]

Copyright of Military Technical Courier / Vojnotehnicki Glasnik is the property of Military Technical Courier / Vojnotehnicki Glasnik and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Environmental approaches in the asphalt industry have focused on utilizing waste materials as modifiers. Lignin is a high-potential bitumen modifier due to its characteristics; however, the blending process with bitumen is critical. This study investigates the chemo-thermal characteristics of lignin-modified bitumen under two different blending protocols, including a mechanical and high-shear mixer to evaluate its performance as a modifier. According to the protocols, 5, 10, and 20% of Kraft lignin was added to a PG 58S−28 bitumen. The samples were subjected to analysis using Brookfield Rotational Viscosity (BRV), Dynamic Shear Rheometer (DSR), Fourier-Transform Infrared Spectroscopy (FTIR), Environmental Scanning Electron Microscopy (ESEM), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC) tests. The BRV and DSR test results indicate a remarkable alteration in the rheological properties of lignin-modified bitumen under blending conditions. The FTIR analysis indicated that Kraft lignin did not produce new functional groups. The fibril structures of the bitumens are affected by Kraft lignin content and blending conditions due to ESEM. The Kraft lignin and blending conditions influence the thermal behavior of bitumen. The findings highlight Kraft lignin's potential as a bitumen modifier, and the fact that its characteristics are influenced by the blending protocol and Kraft lignin content. [ABSTRACT FROM AUTHOR]

In order to study the slope stability of an impervious layer asphalt concrete panel, in this study, the maximum aggregate size used was 19 mm, and a slope flow value test was carried out after changing the gradation index, filler content and bitumen aggregate ratio. The test results showed that the relationship curve between the slope flow value and the test time was mainly divided into three stages for the slope flow value: an almost linear growth stage, a gradual stabilization stage, and a stable stage. The grading index, bitumen aggregate ratio and filler content had an effect on the slope flow value of asphalt concrete. The slope flow value decreased with the increase in the grading index. A reasonable increase in the grading index can increase the slope stability of the asphalt concrete panel. The slope flow value increased with the increase in the filler content and bitumen aggregate ratio. When the filler content exceeded 13%, the slope flow value significantly increased. At the same time, it was also verified that the asphalt concrete slope with the maximum aggregate size of 19 mm had good thermal stability. On this basis, a prediction model of asphalt concrete slope flow value and test time was established. The model considered the effect of different parameters of mix proportion on the slope flow value. The calculation results were in good agreement with the test results. [ABSTRACT FROM AUTHOR]

Polyphosphoric acid (PPA) and styrene–butadiene–styrene (SBS) were adopted to produce PPA-SBS-modified bio-blend bitumen, which achieved excellent mechanical performance. However, its long-range performance, such as the fatigue and thermal cracking behavior under long-term thermal oxidation, is not well understood. Therefore, a pressure aging vessel (PAV) system was applied to simulate the aging behavior of the bitumen under the action of thermal oxidation. Then, a linear amplitude sweep (LAS) test combined with a viscoelastic continuum damage (VECD) model was applied to investigate the fatigue properties of the bitumen. Moreover, a bending beam rheometer (BBR) test was conducted to evaluate the thermal cracking resistance of the bitumen before and after PAV aging. Meanwhile, an atomic force microscope (AFM) was applied to observe the microscopic topography. The results show that the original compound-modified bitumen can bear more fatigue damage than that of the control bitumen at the failure point, and it also has excellent fatigue resistance at 2.5%, 5%, 7.5%, and 10% applied strain. Moreover, the VECD model can accurately predict the fatigue life of the bitumen under different applied strains. The variation ratio of stiffness modulus for the compound-modified bitumen is below that of the control bitumen after PAV aging, so it shows a better anti-aging performance. Finally, the AFM test shows that PPA and bio-bitumen decrease the heterogeneity of the bitumen, reducing the difference between phases. [ABSTRACT FROM AUTHOR]

The oily rejuvenator acted as the healing agent in microvasculars. A tensile test was designed to evaluate the self-healing efficiency of asphalt affected by microvascular number, self-healing time and temperature. It was found that the healing agent was slowly released through the microporous channels on the inner shell of the microvascular. The release modes of the agent can work together to improve the self-healing efficiency. The self-healing values of the three samples (asphalt, asphalt/microvasculars without rejuvenator and asphalt/microvasculars with rejuvenator) are 51%, 53%, and 71%. The self-healing capability of the asphalt samples with a healing agent is much greater than that of the other two without a healing agent at the same time. More microvascular rupture at the asphalt sample interface led to a higher self-healing efficiency. The self-healing efficiency values of the three samples (asphalt samples with one, two, and three microvasculars) are 52%, 67%, and 73%, respectively. The self-healing efficiency of the same sample increased during 1–3 days from 26% to 88% in one self-healing cycle. The self-healing efficiency value indicated that increasing the temperature improved each sample's self-healing efficiency. The above trend of change also applies to the second self-healing process. A higher temperature reduces the resistance to molecular motion and accelerates the molecular action of bitumen and the healing agent. The time–temperature equivalence principle can be fully applied to comprehend asphalt self-healing. [ABSTRACT FROM AUTHOR]

This study aims to enhance the performance of the microsurfacing mixture and evaluate the parameters affecting this mixture. For these purposes, the effects of pure bitumen types for producing bitumen emulsion, types of aggregates, and the percentages of bitumen emulsion and emulsifier on the microsurfacing mixture are investigated. Three different types of pure bitumen with penetration grades of 40–50, 60–70, and 85–100 were used to make bitumen emulsion. In addition, limestone and siliceous aggregates, 0.9%, 1.2%, 1.5% emulsifier, and 9%, 10%, and 11% bitumen emulsion were used for test samples. The microsurfacing mixture was then evaluated by cohesion, wet track abrasion, loaded wheel, and mixing time tests. The results revealed that increasing the percentages of bitumen emulsion, emulsifier, limestone aggregates, and bitumen emulsion made from softer pure bitumen increased the microsurfacing mixture's breaking time. Moreover, the test sample containing bitumen emulsion made from harder pure bitumen, limestone aggregates, and lower emulsifier percentages showed a better setting time, which is suitable for a quick traffic reopening system. In addition, using limestone aggregates, pure bitumen with a lower penetration grade and a higher emulsifier percentage declined the optimum bitumen emulsion percentage. It also enhanced the microsurfacing mixture's resistance to abrasion, rutting, and moisture sensitivity. Overall, using limestone aggregates and bitumen emulsion made from harder pure bitumen improved the microsurfacing mixture performance, preventing some distresses, including rutting, stripping, bleeding, and aggregates' polishing, which can lead to the longer service life of this mixture. [ABSTRACT FROM AUTHOR]

In this research, the properties of two tailings solvent recovery unit (TSRU) samples, one bitumen froth sample and two aggregates, are evaluated using various laboratory tests. The TSRU-modified mixtures are prepared at different concentrations of bitumen froth (0%–6% of weight of mixture increasing in 1% intervals) where TSRU materials were added based on optimum moisture content of the mixture. The properties of the mixtures are investigated using indirect tensile strength and Marshall stability tests. The results show that TSRU modification results in a higher tensile strength. The granular layer thickness can be reduced by 42% and 60% for modified samples made with both aggregates. It should be noted that the modified samples fail to meet the soaked indirect tensile strength requirement. A potential solution to improve the indirect tensile strength of the soaked mixture is using cementitious additives such as Portland cement. [ABSTRACT FROM AUTHOR]

The production and maintenance of road pavements consume resources and produce wastes that are disposed of in landfills. To make more sustainable this activity, we have envisioned a method based on a circular use of residues (oil and char) from municipal solid waste pyrolysis as useful additives for producing improved asphalts and for recycling old asphalts to generate new ones, reducing at the same time the consumption of resources for the production of new road pavements and the disposal of wastes to landfills. This work aims to show the feasibility of the integration of two processes (thermal treatment of municipal solid waste on one side, and that of road pavement production on the other side) where the products deriving from waste pyrolysis become added-value materials to improve the quality of road pavements. In this contribution, we presented the effect of pyrolysis product addition on asphalt binder (bitumen) preparation and aging. Solid and liquid products, deriving from the pyrolysis of two kinds of wastes (refused derived fuel (RDF) and granulated rubber tyre waste), have been used for the preparation of asphalt binder samples. Rheological tests have been performed to determine the mechanical properties of neat asphalt binder (bitumen) and those enriched with pyrolysis derived products. Measurements to evaluate possible anti-aging effects have been also performed. The collected results indicate that char addition strengthens the overall bitumen intermolecular structure while bio-oil addition exerts a rejuvenating activity. [ABSTRACT FROM AUTHOR]

The disposal of waste accumulation has become a significant challenge in Oman due to the increasing population. Co-biodegradability issues arise from accumulating two types of non-co-biodegradable waste materials: plastic and rubber. Asphalted pavements experience various stresses resulting from high traffic density, leading to numerous problems. This study aims to investigate the impact of incorporating waste plastic and rubber on the engineering properties of bitumen. Specifically, the study examines the addition of waste tyre rubber (4% and 6%) and waste polyethylene terephthalate (PET) (4% and 6%) to bitumen with a grade of 85/100. Three tests were conducted to evaluate the physical properties of the bitumen, including softening points, penetration tests, and viscosity tests. The results demonstrate that the penetration of bitumen with the addition of 6% waste tyre rubber and PET was 9% lower compared to the 4% mixture for both waste materials. Furthermore, tyre rubber-modified bitumen exhibited higher softening points (79 °C, 2580 s) and viscosity when compared to plain bitumen (48 °C, 1800 s) and PET-modified bitumen (53 °C, 2150 s). These differences indicate that incorporating waste PET and tyre rubber improves the engineering properties of bitumen. This study highlights the importance of increasing the softening point of bitumen in Oman's high-temperature areas. [ABSTRACT FROM AUTHOR]

Currently, few studies explore the internal phases of styrene-butadiene-styrene (SBS) modified bitumen at the nanoscale, though the surface phases of SBS modified bitumen have been deeply understood through a lot of research. The present study uses the atomic force microscopy (AFM) peak force quantitative nanomechanical mode (PF-QNM) to investigate the nanomechanical properties of the interior of linear SBS modified bitumen and corresponding mastics at the nanoscale. Firstly, the suitable experimental methods for the interior of bitumen and mastics are explored. Then, the phase relationship between surfaces and interiors of linear SBS modified bitumen is determined by analyzing nanomechanical properties. On this basis, in comparison with the internal phases of base bitumen, the effect of modifiers on phases is deeply investigated. Finally, the internal phases of linear SBS modified bituminous mastics are further investigated. The results reveal that the interior of linear SBS modified bitumen only has two phases, which form in a manner like periphase and paraphase on the surface. In contrast to base bitumen, linear SBS modified bitumen does not create new phases and change the properties of original phases in the interior, but affects the proportion of A-phase and B-phase and presents the homogenization. Furthermore, due to the influence of preparation methods, only the bitumen area away from the fillers can be imaged by AFM PF-QNM. It can be found that the addition of mineral fillers also slightly changes the internal phase distribution of linear SBS modified bitumen, while the effect is less than that of fillers on base bitumen. [ABSTRACT FROM AUTHOR]

Marble dust waste powder generated by the marble cutting industry has a high alkalinity. In this research, the use of marble dust (MD) as a mineral filler substitute in hot mixed asphalt (HMA) was evaluated. The Marshall mix design was used to determine the optimum bitumen content (OBC) for all of the mixtures. For each of the four MD contents, i.e., 0, 2%, 4%, and 6% by weight of the total aggregates, four different bitumen percentages were used. The results of the Marshall stability test showed that the optimum filler content was 4% MD. Samples were prepared with 0 MD in the control mix and varying percentages of MD as an alternate filler. In addition, MD aided in increasing the Marshall stability, rutting resistance, and permanent deformation and reduced the fatigue life of asphalt mixtures. As the percentage of MD increases, the rutting resistance and stiffness at high temperatures both increase. As the percentage of MD increases, the fatigue life reduces. Rut resistance in high-temperature conditions can be improved by using MD in HMA as a partial substitute for stone dust (SD). In areas where extensive MD waste is present, MD can be incorporated into HMA mixtures instead of conventional fillers. [ABSTRACT FROM AUTHOR]

Recently, many studies have been carried out on the use of waste materials in bitumen modification. In this way, environmental and economic benefits are obtained and a field of use is created for waste materials. In this study, magnesium lignosulfonate (MLS), which is an organic waste material released during paper production from wood, was added to B50/70 bitumen. Penetration, softening point, rolling thin film oven test (RTFOT) and rotational viscometer (RV) tests were performed on modified binders. As a result of the experiments, it was determined that MLS increased the consistency, softening point and short-term aging resistance of the asphalt and decreased the temperature sensitivity. In addition, the activation energy values were determined using the Arrhenius equation and the flow properties were evaluated.

The increasing demand for water with the industrialisation of the world is becoming a major problem as there is a water shortage all over the earth. Therefore, the water problem is one of the important problems that needs to be effectively solved. This paper presents the results of research on wastewater treatment of bitumen production in Mangystau region, which after physical and chemical treatment methods are sent to natural evaporation fields. As a result of research work method of wastewater treatment of bitumen plant was developed, which includes two stages: distillation of water on the solar plant and ozonation in order to oxidize volatile organic matter. Distillation to obtain primary treated water of 70-75% volume was carried out at 33-37 ℃ ambient temperature and 15-30kPa rarefaction, at the same time COD of water was reduced by 68%.

The sustainability of resources is presently a major global concern. Sustainable construction materials can be produced by applying biological waste to engineering. Eggshells, as biological waste, are usually dumped in landfills or discarded. This causes many environmental problems including malodor, noise pollution, and serious waste of resources. To solve these problems, this study combined eggshell waste with bitumen materials for bio-roads construction. This paper investigated the impact of biological waste eggshell powder on the high- and low-temperature characteristics of bitumen materials. Scanning electron microscopy (SEM) revealed the microstructure of eggshell powder. The interaction between eggshell powder and asphalt was analyzed using Fourier transform infrared spectroscopy (FT-IR). The high- and low-temperature characteristics were investigated using conventional performance tests, and dynamic shear rheometer (DSR) and bending beam rheometer (BBR) experiments. These results indicate that eggshell powder (1) has a rough and porous microstructure; (2) has no apparent chemical reaction with asphalt; and (3) improves the consistency, hardness, and high-temperature characteristics. However, it reduces the plastic deformation capacity of asphalt, and the low-temperature crack resistance of asphalt cannot be improved. The research demonstrated that the application of eggshell powder in asphalt is feasible and has long-term resource and environmental advantages. [ABSTRACT FROM AUTHOR]

The increasing demand for non-renewable resources such as bitumen is a significant problem in the pavement industry. Flexible pavement primarily relies on and consumes a large quantity of bitumen, which has become a significant problem in terms of environmental sustainability and economic standpoints. Hence, researchers strive to explore alternative solutions such as bitumen modifiers to prolong the lifespan of flexible pavements. One such modifier is natural rubber (NR), and it has exhibited some beneficial effects for bitumen and asphalt mixtures. However, its adoption as a modifier in the pavement industry is constrained. Hence, the main objective of this review is to analyse the literature in depth to reveal the possibilities of alternative uses of NR as a modifier in the pavement industry. NR in the forms of latex and cup lump was observed to improve the physical, rheological, and mechanical performance of bitumen. The uncross-linked polymer of fresh NR can easily swell and be absorbed by bitumen. In addition, the effect of blending variables is interdependent on the physical properties of the modified bitumen. However, NR decreases the workability of the asphalt mixture, which can be compensated for by warm mix additives. The optimum content of NR for bitumen to improve pavement performance is 4–6 wt.%. Meanwhile, NR absorbs 24.9 kg of CO 2 to produce 1 kg of NR latex. This paper also discusses improved field condition indicators of NR-modified pavements. Finally, recommendations for future research and development are provided to promote the utilisation of NR in the forthcoming sustainable pavement industry. • Research papers on bitumen modification with natural rubber were reviewed. • Natural rubber improves the rheological behaviour of bitumen. • Natural rubber improves the mechanical properties of hot mix asphalt. • Cup lump rubber has been identified as promising form for the modification of bitumen. [ABSTRACT FROM AUTHOR]

In recent years, the research on bitumen has reached the nanometer level, but there are still some problems in the study of the relationship between the atomic force microscope (AFM) nano-morphology and ageing of bitumen. The purpose of this paper is to find out the effect of thermal oxygen ageing on the nano-morphology of bitumen. Atomic force microscope (AFM) test sample of bitumen was prepared in this paper. Area ratio of bee-like structure, roughness, and maximum amplitude were selected as the nano-morphological parameters of the bitumen. The calculation method of nano-parameters was also proposed. Bitumen with different ageing degrees was prepared by thin film oven test (TFOT). Nano-morphological parameters of bitumen with different ageing degrees were obtained by AFM and analyzed with NanoScope Analysis, and the relationships between nano-morphological parameters and bitumen technical indexes after ageing, such as penetration, ductility, softening point, and viscosity were analyzed. The test results show that the wave crests and wave troughs of the bee-like structure on the surface of the bitumen alternate, while the other areas are relatively flat. The bee-like structure continues to develop as the ageing time prolongs, and the number of bee-like structures decreases, but the volume and the undulation degree increase. With the ageing time prolonging, the nano-parameters of bitumen, such as the area ratio of bee-like structure, roughness, and maximum amplitude, show a trend of increasing gradually, but the increasing rates become smaller and smaller. During the ageing process of bitumen, with the increase of nano-morphological parameters (area ratio of bee-like structure, roughness, and maximum amplitude), penetration at 25 °C and ductility at 15 °C of the bitumen decrease, and softening point and viscosity at 60 °C increase. AFM testing technology and image analysis method in this paper can be used for a reference in the nano-scale study of bitumen.

As a good asphalt modifier, natural asphalt has been the focus of more attention because of its low price and ability to improve the performance of modified asphalt. In this paper, the incorporation of a natural asphalt binder in the production of bituminous materials for pavement application in China was experimentally investigated to evaluate the feasibility of such a process and its potential benefits in terms of performance. For this purpose, an asphalt binder conventionally used in the south of China was blended with various percentages of a hard natural binder obtained from the region of Selenice in Albania. The content of Selenice natural bitumen (SNB) was 80.5%, having high molecular weight and the advantages of good stability and compatibility with virgin asphalt. The physical, rheological, and mechanical properties, as well as the modification mechanism of the binder and corresponding asphalt mixture, were evaluated in the laboratory. It was observed that the hard binder improved the response of the binder blend at high and intermediate temperature; this reflected a better stability, improved moisture susceptibility, and enhanced rutting resistance of the mixture. Fluorescence microscopy showed that after dissolving, the size of the SNB modifier became smaller and its distribution was uneven, presenting three forms, granular, agglomerated, and flocculent properties. Chemical test results showed that the modification mechanism of SNB was mainly related to the enhancement of hydrogen bonds and Van der Waals forces caused by sulfoxide and carbonyl along with the stress concentration caused by silica particles. Molecular composition revealed that the proportion of middle molecules has reduced while the proportion of large molecules has increased. It is considered that SNB is a promising low-priced natural modifier with excellent rutting resistance properties. Future research will be focused on the economic analysis, pavement life cycle assessment of SNB modified asphalt, and its application in perpetual pavements. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to promote the application of nano-TiO2/CaCO3 in bituminous materials and present an experimental characterization of viscoelastic behaviors of bitumen and bituminous mixture modified by nano-TiO2/CaCO3. In this work, a series of viscoelastic behavior characterization tests were conducted, including dynamic shear rheometer (DSR) test for bitumen, uniaxial static compression creep test and dynamic modulus test for bituminous mixture. Moreover, various viscoelastic models with clear physical meanings were used to evaluate the influence of nano-TiO2/CaCO3 on the macroscopic performance of bitumen and bituminous mixture. The results show that bitumen and its mixtures are time-temperature dependent. The Christensen-Anderson-Marasteanu (CAM) model of frequency sweep based on DSR test indicated that adding nano-TiO2/CaCO3 can effectively capture the sensitivity of temperature. In addition, the incorporation of nano-TiO2/CaCO3 in bituminous mixture can significantly enhance the high-temperature anti-rutting, and slightly improve the low-temperature anti-cracking as well. At the same time, the modified Burgers model can accurately describe the viscoelastic behavior of bituminous mixtures in the first two creep stages, reflecting the consolidation effect of bituminous mixture. Also, the generalized Sigmoidal model can accurately grasp the characteristics of the relationship between dynamic modulus and reduced frequency and achieve good prediction effects in a wider frequency range. [ABSTRACT FROM AUTHOR]

The paper presents the results of tests of the impact of hydraulic and bituminous binders on the properties of the cold-recycled mixture (CRM). The composition of the cold-recycled mixture includes two types of different binders, i.e., bituminous binder in the form of foamed bitumen and bitumen emulsion, as well as Portland cement (CEM I 32.5R) and hydraulic binder. The hydraulic binder was produced by mixing three base ingredients in the following ratio: 40% CEM I 32.5R; 20% Ca(OH)2 and 40% CBD (cement bypass dust). The cold-recycled mixtures were produced under industrial conditions on a test section. The prepared CRM with bitumen emulsion (MCE) and foamed bitumen (MCAS) was collected from the test section and compacted under laboratory conditions. The impact of the type and kind of the binder was assessed in terms of physical properties, mechanical properties and deformation modulus (bearing capacity of subbase) of the recycled base course after 1, 7 and 28 days. It was found that the use of hydraulic binder in the recycled base course, regardless of the type of bituminous binder, reduced cohesion without reducing the remaining parameters. [ABSTRACT FROM AUTHOR]

The benefits of the use of cold recycling mixtures (CRMs) in pavement rehabilitation are associated with both the reduction of natural resource consumption by replacing them with recycled materials and the reduction of energy consumption during their production and paving. The evolution of the stiffness of CRMs in road construction and the fatigue life of pavements with CRM base layers are still being investigated. In this paper, CRMs with 1% cement content, called bitumen-stabilized materials with bitumen emulsion (BSM-Es), were examined. Mixtures that were differentiated in terms of Reclaimed Asphalt Pavement (RAP) content, as well as the amount and type of bitumen emulsions, were subjected to indirect tensile stiffness modulus (ITSM) tests at 5 °C, 13 °C, and 20 °C. The thermal sensitivities of the BSM-E mixtures were analyzed. BSM-E mixture stiffness modulus levels at various temperatures were determined using a statistical approach. On the basis of the results obtained, a discussion on the mechanistic-empirical design of flexible pavements with BSM-E base layers is presented. The potential benefits of using BSM-E materials in road construction in certain aspects of pavement life are indicated. [ABSTRACT FROM AUTHOR]

This study is the first of two companion papers using hyperspectral data to generate predictive models of oil sand ore and froth characteristics as a potential new means for process control. In Alberta, Canada, shallow oil sands deposits are accessed by surface mining and crushed ore is transported to a processing plant for extraction of bitumen using flotation processes. The ore displays considerable variability in clay, bitumen, and fines which affects their behavior in flotation units. Using oil sand ore spanning a range of bitumen and fines characteristics, flotation experiments were performed to generate froth in a batch extractor to determine ore processability (e.g., separation performance) and froth characteristics (color, bitumen, solids). From hyperspectral observations of ore, models can predict the %bitumen content and %fines (particle passing at 44 and 3.9 µm) of ore but the models with highest r2 (>0.96) predict the solids/bitumen of froth and the processability of ore. Spectral observations collected on ore upstream of the separation vessels could therefore offer a first order assessment of froth quality for an ore blend before the ore enters the plant. These models could also potentially be used to monitor and control the performance of the blending process as another means to control the performance of the flotation process. [ABSTRACT FROM AUTHOR]

The traditional organic index can be greatly affected in the areas with high thermal evolution degree whilst combination of REE for oil-source correlation will improve the results. In addition, Re-Os dating is a quantitative method of geochronology, but the significance of the test results is quite controversial. In this paper, REE geochemical analysis and Re-Os dating of bitumen in the Banjie paleo-oil reservoir is carried out. The REE distribution pattern of bitumen was compared with that of the main source rocks in the area using the method of grey correlation. Results show that the ΣREE of bitumen in the Banjie paleo-oil reservoir is low, and the fractionation of light and heavy REEs is obvious, showing a weak negative Ce anomaly and an obvious negative Eu anomaly, which indicates that the bitumen was formed in a reducing environment and has not experienced any strong weathering or leaching. The REE distribution mode belongs to the right-leaning mode of LREE enrichment. The REE distribution pattern curve is similar to that of Devonian source rocks in this area, indicating a genetic relationship. The results of Re-Os dating show that the Re-Os model age of bitumen in the Banjie paleo-oil reservoir ranges mainly from (203.6±1.1) Ma to (238.5±4.2) Ma, with an average of (224.8±3.3) Ma (n=7). The last factor which disturbed the Re-Os system of the bitumen is the process of bitumen generation. The model age represents the age of bitumen formation in the Banjie paleo-oil reservoir, when oil was cracked into gas.

CO 2 emissions from bitumen upgrading represent a major source of greenhouse gas emission in the oil sands industry of Canada. In this paper, optimal design of bitumen upgrading plant was studied with the aim of CO 2 reduction. Various CO 2 capture techniques including oxyfuel combustion, pre–combustion and post–combustion are modeled and incorporated into an integrated optimization model for simultaneous design of bitumen upgrading plant and the associated utility plant. To solve the resulting large-scale mixed integer nonlinear programming (MINLP) problem, augmented Lagrangian decomposition method is used. Optimal configurations under different scenarios (including plant capacity, natural gas, electricity and crude oil prices, and carbon tax) are discussed. The key findings of this study include: (i) hydrocracking for bitumen upgrading is favored, (ii) producing extra power and high–quality duty with a gas turbine burning natural gas is beneficial, and (iii) carbon capture with pre–combustion technology is suggested. [ABSTRACT FROM AUTHOR]

In the roadworks sector, extraction is a crucial step that consists of separating the bituminous binder from the mineral matter in asphalt mixture or reclaimed asphalt using a chlorinated solvent before the characterisation of binders' properties and content. This review, conducted on scientific articles, technical papers and standards from 1996 to 2016, combined all existing bitumen extraction/recovery methods to toxicological data and health concerns as well as inputs on circular economy and sustainability of solvents. Nearly 50% of the documents dated from 2001 and found in this study deal with these latest aspects. There are ten different methods for extracting and two methods for recovering bituminous binders using eight of the most common solvents. One crucial point highlighted by the literature is that the nature of solvent has a significant impact on the final properties of the recovered binder. The quality of extraction and binder recovery operations largely depends on the solubility of the binder in relation to the solvent. According to the calculated Hansen solubility parameters, the lowest relative energy difference parameters (solubility study) are obtained using perchloroethylene, 1,1,1-trichloroethane and xylene solvents. This means that these solvents are the most compatible with bitumen. There is a relationship between the relative energy difference and the octanol/water partition coefficient currently used in the environmental risk assessment. All the Strengths, Weaknesses, Opportunities, Threats of different extraction and recovery methods currently in use highlights the fact that at this time, there are no alternative products that are as effective under the current technical conditions of use as chlorinated solvents. This represents a challenge for new research in the trade industry and in health institution to find a substitute for chlorinated products that meets all the sustainability and circular economy criteria. [ABSTRACT FROM AUTHOR]

This paper outlines a method for evaluating environmental assessment (EA) systems called the environmental assessment system evaluation method. The method consists of five steps: (1) develop an initial list of good practices based on a literature review; (2) validate and adjust the practices by surveying experts and stakeholders; (3) describe the EA system; (4) use the good practices to evaluate the EA system through surveying EA participants and reviewing relevant documentation; and (5) identify changes to address deficiencies. The method provides a comprehensive and transparent evaluation that identifies strengths and weaknesses and means of improvement. The evaluation method is tested by applying it in a case study evaluation of the EA system for bitumen development in Canada. [ABSTRACT FROM AUTHOR]

In this paper, studies on the modification on the low temperature coal tar pitch extracted from coal tar residue in Inner Mongolia are conducted. First, the low temperature coal tar pitch in liquid state is solidified with a higher softening point by chemical crosslinking modification. The modified coal tar pitch can achieve the standard pavement performance requirements. Then, the effects of chemical crosslinking agent and physical modification additives on the mechanical performance and toxic properties of coal tar pitch are investigated. The detoxification mechanism is also studied, which further promote the applicability of modified low temperature coal tar pitch in the pavement constructions. [ABSTRACT FROM AUTHOR]

To obtain modified bitumen with excellent adhesive properties, coumarone-indene resin (CIR) was used. However, bitumens modified by CIR have somewhat worse plastic properties. For the improvement of the plastic properties of road bitumen modified by coumaroneindene resin, the paper proposes to use plasticizers. Characterized by a high content of rings (aromatic-naphthenic oils), a range of compounds was used as plasticizers. Of all different plasticizers tested, the tar produced from West-Ukrainian oils has been found to be the most effective one. The optimal ratio between modified bitumen components was determined enabling to obtain the commercial product of polymers modified bitumen of BMP 60/90-52 brand. The complex thermogravimetry and differential-thermal analysis has been used to analyze the initial and modified bitumen. Bitumens modified by CIR have shown by far the highest thermal stability under operation conditions. [ABSTRACT FROM AUTHOR]