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Oil road bitumen was modified by a copolymer of ethylene with vinyl acetate (EVA) and 3-glycidyloxypropyltrimethoxysilane (epoxysilane). These modifiers were simultaneously introduced into the BND 90/130 oil bitumen at a temperature of 165 °C. The components were mixed up during two hours with further isothermal holding at the same temperature during the required period. Epoxysilane crosslinks bitumen with EVA making it possible to obtain an immiscible bitumen polymer binder. The optimal content of EVA is 12 mph, epoxysilane -3 mph with a mixing time of 4 hours. The optimal bitumen polymer binder is characterized by the following properties: softening point of 66 °C, penetration at 25 °C = 50, penetration index of 2.15, brittleness temperature of -22 ° C. Separation is significantly reduced. NMR spectroscopy has revealed that the introduction of the binding agent to the bitumen-polymer binder does not create low-mobile structures. It allows forecasting the high binder stability during storage and transportation.

Earthquakes induced by human activities can impede the development of underground resources. Significant induced events (M5) have caused both economic and human losses. The recent ML 5.6 (MW 5.1) event near Peace River, Alberta occurs in a region of in situ bitumen recovery. We find that 3.4 cm of ground deformation was caused by reverse fault slip (∼29 cm), possibly related to Peace River Arch faulting. Events are located within the shallow basement, nearby to significant wastewater injection into Paleozoic strata. We find a statistical relationship between earthquakes and injection operations. These events were likely related to the in situ bitumen development: dominantly from wastewater disposal induced pore pressure increases, with smaller poroelastic contributions from bitumen recovery. The assessment of this earthquake as induced will likely have implications for future energy development, management, and regulation—including carbon capture and blue hydrogen. Plain Language Summary Earthquakes can be caused by underground fluid injection; cases of M5 induced events have caused damage and harm. One of the largest recorded earthquakes in Alberta (ML 5.6) occurred in a region of underground oil sand development. Here, ground shaking and deformation information are combined into an interpreted result: that ancient faults were reactivated with reverse slip. The fault slip is largely within the crystalline basement, with a small portion extending into basal sediments. Nearby injection operations dispose of petroleum‐related wastewater in these basal sediments. This earthquake was likely triggered by the injection process: injection increases pore pressure, which diffuses laterally along permeable sediments, until encountering fractured rock, which channelizes flow into the crystalline basement—the increase of pore pressure within the fault continues until reaching a critical point for slip initiation. This event likely being induced will have important implications for future operations. Key Points On 30 November 2022 one of Alberta's largest recorded events (ML 5.6, MW 5.1) occurred in a region of in situ bitumen recovery A well oriented fault was reactivated with reverse slip (29 cm), causing up to 3.4 cm of ground deformation The event was likely induced by pore pressure from disposal, with smaller poroelastic stress changes from bitumen production

As a widely accepted concept, bitumen consists of four fractions that can be distinguished by their polarity. Highly polar asphaltene micelles are dispersed in a viscous phase of saturates, aromatics and resins (maltene phase). Different concentrations of asphaltenes in the bitumen result in a range of mechanical response properties. In an interdisciplinary study the impact of the maltene phase and asphaltenes on the linear viscoelastic behavior and the microstructure of bitumen were analyzed by creep recovery testing in a DSR and by atomic force microscopy (AFM). Therefore, bitumen was separated into the maltene and asphaltene fractions and artificial bitumen samples with different, pre-defined asphaltene concentrations were produced and investigated. It was found that the artificially produced, precipitated bitumen samples can be regarded as a representative, bitumen-like material in terms of mechanical behavior and microstructure. Asphaltenes play an important role in the typical viscoelastic behavior of bitumen being mainly responsible for stiffness and elasticity. Also, their concentration appears to be correlated to the occurrence and shape of the bee-like inclusions which can be typically observed by AFM.

No. 35# bitumen was selected as matrix bitumen, and the designed dosage of SBS and TPS was added to modify the matrix asphalt with high viscosity. By detecting the dynamic viscosity at 60 °C, rotational viscosity at 170 °C, softening point, and 5 °C ductility, and analyzing the change law, it was found that when the SBS content was 5.5 %, the modification effect was obvious, but the comparison technical requirements index was still insufficient. The composite modification of matrix asphalt was carried out by mixing 5.5 % SBS with the designed dosage of TPS. The results showed that the modified asphalt prepared by blending 5.5 % SBS and 7 % TPS had the best performance indicators and met the technical requirements of high-viscosity modified asphalt.

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.

Cement bitumen emulsion asphalt (CBEA) is obtained by mixing bitumen emulsion, cement, aggregates and filler at ambient temperature. CBEA is thought to be a promising substitute for hot mix asphalt because of its low environmental impact and cost-effectiveness. Disadvantages of this material are the long time required to reach its full strength and the inadequate understanding of the hardening mechanisms. This study aims at accelerating the development of mechanical properties of CBEA by using rapid-hardening cements while at the same time gaining a deeper understanding of the role of cement in CBEA. With this purpose, cold mix asphalt mixtures with cationic and anionic emulsions and different types of cement (ordinary Portland, calcium sulfoaluminate and calcium aluminate cement) were studied by means of isothermal calorimetry, measurements of water evaporation and Marshall tests. The results indicate that both anionic and cationic bitumen emulsions may affect the initial hydration rates of the cements used but have no significant influence on their degree of hydration after a few days. The addition of calcium sulfoaluminate and calcium aluminate cement to CBEA leads to mechanical properties after 1-day curing similar to those obtained with Portland cement after 1-week curing. Cement hydration dominates the strength gain, especially for rapid-hardening cements, and the type of cement influences both the amount of bound water and the rate of water evaporation from the CBEA.

The present paper investigates the viscoelastic stress-strain responses of laboratory and plant produced warm mix asphalt mixtures containing basalt fiber dispersed reinforcement. The investigated processes and mixture components were evaluated for their efficacy in producing highly performing asphalt mixtures with decreased mixing and compaction temperatures. Surface course asphalt concrete (AC-S 11 mm) and high modulus asphalt concrete (HMAC 22 mm) conventionally and using a warm mix asphalt technique with foamed bitumen and a bio-derived fluxing additive. The warm mixtures included lowered production temperature (by 10 °C) and lowered compaction temperatures (by 15 °C and 30 °C). The complex stiffness moduli of the mixtures were assessed under cyclic loading tests at combinations of four temperatures and five loading frequencies. It was found that the warm produced mixtures were characterized by lower dynamic moduli than the reference mixtures in the whole spectrum of loading conditions, however, the mixtures compacted at the 30 °C lower temperature performed better than the mixtures compacted at 15 °C lower temperature, specifically when highest testing temperatures are considered. The differences in the performance of plant and laboratory produced mixtures were ascertained to be nonsignificant. It was concluded that the differences in stiffness of hot mix and warm mixtures can be attributed to the inherent properties of foamed bitumen mixtures and that these differences should shrink in time.

In the past years a wide discussion has been held among asphalt researchers regarding the existence and interpretation of observed microstructures on bitumen surfaces. To investigate this, the RILEM technical committee on nano bituminous materials 231-NBM has conducted a round robin study combining differential scanning calorimetry (DSC) and Atomic Force Microscopy (AFM). From this, methods for performing DSC and AFM tests on bitumen samples and determination of the influence of wax on the observed phases, taking into account thermal history, sample preparation and annealing procedure, are presented and critically discussed. DSC is used to measure various properties and phenomena that indicate physical changes such as glass transition temperature ( T g ) and phase transition such as melting and crystallization. In the case of existence of wax, either natural or synthetic, it can further indicate the melting point of wax, that could be used to determine wax content. The results from seven laboratories show that T g temperatures obtained from the heating scans are more repeatable and easier to obtain in comparison to the cooling scans. No significant difference was noted for T g ’s obtained from the first and second heating scans. AFM is an imaging tool used to characterize the microstructures on a bituminous surface. Using AFM three phases in the materials with wax could be distinguished. The changes in the phases observed with AFM for increases in temperature were correlated with the DSC curve, and it could be established that the so called “Bee” structure disappeared around the melting peak in the DSC curve. Thus, this research has confirmed the relation between the microstructures on a bitumen surface and the wax content.

The failure of bituminous pavements takes place due to heavy traffic loads and weather-related conditions, such as moisture, temperature, and UV radiation. To overcome or minimize such failures, a great effort has been put in recent years to enhance the material properties of bitumen, ultimately improving field performance and increasing the pavement service life. Polymer modification is considered one of the most suitable and by far the most popular approach. Elastomers, chemically functionalised thermoplastics and plastomers * (* Note: notwithstanding the fact that in Polymer Science the word ‘plastomer’ indicates a polymer with the simultaneous behaviour of an elastomer and plastics (thermoplastics), this paper uses the term ‘plastomer’ to indicate a thermoplastic polymer as it is more commonly found in Civil and Pavement Engineering.) are the most commonly used polymers for bitumen modification. Plastomers provide several advantages and are commonly acknowledged to improve high-temperature stiffness, although some of them are more prone to phase separation and consequent storage instability. Nowadays, due to the recent push for recycling, many road authorities are looking at the use of recycled plastics in roads. Hence, some of the available plastomers—in pellet, flakes, or powder form—are coming from materials recycling facilities rather than chemical companies. This review article describes the details of using plastomers as bitumen modifiers—with a specific focus on recycled plastics—and how these can potentially be used to enhance bitumen performance and the road durability. Chemical modifiers for improving the compatibility between plastomers and bitumen are also addressed in this review. Plastomers, either individual or in combination of two or three polymers, are found to offer great stiffness at high temperature. Different polymers including HDPE, LDPE, LLDPE, MDPE, PP, PS, PET, EMA, and EVA have been successfully employed for bitumen modification. However, each of them has its own merit and demerit as thoroughly discussed in the paper. The recent push in using recycled materials in roads has brought new light to the use of virgin and recycled plastomers for bitumen modification as a low-cost and somehow environmental beneficial solution for roads and pavements.

Several variables influence the performance of hot asphalt mixtures including reclaimed asphalt pavement (RAP). Among these, the virgin bitumen’s origin, the mix production temperature and the time the mix is kept at a high temperature between mixing and compaction play a fundamental role but are often neglected. This study aimed to quantify the negative effects associated with the improper choice of these variables. Therefore, their influence on the mechanical (indirect tensile stiffness modulus and strength, Cracking Tolerance Index) and chemical (Fourier Transform Infra-Red spectroscopy) characteristics of asphalt mixtures containing 50% RA were investigated. In particular, two rejuvenators, two types of virgin bitumen (visbreaker and straight-run), two production temperatures (140 °C and 170 °C) and three conditioning times in the oven (30 min, 90 min and 180 min) were analyzed. The results showed interesting findings that allow us to recommend selecting the virgin bitumen type carefully and to avoid excessively stressing the binder during the production of the mix.