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The production process of the traditional paper making process produces a large amount of waste water, known as paper black liquor. It is needed to explore new ways of reusing this waste and replacing part of the base bitumen to reduce the consumption of non-renewable resources, such as petroleum, thus obtaining better environmental, economic, and social benefits. This paper analyses the feasibility of using paper black liquor, which contains a large amount of lignin, as a modifier for bitumen in the paper industry. Samples of modified bitumen were prepared with 15%, 30%, and 45% of the base bitumen replaced by paper black liquor, and a control group of base bitumen was prepared for testing. The samples were subjected to an 85 min short-term ageing test, FTIR scanning test, thermogravimetric test, frequency scanning test, MSCR test, and LAS test. The analysis of the FTIR and thermogravimetric tests showed that the paper black liquor was mainly composed of lignin and some cellulose, and contained a small amount of salts with Na ions; based on the results of the frequency scan, the compatibility analysis of the vGP curve showed that the modified bitumen was more compatible in the high-temperature range after short-term ageing, thus inferring that the water content of the concentrate had an influence on the compatibility, making it necessary to further investigate different optimum water contents to achieve the best performance and benefit. The incorporation of paper black liquor improved the rutting resistance and fatigue resistance of the modified bitumen, and also gave the paper-black-liquor-modified bitumen a better ageing resistance than the base bitumen. While demonstrating the feasibility of using paper black liquor as an bitumen modifier, this study also helps to provide a basis for theoretical applications of biomass materials in the field of road engineering. [ABSTRACT FROM AUTHOR]

Scientists have effectively demonstrated that the introduction of a waste product comprising cementitious chemical compositions can enhance the mechanical properties and durability of cold bitumen emulsion mixes (CBEMs). On the other hand, the high air void content of the CBEM mix remains a challenge that is considered unsatisfactory by paving engineers. As a result, this investigation highlights two major changes that were made. The first is the use of waste paper sludge ash (PSA) as a filler in CBEM instead of the conventional mineral filler (CMF). The second change was made to further improve the mixture by reducing the amount of CBEM air voids using microwave (MW) heating energy as a post-treatment method. When compared to typical hot mix asphalt (HMA), the new CBEMs showed great mechanical properties and durability. Moreover, the proposed method, using CBEMs, has lower environmental risks, is safer, and is more cost-effective than existing paving mix technologies. This study presents a method for controlling air voids within pavement specifications without affecting mechanical behaviour or generating additional environmental or economic considerations. When compared to typical mixtures, laboratory test results showed that MW-heating can enhance both the stiffness modulus and the air void content. Furthermore, these results revealed a minor reduction in creep stiffness and water sensitivity. Nevertheless, in terms of mechanical, volumetric, and economic properties, the suggested post-mix treatment was comparable to HMA. The findings point to the need to adopt CBEM post-heating approaches, particularly the MW treatment procedure. [ABSTRACT FROM AUTHOR]

The article discusses the case study of using bitumen paper pipes in the sluicing industry in Victoria in the early 1860s. Topics include the use of pipes for water collection and distribution in the Victorian goldfields, the unreliability of the new bitumen pipes in water supply networks and how sluicing companies abandoned the experiment after their unsatisfactory performance, and the invention of bitumen paper pipes as water infrastructure development was growing in the area.

In this study, a critical evaluation and the benefits of using a waste and a virgin polymer in an asphalt mixture are presented. The present paper is the result of a three-year research effort to find a suitable recyclate compatible with asphalt binder and setting reaction conditions in the preparation of asphalt mixtures with the mentioned recyclate. This suitable candidate was recycled low-density polyethylene (LDPE), which was produced by recycling old, worn-out bags and films. An amount of 6% of LDPE by the weight of the binder content was suggested as the best amount of the modifier. Physical tests, including penetration, softening point, and kinematic viscosity have been carried out to prove the effectiveness of the modification on the binder properties. The effectiveness of the blending process and the appropriate concentration of additives led to a homogeneous polymer-modified bitumen without any imperfections in the structure. After successful preparation under laboratory conditions, this paper describes the preparation of asphalt mixtures directly in an asphalt-mixing plant and the subsequent implementation of a verification section. The overall composition of prepared polymer-modified asphalt mixtures has been studied. An important result of this study is the preparation of the asphalt mixture with waste LDPE that meets all the technical requirements. Moreover, it has been proven that this type of waste PE is fully applicable in asphalt-mixing plants in Slovakia, with zero or minimal financial burden on construction companies to complete the construction of their production facilities. Using such a technology, we can reduce the amount of waste plastics that otherwise end up in landfill. [ABSTRACT FROM AUTHOR]

Bitumen membranes have a primarily waterproofing function in the construction industry. The waterproofing function in bitumen membranes is provided by the mas of bitumen. The amount of bitumen mass can be determined by various methods. This paper deals with the determination of the bitumen mass in bitumen membranes by means of extraction and calcination. In the current legislation, the quantity of bitumen mass can only be determined by extraction. The calcination method is specified in the forthcoming EN 544, which is used for bitumen shingles. Previous research by the author has shown that the methodology from this standard cannot be used. The aim of this paper is to provide a practical verification of the extraction and calcination methods from previous author's research on a set of selected bitumen membranes. A total of 6 bitumen membranes were used for comparison. The bitumen membranes were of the same type from different manufacturers. The bitumen membranes were extracted in xylene. Calcination was carried out at 600°C. Two claims were made that confirmed the results of previous research on the bitumen coating and bitumen membranes. The first claim was that the calcination method is as time consuming or faster. This claim was confirmed. The second claim was that the results between extraction and calcination would differ by a maximum of 1.3%. The second claim was only partially met because the two asphalt strips contained insoluble but burnable parts. The results therefore differed by more than 1,3 %. [ABSTRACT FROM AUTHOR]

Physical and chemical indicators of bitumen quality of grade BND 70/100 with the added carbon nanopowder 2% by weight have been studied by laboratory test methods and analysis. High reaction ability of nanopowder particles and concentration of excess surface and internal energy in them have been determined, which provide the increase of low-temperature resistance, aggregate strength, and improvement of rheological properties of nanostructured bitumen. Essential structure variation has been proved: the increase of asphaltenes and oils content for 9% and 7.2% respectively due to the decrease of resins for 16.2% by weight. Methods have been discussed for preparing a liquid nanocarbon mix, adding of the mix into bitumen and homogenization of the bitumen. Some economic indicators have been represented which influence essentially the reduction for the cost value of the nanostructure bitumen. [ABSTRACT FROM AUTHOR]

The proportion of reclaimed asphalt pavement (RAP) bitumen that gets activated and coats the virgin aggregate during the initial stage of plant production of RAP mixes, in which the RAP material is initially mixed with superheated virgin aggregate, designated as the degree of RAP bitumen activity (DoA), is an important parameter influencing the quality and performance of the RAP mix. DoA is influenced by a variety of mix and process parameters. This paper presents an empirical model, developed using the results from a previous experimental investigation and those obtained from the additional experiments conducted in the present investigation, for prediction of the DoA of RAP binder under varying combinations of mix and process variables. The experimental investigation involved mixing separately identifiable size fractions of RAP material (1.18 to 4.75 mm) and virgin aggregate (9.5 to 26.5 mm) and measuring the quantity of RAP bitumen transferred to virgin aggregate to estimate the DoA. The 41 sets of experimental data considered for the development of the empirical model covered different RAP material proportions (15% to 75%), RAP binder quality (softening point of 69°C to 78°C), RAP binder content (4.0% to 6.0%), mixing duration (0.5 to 3 min), mixing temperature (70°C to 180°C), and superheating temperature of virgin aggregate (155°C to 197.5°C). The gradation and shape of the RAP material used in different coating experiments were also different. Additional experiments were carried out in the present investigation to study the effect of superheating temperature of virgin aggregates. DoA decreased exponentially with RAP bitumen stiffness and RAP content, whereas it increased with mixing temperature, mixing time, RAP bitumen content, and the proportion of coarser RAP material. The superheating temperature of virgin aggregate did not affect DoA significantly. A regression model was developed for estimation of DoA with reasonable accuracy without having to carry out the coating experiments. Such a predictive model is useful for obtaining inputs for the estimation of the quality of final binder blend in the RAP mix. [ABSTRACT FROM AUTHOR]

New requirements for the operational reliability of roads make the utilization of polymer-modified bitumen (PMB) more common in road construction. The application of polymer-modified bitumen based on traditional technology for the production of asphalt mixtures is associated with technological and economic difficulties and does not provide proper adhesion to the mixture's mineral components. In addition, the method of producing a binder over a long time at high process temperatures leads to increased aging, which significantly reduces the service life of the material in the pavement. This paper presents the results of studies on the effect of polymer–bitumen concentrate (PBC) consisting of styrene–butadiene–styrene, plasticizer, and surfactant on the bitumen characteristics. It has been established that the use of PBC in the bitumen binder leads to an increase in the temperature range of plasticity, softening temperature, elasticity, and cohesive strength with a decrease in the viscosity of the modified bitumen. With a complex modifier rational content of 8% by weight of bitumen, the temperature range of plasticity is 79 °C, and elasticity is 82%, which exceeds the parameters of the factory PMB-60 based on SBS polymer. Tests of binders using the Superpave method allow classifying the modified binder to the PG 64-28, which shows an increase in the temperature range of viscoelastic properties by 6 °C compared with the binder produced by traditional methods. Thus, the expediency of using a complex additive containing a polymer and surface-active substances (surfactants) that can be distributed in bitumen without the use of a colloid agitator and plasticizer has been proven to improve the quality of an organic binder. [ABSTRACT FROM AUTHOR]

Physical hardening (PH) is an important factor affecting the low-temperature performance of bitumen. At present, most PH characterizations are performed by the bending beam rheometer. To present an alternative method based on the Dynamic Shear Rheometer (DSR) equipment, this paper explores the possibilities of the 4 mm plate-plate test to investigate PH in bitumen. A variety of binders was selected, differing in their content of natural waxes, in crude origin, and production procedure. An aged sample was also included. The results show that a 20 min equilibrium period is sufficient to stabilize the sample temperature. To evaluate the PH, a time follow-up of 4 h was selected, as after 4 h the change in slope of complex modulus versus time drops below 1%. Further conclusions show that the physical hardening index (PHI) of bitumen is temperature- and frequency-dependent. This PHI is largest at 0 °C and increases when tested at lower frequencies. The non-waxy binder had almost no hardening, while the waxy binders showed evident hardening. Although the presence of wax is an important factor, the PHI of these binders is not directly related to the total wax content, which was determined by differential scanning calorimetry. In conclusion, the findings show that 4 mm DSR tests provide an effective approach to characterize PH of bitumen. [ABSTRACT FROM AUTHOR]

Thermal recovery techniques for producing oil sands have substantial environmental impacts. Surfactants can efficiently improve thermal bitumen recovery and reduce the required amount of steam. Such a technique requires solid knowledge about the interaction mechanism between surfactants, bitumen, water, and rock at the nanoscale level. In particular, oil sands ores have extremely complex mineralogy as they contain many clay minerals (montmorillonite, illite, kaolinite). In this study, molecular dynamics simulation is carried out to elucidate the unclear mechanisms of clay minerals contributing to the bitumen recovery under a steameanionic surfactant co-injection process. We found that the clay content significantly influenced an oil detachment process from hydrophobic quartz surfaces. Results reveal that the presence of montmorillonite, illite, and the siloxane surface of kaolinite in nanopores can enhance the oil detachment process from the hydrophobic surfaces because surfactant molecules have a stronger tendency to interact with bitumen and quartz. Conversely, the gibbsite surfaces of kaolinite curb the oil detachment process. Through interaction energy analysis, the siloxane surfaces of kaolinite result in the most straightforward oil detachment process. In addition, we found that the clay type presented in nanopores affected the wettability of the quartz surfaces. The quartz surfaces associated with the gibbsite surfaces of kaolinite show the strongest hydrophilicity. By comparing previous experimental findings with the results of molecular dynamics (MD) simulations, we observed consistent wetting characteristics. This alignment serves to validate the reliability of the simulation outcomes. The outcome of this paper makes up for the lack of knowledge of a surfactant-assisted bitumen recovery process and provides insights for further in-situ bitumen production engineering designs. [ABSTRACT FROM AUTHOR]

Copyright of Roads & Bridges / Drogi i Mosty is the property of Road & Bridge Research Institute 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.)

This paper evaluates the strength performance of hot mix asphalt produced with High Density Polyethylene (HDPE)-modified bitumen and Reclaimed Asphalt Pavement (RAP) which is partially replacing virgin aggregates. Asphalt Institute blending chart was used to determine the quantity of Reclaimed Asphalt Pavement (RAP) incorporated into the mixture. Thermo-gravimetric Analysis and Differential Thermal Analysis (TGA/DTA) were used to determine thermal stability of the High Density Polyethylene (HDPE). Fourier Transform Infrared (FTIR) was used for characterization of the HDPE, bitumen and modified bitumen. Physical test conducted on the RAP and virgin aggregates in accordance with American Society of Testing Materials (ASTM) standards revealed that the aggregates are adequate for use in asphalt production. Marshall method of mix design was adopted for the hot mix asphalt production and testing. With respect to the threshold, the results of Marshall stability showed a 6% increase in the strength of the asphaltic mixture modified with 10% High Density Polyethylene (HDPE). Other Marshall properties tested also showed improvements. Scanning Electron Microscopy and Energy Dispersive X-ray Spectrometry (SEM/EDS) were used for micro-structural examination and composing elements analysis of the asphaltic mixture, respectively. Fibermetric analysis was used to explore the fiber content and pores within the mixture. [ABSTRACT FROM AUTHOR]

This study examines the applicability of an unknown composition waste plastic bag sample as bitumen modifier. The waste components were initially characterized to identify the type of plastics and the level of impurity. Asphalt binder performance was examined for rutting, thermal, and age resistance. The results revealed that the waste plastic bags, predominantly consisted of Low-Density Polyethylene (LDPE) and Linear Low-Density Polyethylene (LLDPE) and contained 6.1% impurities. The binder tests indicated that the waste plastic bags enhanced the rutting resistance of bitumen by one grade, with its modification more similar to LLDPE, rather than LDPE. The thermal degradation and aging properties of the modified binders demonstrated that the bitumen modified by the waste plastic bags exhibited slightly lower resistance to temperature and aging compared to virgin LDPE and LLDPE. This was attributed to the impurities contained in the waste plastic. In conclusion, the analyzed waste plastic bags proved to be suitable for use in binder modification, presenting a viable alternative to virgin LLDPE. [ABSTRACT FROM AUTHOR]

This paper describes laboratory experiments and presents results for the performances of cold-mix, cold-lay emulsion mixtures. The main objective of the experiments was to evaluate and improve the properties of the cold mixtures. The mixture properties evaluated were: volumetric properties, indirect tensile stiffness modulus (ITSM), repeated load axial creep and fatigue. These properties were compared with conventional hot asphalt mixtures not containing any waste/recycled materials. To optimise the performances of the mixtures, a target of ITSM value of 2000 MPa was selected. At full curing conditions, the stiffness of the cold mixes was found to be very similar to that of hot mixtures of the same penetration grade base bitumen (100 pen). Test results also show that the addition of 1-2% cement significantly improved the mechanical performance of the mixes and significantly accelerated their strength gain. The fatigue behaviour of the cold mixes that incorporated cement was comparable with that of the hot mixtures. The Webb Prize, presented for the best paper on a transport- or rail-related subject, was awarded to: Li CN and Lai TY (2009) Why should cities change from DOT to TOD? Proceedings of the Institution of Civil Engineers - Transport, 162(2): 71-78. Transportation systems and cities that are connected by development- oriented transit (DOT) should be reconnected under the newer concept of transit-oriented development (TOD). This paper examines the reasons why cities should progressively change from DOT to TOD. The literature was reviewed to examine the urban history of DOT and TOD and the aims of TOD were identified. The relationship between sustainable development and concepts of TOD was then established to show why cities should change from DOT to TOD. It was also concluded that the concepts of TOD match sustainable development. Finally, extended strategies of TOD were established for Taipei City in the two specific perspectives of the transport system and land use [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the effect of high viscosity petroleum resin (HV-PR) on the microstructure and macro properties of styrene–butadiene–styrene block copolymer (SBS) modified bitumen. SBS modified bitumen was prepared with different content of HV-PR in this paper. The microscopic images were obtained by fluorescence microscope and were analyzed qualitatively and quantitatively with MATLAB and image-pro software. The dynamic shear rheometer test was used to study the dynamic shear properties of SBS modified bitumen with different HV-PR content. The effect of different HV-PR content on the aging resistance of the modified bitumen was studied. The other technical properties of SBS modified bitumen with different HV-PR content, such as segregation softening point difference etc. were also tested. The research results show that: HV-PR can help SBS to be sheared into smaller particles during the shearing process, effectively improve the swelling degree of SBS modifier, improve the spatial distribution of cross-linking structure, and form a more compact cross-linking structure. The addition of HV-PR can effectively improve the high-temperature deformation resistance and fatigue damage resistance of SBS modified bitumen, the higher the HV-PR content, the more obvious the improvement effect. The addition of HV-PR can also significantly reduce the loss of ductility and the gain of viscosity of SBS modified bitumen during the long-term aging process. The higher the HV-PR content, the more significant the effect. HV-PR can effectively improve the viscosity, low-temperature performance, and storage stability of bitumen. [ABSTRACT FROM AUTHOR]

In recent times, circular economy initiatives in addition to the need for sustainable biomaterials have brought about several attempts at the eco-friendly, eco-sustainable and cost-effective production of asphalt pavements. It is an increasingly common practice in the asphalt industry to improve road pavement performance using additives to enhance the physico-chemical properties of bitumen, which performs the role of the binder in the asphalt mix. This paper evaluated the potential of a bio-based additive derived from olive leaf residue as a modifier and antioxidant agent for bitumen. Samples of neat, aged and doped aged bitumen were analyzed. In this study, the two bio-based additives were characterized in terms of phenol, chlorophyll, lignin and cellulose content, which was correlated with the mechanical properties of the tested samples. The mechanical properties of the neat, modified, aged and unaged samples were evaluated via Dynamic Shear Rheology. The bio-based additives proved to be promising and can improve the properties of bitumen binder and the performance of asphalt pavements in general. [ABSTRACT FROM AUTHOR]

Linear amplitude sweep tests have been demonstrated to have good potential in being used for the evaluation of self-healing properties of neat and polymer-modified bituminous binders. Past research works, however, have neglected the effects of material non-linearity and thixotropy. This implies that the whole material integrity loss is attributed to damage and all restoration to self-healing, thus resulting in the possible overestimate of both damage and self-healing when evaluating the fatigue performance of materials. In the study described in this paper, specific experimental and analytical methods were adopted with the purpose of separating non-linearity and thixotropy in LAS healing tests. Non-linearity was assessed by means of multiple strain sweep tests carried out to determine the material non-linear viscoelastic moduli at specific testing temperatures. Thixotropy was considered by coupling self-healing LAS testing with a purposely defined test in which loading was applied to the undamaged material after a rest period equal to that applied in self-healing tests. Obtained results were processed by means of an analytical approach based on the simplified viscoelastic continuum damage model. Quantification of self-healing included the determination of material integrity and damage parameters recovered after the rest period. Such parameters, calculated by excluding time-dependent and non-linear biasing effects, can be used as straightforward indicators of the self-healing potential of neat and polymer-modified bituminous binders. Moreover, obtained results substantiate the concept that time–temperature superposition is still applicable when non-linearity is incorporated into the simplified viscoelastic continuum damage model. [ABSTRACT FROM AUTHOR]

Improving the aging resistance of waterproof membranes is very important to extend their service life. In this paper, organic montmorillonite (OMMT) was used to enhance the aging resistance of styrene-butadiene-styrene (SBS) modified bitumen (SMB) for waterproofing. The effect of OMMT on the physical properties, chemical structure, and micromorphology of SMB membranes before and after heat aging were investigated, and the service life of the SMB membranes was predicted based on the Arrhenius model. The results indicated that the high- and low-temperature performance of SMB was improved due to the addition of OMMT, and the optimal dosage of OMMT was 3%. After 20 days of heat aging at 80°C, the alterations of softening point increment, low-temperature flexibility decrement, and viscosity aging index of OMMT/SMB decreased by 1.5°C, 3°C, and 14.7%, respectively, compared with that of SMB, which indicated that OMMT can enhance the aging resistance of SMB waterproof membranes. Fourier-transform infrared spectroscopy indicated that the change of IC═O , IS═O , and IC═C of 3% OMMT/SMB was 53.5%, 45.6%, and 53.2% less, respectively, than SMB after 20 days of heat aging at 80°C, which shows that OMMT can inhibit the change of carbonyl, sulfoxide, and butadiene double bonds of SMB. The gel permeation chromatography showed that OMMT can hinder the degradation of SBS and polycondensation of bitumen during heat aging. The fluorescence microscope showed that OMMT/SMB maintained a more complete network structure than SMB after heat aging. According to the Arrhenius model, based on the 0°C flexibility as the damage point and the temperature of waterproof materials under sunlight being 60°C for an annual sunshine time of 1,200 h, the service life of SMB and OMMT/SMB were predicted to be 16.90 and 21.32 years, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department 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.)

Non-renewable nature and continuously increased consumptions of bitumen is a serious challenge for the development of infrastructure, especially for the constructions and maintenances of asphalt pavements. To cope with this situation, some sustainable strategies are needed. Extensive efforts have been made to improve the resilience, sustainability and circularity of asphalt pavements. Among them, the utilisation of bio-based materials is one of the most promising measures. This paper systemically reviewed the state-of-theart knowledge in the development of bio-bitumen. Wood-based oils, waste cooking oils and manure-based bio-bitumen were selected as the review objectives. It was revealed that all bio-based oils currently being used are more suitable for serving as additives like softeners, rejuvenators, or modifiers rather than as alternative of binders. One of the most promising utilisations of biooils is as rejuvenators, potentially antioxidants as well. Incorporating polymers with bio-oils is another feasible practice to improve the performance of biobitumen. Causation should be taken when producing bio-based bitumen since compatibility might have some kind of influence on the performance and this issue should be addressed carefully. [ABSTRACT FROM AUTHOR]

In the preparation of high-performance polyurethane (PU) modified bitumen, due to the different kinds of PU modifiers, the design parameters of the preparation process are numerous, and indexes of the performance response need to be selected. As a result, the preparation process of PU-modified bitumen is not universally applicable. Therefore, according to different application environments, how determining the process parameters of the PU-modified bitumen accurately and efficiently is a key problem to be solved urgently. Based on fthe Kriging-PSO hybrid optimization algorithm, this paper proposed a novel design method for the preparation process for the PU-modified bitumen. The response indicators with high relative sensitivity (softening point, rutting factor, Brookfield viscosity, and dispersion coefficient) were screened by using range and variance analysis to improve the fitting accuracy of the Kriging-PSO model after training. Among them, the dispersion coefficient was evaluated by fluorescence microscopy test using the Christiansen coefficient method to evaluate the uniformity of the dispersed phase of the PU modifier. Through the Kriging-PSO algorithm, the main process parameters for preparing PU-modified bitumen in the laboratory were determined as follows: shearing time 86 min, shearing speed 2450 rpm, shearing temperature 148, and PU content 18.6%. The prepared PU-modified bitumen was placed in an oven at 100 for 2 h. The performance indicators of PU modified bitumen were: softening point 90, rutting factor 30 kPa, Brookfield viscosity 80,000 Pa·s, and dispersion coefficient 0.92. The PU-modified bitumen prepared by this optimal process met the expected performance indicators. The results of this paper showed that the Kriging-PSO algorithm provided a new idea for the design of a modified bitumen preparation process and achieve the purpose of designing the optimum process parameters of PU modified bitumen efficiently using fewer samples. Meanwhile, it created a new way for the application of machine deep learning algorithms in the civil engineering field. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to present the development of a new predictive model intended for the calculation of stiffness modulus |E*| determined by a four-point bending beam test (4PBB or 4PB-PR). The model developed, called model A, was based on the Witczak model, which was developed for the dynamic-modulus (DM) method. Most of the asphalt mixtures used to develop the model were high-modulus asphalt concrete (HMAC). The most commonly used methods for determining the stiffness modulus |E*| of asphalt mixtures were also discussed. The paper presents the results of the study for 10 asphalt mixtures but 8 of them were used to develop the predictive model. In addition, the results of complex shear modulus G* tests on neat and modified bituminous binders carried out in a dynamic shear rheometer (DSR), necessary for the development of a predictive model, are presented. The tests carried out in the dynamic shear rheometer had significant measurement uncertainties. The results of the volumetric parameters of the asphalt mixtures are also reported. The developed model A has maximum absolute errors e = 1930 MPa (p = 95%) and maximum relative errors re = 50% (p = 95%). The distribution of the absolute errors of the model, after discarding outliers, has a normal distribution as in the development of other models of this type, which was confirmed by appropriate statistical tests. On the basis of the tests and calculations carried out, it was concluded that, in order to increase the precision of the predictive models, it is advisable to reduce the measurement uncertainty of the bitumen complex shear modulus G*. For the developed model A, the limiting values of the stiffness modulus |E*| are also shown, within which the determined stiffness modulus should fall. [ABSTRACT FROM AUTHOR]

Conventional bitumen pavement is no longer suitable for handling increasing loads and weather variations, which cause road deterioration, Thus, the modification of bitumen has been suggested to counter this issue. This study provides a detailed assessment of various additives for modifying natural rubber-modified bitumen used in road construction. This work will focus on the use of additives with cup lump natural rubber (CLNR), which has recently started to gain attention among researchers, especially in rubber-producing countries such as Malaysia, Thailand and Indonesia. Furthermore, this paper aims to briefly review how the addition of additives or modifiers helps elevate the performance of bitumen by highlighting the significant properties of modified bitumen after the addition of modifiers. Moreover, the amount and method of application of each additive are discussed further to obtain the optimum value for future implementation. On the basis of past studies, this paper will review the utilisation of several types of additives, including polyphosphoric acid, Evotherm, mangosteen powder, trimethyl-quinoline and sulphur, and the application of xylene and toluene to ensure the homogeneity of the rubberised bitumen. Numerous studies were conducted to verify the performance of various types and compositions of additives, particularly in terms of physical and rheological properties. In general, additives enhance the properties of conventional bitumen. Future research should investigate CLNR because studies on its utilisation are limited. [ABSTRACT FROM AUTHOR]

Low-temperature cracking is one of the most common failures in asphalt pavements, especially in cold regions. Accordingly, considerable amount of research has been performed in order to understand the low-temperature cracking mechanisms and to propose test methods for characterizing and determining cracking performance of bitumen and asphalt mixtures under freezing conditions. The existing test methods, however, require expensive equipment and skilled technicians; they are thus not well suited for routine tests. As a contribution to mitigate this situation, this study intends to investigate experimentally and characterize numerically the low-temperature cracking behavior of bitumen and mastic materials using a refined thermal cracking test method. The proposed method, the annular restrained cold temperature induced cracking (ARCTIC) test, allows to determine the low-temperature cracking properties of the mastic and bitumen with a relatively simple setup. In this paper, finite element (FE) modeling is used for evaluating the effect of test parameters on the temperature, stress and strain gradients induced in the specimen during the test. The ARCTIC test is employed to measure cracking temperatures of two bitumen and two mastic materials. The measurements repeatability is examined and the effect of bitumen type on the thermal cracking potential of bitumen and mastic is evaluated. FE modeling is employed to examine the effect of thermomechanical parameters on thermal cracking performance of the materials and to back-calculate fracture stress and strain from measurements. The results highlight the potential of the proposed test and analysis method for evaluation of low-temperature cracking in bitumen and asphalt mastic. [ABSTRACT FROM AUTHOR]

Enhanced oil recovery (EOR) processes are technologies used in the oil and gas industry to maximize the extraction of residual oil from reservoirs after primary and secondary recovery methods have been carried out. The injection into the reservoir of surface-active substances capable of reducing the surface tension between oil and the rock surface should favor its extraction with significant economic repercussions. However, the most commonly used surfactants in EOR are derived from petroleum, and their use can have negative environmental impacts, such as toxicity and persistence in the environment. Biosurfactants on the other hand, are derived from renewable resources and are biodegradable, making them potentially more sustainable and environmentally friendly. The present review intends to offer an updated overview of the most significant results available in scientific literature on the potential application of biosurfactants in the context of EOR processes. Aspects such as production strategies, techniques for characterizing the mechanisms of action and the pros and cons of the application of biosurfactants as a principal method for EOR will be illustrated and discussed in detail. Optimized concepts such as the HLD in biosurfactant choice and design for EOR are also discussed. The scientific findings that are illustrated and reviewed in this paper show why general emphasis needs to be placed on the development and adoption of biosurfactants in EOR as a substantial contribution to a more sustainable and environmentally friendly oil and gas industry. [ABSTRACT FROM AUTHOR]

The paper considers approaches, principles, and results of modeling the quality parameters of petroleum bitumen using machine learning algorithms based on recurrent neural networks. It is shown that machine learning algorithms can be effectively used in practice for oil refining processes. Various problems involved in data processing, as well as selection of variables and suitable neural network architecture for solving a particular problem, are considered. Further research directions are outlined. [ABSTRACT FROM AUTHOR]

This paper analyses the key findings of a study devoted to PET-modified bitumen. The research program was run according to the D-optimal experimental plan based on a factorial design. Five factors, i.e., the type of polymer (source), the type of bitumen (qualitative factors), PET amount, mixing rate, and mixing temperature (quantitative factors), controlled the bitumen–polymer mixing process. The experiment included a series of determinations of bitumen's rheological characteristics obtained by MSCR (Jnr, R) and G*/sin(δ) at 50 °C, 60 °C, and 70 °C. The low-temperature properties of the composite (critical temperature) were evaluated using a BBR test. The findings showed that bitumen modification with PET primarily reduced the creep susceptibility of the bituminous–polymer mixture. The low-temperature characteristics of the modified bitumen played a secondary but essential role. The amount of polymer and the mixing rate interacted with the temperature, significantly reducing the stiffness of the composite, while the type and amount of bitumen had a substantial effect on the results obtained in the BBR test. It is worth noting that when combining bitumen and plastomer, special attention should be paid to ensuring a high level of homogeneity of the mixture by controlling the parameters of the mixing process accordingly. The tests and analyses provided crucial models (GLM), which allowed for the prediction of the plastomer-modified bitumen's low- and high-temperature properties. The resulting relationships between factors and the identification of their impact on the bitumen properties enable a better understanding of the process of bitumen modification with PET. The conclusions presented here serve as a basis for future optimisation of the modified bitumen composition. The performed studies indicate that the use of >3% plastomer in bitumen 70/100 allows for a reduction in its susceptibility (MSCR) to below 0.5 kPa−1, making it suitable for bituminous mixtures for high-traffic roads. No significant increase in critical temperature (BBR) was observed. [ABSTRACT FROM AUTHOR]

A fast-melting styrene-butadiene-styrene-based modifier (SBS-T) was applied for rapid modification for asphalt mixtures. No relevant studies are available to support the effect of this new fast-melting modifier on asphalt-aggregate adhesion properties, and this paper is to remedy the assessment of the adhesive properties of the modified SBS modifier in asphalt mixtures. At the micro-scale, the sessile drop method is utilized to measure the contact angle of bitumen and aggregate and to compute thermodynamic parameters based on surface energy theory. Meanwhile, the effects of short-term and ultraviolet (UV) aging on the thermodynamic parameters of SBS-T modified asphalt (SBS-T-MA) were investigated. The asphalt-aggregate adhesion properties were further verified on a macro-scale scale by pull-off tests. The outcomes suggested that the higher the dosage of SBS-T modifier, the better the thermomechanical characteristics of the bitumen binder. The adhesive properties of SBS-T-MA and aggregates were promoted in short-term aging and decreased in UV aging. Statistical analysis of the pull-off test indicated a significant correlation between pull-off strength and energy ratio. It was demonstrated that adhesion damage occurred between asphalt and aggregate in the pull-off test and that the greater the energy ratio between asphalt and aggregate, the greater the asphalt-aggregate pull-off strength. [ABSTRACT FROM AUTHOR]

Petroleum asphaltenes are considered the most irritating components of various oil systems, complicating the extraction, transportation, and processing of hydrocarbons. Despite the fact that the paramagnetic properties of asphaltenes and their aggregates have been studied since the 1950s, there is still no clear understanding of the structure of stable paramagnetic centers in petroleum systems. The paper considers the possibilities of various electron paramagnetic resonance (EPR) techniques to study petroleum asphaltenes and their solubility fractions using a carbon-centered stable free radical (FR) as an intrinsic probe. The dilution of asphaltenes with deuterated toluene made it possible to refine the change in the structure at the initial stage of asphaltene disaggregation. From the measurements of samples of bitumen, a planar circumcoronene-like model of FR structure and FR-centered asphaltenes is proposed. The results show that EPR-based approaches can serve as sensitive numerical tools to follow asphaltenes' structure and their disaggregation. [ABSTRACT FROM AUTHOR]

Athabasca bitumen is an abundant resource that has successfully been upgraded using delayed coking that typically operates at 499 °C (∼930 °F), 207 kPa (∼37 psig), 1–2 min residence time on this type of crude. With society's desire to reduce industry environmental impact while still providing energy to earth's growing population, lower energy intensive (and thus lower greenhouse gas emissions) bitumen conversion approaches have been researched and are moving towards commercialization. The paper reviews a correlative model developed on a novel thermal cracking process, operated at lower temperatures (395–405 °C (743–761 °F)), lower pressures (<69 kPa (∼<10 psig) and up to 1 h residence time versus delayed coking, that takes various lab and pilot data, both batch and continuous, as inputs into developing the model. The purpose of the model is for use in industrial operations to provide guidance to operations for representative thermal cracker performance. The model is based on the Arrhenius equation using first order reaction kinetics for easy comprehension and use in an operational environment. Data for developing the model has been taken from various literature sources in the area of study, notably by researchers, Dr. W. Svrcek, Dr. Wiehe, Dr. Mehrotra, and Dr. Yarranton. The public data is used to create a viable range of performance that includes proprietary developments with the novel thermal cracking process. The model is configured on a mass basis so that mass balance closure can be readily calculated. A range of kinetic coefficients are provided that can be used to fit commercial plant performance based on the expected range of product outputs noted in the paper. [ABSTRACT FROM AUTHOR]

Nowadays in the world, due to the constant desire for recycling, many countries are considering the use of recycled plastics on roads. Modification of bitumen for roads in Kazakhstan is considered one of the most suitable and popular approaches. This paper presents the results of research on the modification of bitumen by recycled plastics from waste materials. The paper describes the details of the use of plastic waste as bitumen modifiers, with a specific focus on recycled plastics and how they can potentially be used to enhance bitumen performance and the road durability. The main physical and mechanical characteristics of the modified bitumen were determined after routine tests, penetration and plasticity, softening temperature, brittleness temperature on Fraas and microscopic analysis. The morphology of the modified bitumen was studied using scanning electron microscopy. The results confirm that the modified bitumen complies with the requirements for polymer-bitumen binder of Kazakhstani standards and is suitable for the production of modified bitumen by its physical and chemical characteristics. [ABSTRACT FROM AUTHOR]

Roads, due to use and time, become aged and as a result, they require maintenance. This paper presents a promising technology to compensate ageing. The method uses porous aggregates as capsules containing rejuvenator. The rejuvenator will be released during the asphalt pavement's service life, reversing the impact of ageing on asphalt performance, properties and, thus, extending pavement's durability. This paper describes the properties of two porous aggregates, the encapsulation method and the properties of the capsules. The capsules were incorporated into an asphalt mix and their fundamental properties analysed. Finally, the recovery potential of the aged binder was evaluated using ageing tests. The results demonstrate the effectiveness of the technology, a change in binder properties was observed over time, but to a lesser extent for the bitumen when capsules were included than for the reference. The solution also highlights the benefits of using encapsulated rejuvenator over the use of rejuvenator directly added to the mix. [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. [ABSTRACT FROM AUTHOR]