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The discrete element method (DEM) is one of the most popular methods used to study the performance of pavement materials. However, few studies use the DEM to evaluation the damage performance of asphalt overlays on cement pavements. This paper focuses on the establishment of discrete element models to simulate the reflective crack development of asphalt overlays on cement pavement. Three contact models are selected to realise the pavement structure layer. The results show that under flexural tensile loading and shear loading, the development of reflective cracks can be inhibited with increasing asphalt overlay thickness, while the influence of the interlayer bond strength on the crack development is not obvious. In addition, the flexural tensile load can promote the development of cracks more than shear load. Under the action of thermal fatigue stress, the opening degree of crack displacement increases with the fatigue stress ratio, while the increase in interlayer bond strength can slow down the development and expansion of cracks. Moreover, thermal fatigue stress causes reflective cracks in the overlay to develop earlier and faster. [ABSTRACT FROM AUTHOR]

Automatic classification of arteries and veins (A/V) in fundus images has gained considerable attention from researchers due to its potential to detect vascular abnormalities and facilitate the diagnosis of some systemic diseases. However, the variability in vessel structures and the marginal distinction between arteries and veins poses challenges to accurate A/V classification. This paper proposes a novel Multi-task Segmentation and Classification Network (MSC-Net) that utilizes the vessel features extracted by a specific module to improve A/V classification and alleviate the aforementioned limitations. The proposed method introduces three modules to enhance the performance of A/V classification: a Multi-scale Vessel Extraction (MVE) module, which distinguishes between vessel pixels and background using semantics of vessels, a Multi-structure A/V Extraction (MAE) module that classifies arteries and veins by combining the original image with the vessel features produced by the MVE module, and a Multi-source Feature Integration (MFI) module that merges the outputs from the former two modules to obtain the final A/V classification results. Extensive empirical experiments verify the high performance of the proposed MSC-Net for retinal A/V classification over state-of-the-art methods on several public datasets. [ABSTRACT FROM AUTHOR]

The poor convergence of surface mechanical responses of asphalt pavement has always been an important factor affecting the application of elastic system mechanics. This paper briefly reviewed the analytical solutions of the elastic multilayered system under an elliptical load. Then, the calculation efficiency of mechanical response at the surface was analyzed. Afterward, the integral kernel oscillation of mechanical response was analyzed. And it shows that the reason for the poor calculating efficiency of surface mechanical response is that Bessel function is difficult to converge. Finally, a fast calculation method was proposed through the piecewise calculation of integral and the simple formula of integral with Bessel function. The accuracy and efficiency of the proposed method was evaluated with comparing the initial calculation program. The result shows that the proposed method could greatly improve the efficiency of calculation and control the error within 1%. [ABSTRACT FROM AUTHOR]

Fundus segmentation is an important step in the diagnosis of ophthalmic diseases, especially glaucoma. A modified particle swarm optimization algorithm for optic disc segmentation is proposed, considering the fact that the current public fundus datasets do not have enough images and are unevenly distributed. The particle swarm optimization algorithm has been proved to be a good tool to deal with various extreme value problems, which requires little data and does not require pre-training. In this paper, the segmentation problem is converted to a set of extreme value problems. The scheme performs data preprocessing based on the features of the fundus map, reduces noise on the picture, and simplifies the search space for particles. The search space is divided into multiple sub-search spaces according to the number of subgroups, and the particles inside the subgroups search for the optimal solution in their respective sub-search spaces. The gradient values are used to calculate the fitness of particles and contours. The entire group is divided into some subgroups. Every particle flies in their exploration for the best solution. During the iteration, particles are not only influenced by local and global optimal solutions but also additionally attracted by particles between adjacent subgroups. By collaboration and information sharing, the particles are capable of obtaining accurate disc segmentation. This method has been tested with the Drishti-GS and RIM-ONE V3 dataset. Compared to several state-of-the-art methods, the proposed method substantially improves the optic disc segmentation results on the tested datasets, which demonstrates the superiority of the proposed work. [ABSTRACT FROM AUTHOR]

This paper studies the influence of geometric structure cutting on transverse crack treatment with the discrete elements method (DEM). Suitable strategies for geometrical structure cutting are put forward. The two-dimensional DEM model of asphalt mixture was established firstly. The asphalt mixture was simplified into a combination of voids, coarse aggregates, and asphalt mortar. The microscopic parameters of asphalt mixture were obtained by laboratory tests of asphalt mortar and mixture. The reliability of the modelling method and the microscopic parameters was verified by the DEM simulation of the laboratory tests of the asphalt mixture. Then, the mechanical response of transverse cracks treatment in different geometrical structures under wheel load and temperature load was analysed based on the orthogonal design method. This work concludes that a quadrangular groove with a depth of no less than 6 cm and a width of 60 cm is recommended for treatment of severe transverse cracks. The depth and width of the groove should be increased proportionally in zones where the traffic is higher or the temperature range is larger, but the breadth to width ratio should be less than 15. [ABSTRACT FROM AUTHOR]

Resin asphalt is widely used to improve the durability and thermal stability of asphalt concrete in recent years. In order to reduce the dependence of using petroleum asphalt in resin asphalt, the bio-oil, as a kind of by-product of cooking oil industry, was explored as the substitution of petroleum asphalt in resin asphalt materials in this study. The quantum chemical method was firstly utilised to characterise the curing mechanism of resin bio-oil. Then the reasonable preparation process of resin bio-oil was discussed based on the quantum chemical simulation results. Finally, the optimisation production method, which was named two-step method, was proposed. Based on the proposed simulation results, the resin bio-oil was also prepared in laboratory, followed by the road performance verification. The experimental results show that the produced resin bio-oil has excellent high and low temperature performance, when compares to neat and modified asphalt binders. The application of bio-oil as a substitute of petroleum asphalt in resin asphalt material could help to produce a greener and more sustainable infrastructure material. [ABSTRACT FROM AUTHOR]

Foamed asphalt cold-recycled mixtures have been increasingly used in China. However, the interlayer shear performance between the foamed asphalt cold-recycled layer and its top and bottom layers is still not clear. In this study, we explored factors affecting the interlayer shear performance of foamed asphalt cold-recycled layers (FACRL). Regarding the interlayer performance between the foamed asphalt cold-recycled layer and cement-treated base (CTB), the optimal content of the prime coat asphalt was 0.8 kg/m2 , and the prime coat asphalt was recommended to be applied on the surface of the base as soon as the base was paved. Styrene-butadiene-styrene (SBS)-rubber modified asphalt with a content of 2.3 kg/m2 and aggregates with a size range of 4.74–9.5 mm was recommended for use in the seal coats. The aggregates used in the seal coat were recommended to be premixed with a 0.3% asphalt binder to improve the adhesion and to be paved with a spreading area of 65%. Regarding the interlayer performance between the foamed asphalt cold-recycled layer and top hot-mix asphalt (HMA), the interlayer shear strength and fracture energy increased and then decreased with the added tack coat asphalt. The shear strength and fracture energy of the interlayer at 50°C was only 20% and 8% of that at 25°C, respectively. The optimum usage percent of the tack coat binder is 0.4 kg/m2. [ABSTRACT FROM AUTHOR]

To improve the availability of reclaimed asphalt pavement (RAP) in recycled hot mix asphalt (HMA), this study is focused on the mechanical performance of recycled HMA, which is beneficial for environmental conservation and consistent with the concept of sustainability. To alleviate the heterogeneity of the material composition of recycled HMA and enhance the usability and applicability of research means, micromechanical modeling is used to examine the modulus of recycled HMA, which is a critical parameter for asphalt pavement analysis. In this investigation, a four-layer built-in micromechanical model was constructed and derived to characterize recycled HMA. The micromechanical model indicated that the modulus of recycled asphalt was the main factor influencing the modulus of recycled HMA. Thus, the following study took the modulus of recycled asphalt as the main study subject. The frequency sweep test and three-point flexure beam test for recycled asphalt were designed and conducted to clarify the change trend of influence factors and further verify the reasonability and feasibility of the micromechanical model. Considering the diffusion behavior of the rejuvenator, the change trends of the factors are explored. The curing time apparently influences the modulus of recycled asphalt, followed by the curing temperature and the rejuvenator proportion. Finally, analytical results from micromechanical model matched well with the experimental results. The results of this study may be valuable for predicting the dynamic moduli of recycled HMA. • A four-layer built-in micromechanical model for recycled HMA is derived and validated. • The modulus of recycled asphalt prominently affects the modulus of recycled HMA. • The diffusion behavior of rejuvenators is considered in modulus research. [ABSTRACT FROM AUTHOR]

Damage to flexible pavements is known to be greatly influenced by climatic factors. Among them, partial thawing conditions encountered during winter warming periods, as well as in the early period of spring thaw, are reported as critical conditions for flexible pavement structures in cold regions. Experimental research was conducted using a laboratory test pit and a heavy vehicle simulator in order to document flexible pavement response during these critical conditions. Freezing of a typical experimental pavement was induced at −10°C. Thawing at 20°C was initiated afterwards from the surface downward. Pavement response and conditions were monitored using a thermistor string, as well as stress and strain sensors in all the pavement layers. The pavement response was measured regularly throughout thawing. It was more specifically documented for asphalt concrete temperatures of 10°C, 0°C, and −5°C when thaw depths reached 300, 600, 900, and 1,200 mm. The paper documents the pavement response for various partial thaw and temperature conditions. Weakening was found to be moderate in the pavement structural layers but reached a maximum for the subgrade soil once the pavement was completely thawed. [ABSTRACT FROM AUTHOR]

During the design of pavement structures, determining a reasonable thickness for pavement layers is critical. When an expressway is to be built in an area with a poor soil foundation, a reasonable subgrade treatment will make the pavement more durable. However, determining the optimal thickness of subgrade treatment is a difficult task for designers. A thicker treatment means a huge cost increase for the project, whereas a thinner treatment cannot achieve significant improvement in the mechanical behavior of pavement structures. This study used the finite-element method to analyze the mechanical response of real field pavement with subgrade treatments at certain depths. The study used an orthogonal design and gray relational theory to analyze the design indicators and make a better design for the pavement structure of a field expressway. The numerical calculation index and theoretical analysis results show that the treatment depth of subgrade soil has a significant influence on the stresses in an asphalt pavement structure and the bottom tensile strains of the asphalt layers. Therefore, designing a pavement structure with equal structural strength, using a reasonable depth for the cement-treated subgrade, instead of increasing the asphalt layer's thickness, is a more cost-effective solution. [ABSTRACT FROM AUTHOR]

With continuous economic and technological growth, sustainable development must be pursued and comprehensive transformation of economic and social development systems must promoted to allow humans and nature to coexist harmoniously. The use of renewable energy to replace traditional fossil materials in road engineering can reduce carbon emissions and serve as an environmentally friendly approach. Bioasphalt production and the use of biological rejuvenators in road areas have attracted research attention. Existing studies show that biological rejuvenators can effectively improve the regeneration efficiency of reclaimed asphalt pavement (RAP). Different biological rejuvenators have different mechanisms for RAP recovery, which determine the recovery efficiency of RAP. Based on an analysis and summarization of the application of different types of rejuvenators, we provide a comprehensive review of the current studies on biological rejuvenators applied to roads, including the mechanisms, performance, and challenges associated with rejuvenators from different biological sources. Additionally, we discuss the potential for using microorganisms as asphalt rejuvenators. This review shows that plant-sourced rejuvenators can supplement the missing light components in aging asphalt at the colloidal structural level via diffusion and fusion to restore the original asphalt properties. Animal- and algal-sourced rejuvenators can depolymerize the associations formed by van der Waals forces, hydrogen bonds, charge transfer, and π-π interactions among aromatic lamellae in aged asphalt through intermolecular interactions. Microorganisms can crack polycyclic aromatic hydrocarbons (PAHs) at the molecular level and have potential as asphalt rejuvenators. This review provides a reference for the future application of biological rejuvenators from different sources to road engineering. [Display omitted] • The biomass rejuvenators which can be used to restore the aged asphalt were classified. • The mechanism of biological rejuvenators from different sources was summarized and analyzed. • The properties and research status of biological rejuvenators from different sources were comprehensively discussed. • The challenges and limitations of biological rejuvenators from different sources were discussed. • The potential application of biological rejuvenators in asphalt materials is prospected and guided. [ABSTRACT FROM AUTHOR]

• The physical and mechanical behaviors of corn stalk fiber modified asphalt binder were studied. • The addition of corn stalk fiber will increase the high temperature performance of asphalt. • Corn stalk fiber can improve the temperature sensitivity of asphalt binder. The properties of asphalt binder modified with corn stalk fiber were investigated in this study. The physical-mechanical behaviors of the fiber modified asphalt binder were studied by the penetration and softening point tests, dynamic shear test, bending beam rheometer test and rotational viscosity test. The results indicate that the addition of corn stalk fiber decreases the penetration and increases the softening point of the asphalt binder. Furthermore, the addition of the corn stalk fiber increases the complex modulus and decreases the phase angle of the asphalt. The creep stiffness of the asphalt binder at low temperatures first decreases and then increases with an increase in corn stalk fiber content. The variation of the m-value of the asphalt binder is the opposite to which of the creep stiffness. The corn stalk fiber has good uniformity in the asphalt binder, followed by basalt fiber and finally lignin fiber. The viscosity results indicate that the addition of corn stalk fiber can increase the viscosity of the asphalt binder, and the temperature sensitivity of the asphalt binder decreases. [ABSTRACT FROM AUTHOR]

In recent years, the regeneration technology of aged asphalt in construction engineering has received much attention. The diffusion performance of the rejuvenator is a key factor in this kind of regeneration technology. But at present, the relevant research is still not mature. To forward this research, this study established molecular dynamic models of three diffusion systems with the open source large-scale atomic/molecular massively parallel simulator, including new asphalt, short-term aged asphalt and long-term aged asphalt. This study then analysed the diffusion mechanism and influence factors including temperature, ageing and the diffusion laws of different kinds of molecules. It was found that besides thermal motion, molecular force also greatly contributes to the diffusion of asphalt and rejuvenator. It was also found that micro voids in asphalt increase the contact area and promote the fusion of the rejuvenator and asphalt. Diffusion speed increases as temperature rises, and diffusion speed in aged asphalt is higher than that in new asphalt, especially at higher temperatures. The simulation results also suggest that small or catenarian molecules diffuse faster than the network structures. [ABSTRACT FROM AUTHOR]

Determining the influential factors of noise characteristics in dense-graded asphalt mixtures and field asphalt pavement is important in constructing highways that are both low noise and environmentally friendly. In this study, the effects of nominal maximum aggregate size, asphalt binder type, air void percentage, and the service life of pavement on the noise absorption characteristics of asphalt mixtures were first investigated in laboratory. Thereafter, tire/pavement noise measurements were conducted on different types of dense-graded asphalt pavements. The effects of the service lives of the pavements, the types of the pavements, driving speeds, and test temperatures on the noise levels of the pavements were also studied. The Zwicker method is used to calculate psychoacoustic parameters on the tire/pavement noise spectrum. The laboratory results indicate that reducing the nominal maximum aggregate size, using rubber asphalt, and increasing air void percentage as well as surface texture depth improve the sound absorption performance of asphalt mixtures. The field measurements show that laying down asphalt pavements with a shorter service life or larger texture depth, using rubber asphalt, reducing traffic speed, and increasing air temperature can reduce noise. [ABSTRACT FROM AUTHOR]

The warm-mix technology and high reclaimed asphalt pavement (RAP) contents applied in asphalt mixture can effectively reduce the use of energy resources and waste materials disposal. To realize the performance requirement of warm-mix recycled asphalt mixture, it is significant to develop specific warm-mix rejuvenators with satisfactory performance. Diffusion and crack-resistance properties are the key factors combined with engineering characteristics for rejuvenator design. In this research, a new type of asphalt rejuvenator for warm-mix recycled asphalt mixture with high RAP contents was designed. Then, the molecular properties of the key ingredients were explored according to asphalt aging theory and molecular diffusion simulation results. The results indicate that the diffusion group should contain linear alkanes or small alkanes, aromatics with a low aromaticity, or molecules with weak or no polar groups and low cohesive energy. Rejuvenators and corresponding mixture were then prepared, followed by performance testing. The results show that the strength of the recycled mixture increased during rejuvenator diffusion, and polymer addition to certain rejuvenators effectively improved the interface performance of the asphalt fusion layer. The fine aggregate mortar beam test results showed that this approach represents a simplified test method to evaluate the low-temperature performance of rejuvenators. The overall performance of the designed rejuvenator is satisfactory and fully meets the requirement of the surface layer of provincial highways in most areas of China. The application of this technology has good environmental and economic benefits. [Display omitted] [ABSTRACT FROM AUTHOR]

• States of sulfur in bitumen were different with sulfur dosage and curing time. • Chemical cross-linked sulfur and recrystallized sulfur harden the bitumen. • Curing time of 15 days for sulfur extended bitumen is proper. Partial substitution of sulfur for bitumen helps reduce bitumen consumption while promoting recycling of the sulfur in waste residues. The properties of sulfur-extended bitumen (SEB) are closely related to the chemical reaction process and the phase transition process of sulfur in bitumen, and these two processes are influenced by sulfur dosage and curing time. Therefore, SEB samples with sulfur dosages of 1 %, 5 %, 10 %, 15 %, 20 %, 25 % and 30 % were prepared and cured for 0, 15, 30, or 60 days. Differential scanning calorimetry was conducted to understand the sulfur recrystallization process in bitumen, and a dynamic shear rheometer was used to analyze the rheological properties of SEB samples. Results show that molten sulfur can turn to monoclinic sulfur immediately after cooling; the monoclinic sulfur gradually turns to orthorhombic sulfur, and the ratio between the two forms stabilizes after curing for 15 days. The recrystallization of sulfur in bitumen needs sufficient curing time, and the sulfur states in bitumen vary depending on the sulfur dosage. When the sulfur dosage is lower than 15 %, sulfur dissolves into bitumen. The dissolved sulfur softens the bitumen and increases its low-temperature properties and resistance to fatigue cracking. When the sulfur dosage is 10 %, 15 %, 20 %, 25 %, or 30 %, surplus sulfur is recrystallized to orthorhombic sulfur. When the sulfur dosage is 35 % or more (the dosages evaluated in the former study), surplus sulfur is recrystallized to monoclinic sulfur. The chemically crosslinked sulfur and recrystallization sulfur help increase the elastic component in bitumen and improve the rutting resistance and fatigue life of bitumen. However, when the sulfur dosage exceeds 20 %, the effect of stress concentration stands out due to bulk gathering of recrystallized sulfur, and this effect stops further improvement in the fatigue life of SEB samples. The effects of recrystallization sulfur on bitumen are mainly concentrated in the first 15 days of curing time, even though much more recrystallized sulfur is detected after more curing time, even at 60 days (the longest curing time evaluated in this study). Therefore, a curing time of 15 days is sufficient for accurate evaluation of SEB properties. [ABSTRACT FROM AUTHOR]

Thermal cracking is a widespread distress for asphalt pavement in cold regions. The main reason causing thermal cracking is due to the contraction of asphalt concrete. Once thermally induced contraction stress exceeds the fracture resistance of the asphalt concrete, cracks start to develop. Comparing to aggregate, asphalt mastic is believed to have much larger thermal coefficient of contraction, therefore play a more significant role in determining the thermal cracking resistance of asphalt pavement. To modify the inherent thermal property of asphalt mastic, a new-developed material, zirconium tungstate (ZT), was utilized in this study. Different from normal material’s heated expansion and cooled contraction properties, ZT has a negative thermal expansion property of heated contraction and cooled expansion. Being as a substitute for mineral filler, the physical properties of ZT fillers and performances of asphalt mastics made with ZT fillers were investigated. Results show that ZT can better absorb and adhere asphalt binder when comparing with mineral filler. The addition of ZT is able to decrease the thermal coefficients of volume contraction and creep stiffness, improve the adhesive bond between filler and asphalt binder and reduce the complex modulus of asphalt mastic. [ABSTRACT FROM AUTHOR]

[Display omitted] • Basalt fibers can improve the low temperature crack resistance of asphalt mixture. • The Weibull distribution can approximately describe the fiber distribution in basalt fiber asphalt mortar. • Better reinforcement can be achieved by well dispersed basalt fibers. • The spatial distribution of fibers truly influence the flexural tensile properties of asphalt mixture. This study aims to reveal the relationship between the uneven distribution characteristics of basalt fibers and the flexural tensile performance of asphalt mixture. Nano Computed Tomography(nano-CT) was used to explore the realistic distribution features of basalt fibers in asphalt mortar. In addition, the distribution fitting and goodness of fit tests were carried out to find out the distribution form that can well describe the distribution of basalt fibers. The three-dimensional fiber models with different distribution forms were established in finite element software ABAQUS. Then the three-point bending test was simulated to analyze the influence of fiber dispersion and distribution on the flexural tensile properties of the asphalt mixture. Simulation results show that the asphalt mixture beam model shows better tensile resistance when the fibers are better dispersed. Moreover, when more basalt fibers are at the bottom of the middle span, it is more conducive to reducing the peak stress at the bottom of the beam and delaying the cracking of the asphalt mixture. [ABSTRACT FROM AUTHOR]

The properties of asphalt binder modified by bio-oil derived from waste cooking oil were researched. Firstly, four components separation test and fourier transform infrared spectroscopy (FT-IR) test were carried out to investigate the chemical compositions of experimental materials. Then the physical and mechanical behaviors of bio-oil modified asphalt binders were studied by penetration grading tests, rotational viscosity (RV) test, separation tendency test, dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test. Four components separation test results indicate that bio-oil is mainly composed of aromatics, resins and saturates. Almost no chemical reactions between bio-oil and control asphalt are noticed through FT-IR test results. The addition of bio-oil decreases the softening point and viscosity, increases the penetration and ductility of control asphalt binder. Separation tendency test results demonstrate that bio-oil and control asphalt have good compatibility under static heated storage conditions. Furthermore, the addition of bio-oil decreases the complex modulus and creep stiffness, increases the phase angle and m-value of asphalt binder, which means that adding bio-oil could reduce the deformation resistance and elastic recovery performance of control asphalt, and improve the stress relaxation property and also helps to the improvement of thermal cracking resistance of control asphalt. [ABSTRACT FROM AUTHOR]

• The change mechanism of strength and viscosity of liquid asphalt is explained. • The time–temperature equivalence principle predicts the performance of liquid asphalt mixtures. • Reasonable suggestions for liquid mixtures construction in winter are proposed. This paper primarily analyzes the change in performance of liquid asphalt and its mixture in each stage and proposes suggestions for fabricating liquid asphalt mixtures in cold weather. The results of GPC and SEM can explain the reasons for the increase in viscosity and strength of liquid asphalt after curing. In addition, the generalized time–temperature equivalence principle is used to predict the performance changes of liquid asphalt, asphalt mortar, asphalt mastic and asphalt mixtures under different curing conditions. The results show that increasing the filler content improves the deformation resistance of liquid asphalt mixtures. The low-temperature performance of liquid asphalt mixtures is outstanding. During construction in cold weather, liquid asphalt or its mixtures can be used after curing at 60 ∼ 110 °C for 1 ∼ 10 h. These parameters can ensure the strength of cold mixed liquid asphalt mixtures in low-temperature environments, and roads repaired with this asphalt can be rapidly opened to traffic. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we propose a delayed chaotic neural network with annealing controlling strategies (DCNN-AC) to solve the NP-complete maximum clique problem (MCP). We point out some flaws in the variable delayed neural network proposed by Chen, and demonstrate that DCNN-AC is a powerful chaotic neural network through analyzing its single neural model and its “beautiful” chaotic dynamics. DCNN-AC has richer and more flexible chaotic dynamics and flexible annealing controlling strategies, so that it can be expected to have higher searching ability for globally optimal or near-optimal solutions. The DCNN-AC performance has been verified by simulations on some MCP benchmark instances. The comparisons with some famous proximate algorithms show the superiority of DCNN-AC in terms of the solution quality and the comparable computation time. [Copyright &y& Elsevier]

Highlights: [•] A viscoelastic–plastic damage model is developed for porous asphalt mixtures. [•] Loss of cohesion leads to failure of porous asphalt under freeze–thaw cycles. [•] The damage of porous asphalt mixtures is affected by temperature and loading rate. [ABSTRACT FROM AUTHOR]

Recently, electrically heated cable has been used to melt snow and ice from roads around the world. To increase the heat transfer efficiency of asphalt pavement and improve its snow and ice removal ability, but decrease summer solar heating, which could cause rutting, a new asphalt pavement system with various thermal conductivity for layered structures was proposed. This pavement system includes a bottom high-conductivity layer and a top low-conductivity layer. The heat transfer of this pavement system was simulated with the finite element method and tested in a real environment. The results show that a structural combination of a top low-conductivity layer and a bottom high-conductivity layer could be helpful in increasing the surface temperature of pavement during the bottom heating at winter, but decreasing the inner temperature of pavement subjected to summer solar radiation, therefore reducing its rutting potential at summer. • A new asphalt pavement system with various thermal conductivity was proposed. • Graphite and diatomite were selected as the high and low thermal conductivity materials. • The heat transfer of this pavement system was simulated with the finite element method. • A structural combination with high and low-conductivity layer can help to increase the surface temperature. [ABSTRACT FROM AUTHOR]

Industry waste materials are commonly used in road engineering. In this study, crushed ceramic waste aggregates (CWAs) were utilized and added into asphalt mixtures to investigate their potential usage. A finite-element method (FEM) was employed first to examine the effect of material thermal conductivity on the temperature gradient of pavement structure. A significant effect of the surface layer's conductivity in asphalt pavement on the temperatures (at the top and bottom positions of the middle layer) was found in model simulation. Next, the mix design for asphalt mixtures with different percentages of CWAs was developed, and their thermal properties were tested. It is concluded that asphalt mixtures with a reasonable substitution percentage of CWA can satisfy pavement performance requirements. The addition of CWAs can reduce the thermal conductivity of asphalt mixtures, which is proven helpful in reducing the temperature gradient of pavement. Finally, it is recommended that less than 40% CWA be added into asphalt mixtures to replace natural coarse aggregates considering its effect on the performance of mixtures. [ABSTRACT FROM AUTHOR]

Based on chaotic neural network, a multiple chaotic neural network algorithm combining two different chaotic dynamics sources in each neuron is proposed. With the effect of self-feedback connection and non-linear delay connection weight, the new algorithm can contain more powerful chaotic dynamics to search the solution domain globally in the beginning searching period. By analyzing the dynamic characteristic and the influence of cooling schedule in simulated annealing, a flexible parameter tuning strategy being able to promote chaotic dynamics convergence quickly is introduced into our algorithm. We show the effectiveness of the new algorithm in two difficult combinatorial optimization problems, i.e., a traveling salesman problem and a maximum clique problem. [ABSTRACT FROM AUTHOR]

Abstract: The impact of salt on asphalt binders was first studied through basal experiments of binders. The complex influence of freeze–thaw cycles and salt on strength, volume and weight of three types of asphalt mixtures was then investigated through freeze–thaw tests. Test results indicate that salt has a significant effect on the low temperature performance of asphalt binders; Freeze–thaw is a main influencing factor when the percentage of salt is less than 3%, and the erosion effect of salt accelerates the failure of asphalt mixtures when the percentage of salt is more than 3%. The damage of asphalt mixtures is initiated by ice expansion load and accelerated by the interfacial damage between asphalt and aggregate or fracture of asphalt mortar. It can therefore be concluded that different types of asphalt mixtures have fixed residual lives after a number of freeze–thaw cycles. Freeze–thaw cycles, salinity, percent air void, asphalt property and 4.75mm percent passing are main factors having an influence on freeze–thaw strength. [Copyright &y& Elsevier]

Abstract: In this article, we propose a new elastic net method to solve the traveling salesman problem by introducing some time-dependent parameters. This method can help network neurons move quickly near to the cities at early stage, and gradually increase the strength that pulls neurons towards their neighbours on the path to minimize the total path length. This enables the network to have superior ability of searching for cities, and converge sooner to a saturated state. Simulation results illustrate that the proposed network performs better than the classical elastic net for optimization both in solution quality and convergence speed. [Copyright &y& Elsevier]

Abstract: In this paper, coefficient sensitiveness of transiently chaotic neural network (TCNN) for maximum clique problem (MCP) is analyzed. By introducing a new definition of adaptivity into TCNN and utilizing a neuron filter, the domain of coefficient selection is enlarged to search globally optimal solution and near-optimal solution on MCP. Based on our analysis on the characteristic of TCNN, we propose a TCNN filter algorithm to shrink the network scale and improve solution quality. The algorithm effectively relaxes the coefficient sensitiveness and improves network ability to solve MCP. Simulations have been performed to verify the validity of our algorithm. [Copyright &y& Elsevier]

• A kind of epoxy asphalt with excellent properties was produced. • Ceramsite was used to replace 30–50% of stone in the wear layer. • The wear layer can accelerate the ice melting. • The antiskid performance of pavement can be improved with wear layer application. A design method for an anti-ice and antiskid wear layer on pavement is presented in this paper. A kind of bonding material with excellent properties has been developed that can maintain a good bonding ability in high and low temperature environments and has good UV aging resistance. Porous high-strength shale aggregates are used to replace portions of stone, and the functional characteristics of the ice inhibition of the wear layer are realized by soaking in saturated salt water. The results show that after adding ceramsite, the freezing point of pavement can be reduced by approximately 5 °C at most and the ice melting rate can be increased by approximately 30%. After continuous soaking for ten days, salt can still be precipitated from the aggregate, which can inhibit the formation of an ice film to a certain extent. As the proportion of ceramsite increases, the polishing resistance of the pavement increases. Under conditions of flooding and freezing, the BPN of the aggregate mixed with ceramsite is approximately 50% higher than that of andesite aggregate. The wear layer can provide a good anti-ice and antiskid performance, which is helpful for traffic safety under wintry conditions. [ABSTRACT FROM AUTHOR]

Hole-edge crack quantification of bolt joints is critical for monitoring and estimating structural integrity of aircraft. The paper proposes a new triangle eddy current sensor array for the purpose of increasing the level of quantifying hole-edge crack parameters, especially, the crack angle. The new senor array consists of triangular coils instead of planar rectangular coils. The configuration of the novel sensor array, including the excitation current directions and the excitation winding shape, is optimized by simulation. The ability of the proposed sensing film to identify the crack parameters has been verified by finite element simulations and experiments. Results shows that triangular coils with same current directions in circumferentially adjacent coils and opposite current directions in axially adjacent coils achieve better performance in sensor linearity and resolution compared to rectangular coils. In addition, it has also been proved that the sensing film has a good potential to identify the crack depth and length. [ABSTRACT FROM AUTHOR]

• The molecular model of foamed asphalt cold-recycled mixture was presented. • Moisture reduce the bonding strength among the components of mixtures. • Bonding between RAP and new asphalt is greater than that between RAP and cement. The recycling and reuse of asphalt pavement have become requirements for environmental protection. Foamed asphalt cold-recycling technology is drawing extensive attention and being widely applied. Foamed asphalt cold recycled mixture has advantages such as energy savings, reduced asphalt content, and low transportation costs, and it has the characteristics of both rigid and flexible pavement. However, foamed asphalt mixtures are complex in composition, as it includes recycled asphalt pavement (RAP), water, new asphalt, aggregate, and cement. Therefore, the interaction mechanisms between recycled asphalt pavement and cement or foamed asphalt within the presence of water in the mixing, curing and service procedures will play a key role in determining the development and deterioration of strength of foamed asphalt cold recycled mixture, which was however not well clarified. This study firstly specified the decrease of strength of foamed asphalt cold recycled mixture when considering the effect of water in field project. It was found that the strength of foamed asphalt cold recycled mixture increased along with the decrease of water content during the curing procedure, and decreased by 15–20% through the winter frost. Then the interaction between RAP and cement or foamed asphalt within and without the presence of water had been analyzed with molecular simulation method. The mechanisms of strength development and deterioration of foamed asphalt cold recycled mixture were clarified from the point of view of molecular interaction. The simulation results indicate that the adhesion strength between RAP and cement is greater than that between RAP and new asphalt. The presence of water simultaneously weakens the adhesive bond strengths between RAP and cement and RAP and asphalt. [ABSTRACT FROM AUTHOR]

SBS (styrene-butadiene-styrene block copolymer) is a thermoplastic elastomer with properties most similar to rubber. SBS asphalt modifier is mainly composed of a styrene-butadiene-styrene block copolymer with a certain amount of additives and stabilizers. SBS-modified asphalt binder has always been the most commonly used pavement material both domestically and internationally. However, conventional wet-process SBS-modified asphalt binder requires manufacturers to produce it in advance and transport it to a mixing plant for blending. This has provided an opportunity for unscrupulous businesses to reduce the amount of SBS by adding other substances, allowing inferior asphalt binder to pass inspections undetected. At the same time, conventional wet-process SBS-modified asphalt tends to undergo phase separation and experience a decline in performance as the storage time increases. However, dry-process SBS-modified asphalt can be directly added at the mixing plant, effectively addressing the issues associated with conventional wet-process SBS-modified asphalt. It also helps to reduce environmental pollution to a certain extent. This study investigates the extraction process of dry-process SBS-modified asphalt binder. It clarifies the performance and modification mechanisms of two types of dry-process SBS-modified asphalt binder at different dosages through various testing methods, including basic indicators, rheological properties, infrared spectroscopy, and fluorescence microscopy. The results indicate that due to the incorporation of oil, crosslinker, solubilizer, and other substances into dry-process SBS modifier, there is a small amount of chemical reaction with asphalt in the melting process. The high- and low-temperature properties and fatigue properties of the two dry-process SBS-modified asphalt binders at a 7% dosage are close to wet SBS-modified asphalt binder at a 5% dosage. [ABSTRACT FROM AUTHOR]

Serious environmental pollution will occur if corn stalk materials are discarded randomly or burned in open air. This study presents a possible method for using corn stalk materials to make fibers used in stone matrix asphalt (SMA) mixtures to address this problem. To obtain an in-depth understanding of the application of corn stalk fibers in SMA mixtures, basic properties such as high-temperature, low-temperature, moisture susceptibility, and fatigue performance, and the dynamic modulus were researched. The performances of SMA mixtures with lignin fibers and basalt fibers were studied as comparative research. Corn stalk fibers and basalt fibers, used as composite fibers, were incorporated jointly into the SMA mixtures, and the performance was evaluated. The test results showed that the high-temperature, low-temperature, and moisture susceptibility performance of SMA mixtures with corn stalk fibers can meet the specification requirements. The addition of corn stalk fibers and basalt fibers in SMA mixtures improved the high-temperature, low-temperature, and fatigue performance of SMA mixtures and had comparable dynamic moduli. A content of 0.6% corn stalk fibers is recommended for SMA mixtures. For the application of composite fibers, contents of 0.4% corn stalk fibers and 0.2% basalt fibers currently are recommended for SMA mixtures. In general, corn stalk fibers can be used in asphalt pavement, and the application of corn stalk fibers can reduce construction costs and environmental pollution. [ABSTRACT FROM AUTHOR]

Lamb wave-based damage detection for large-scale composites is one of the most prosperous structural health monitoring technologies for aircraft structures. However, the temperature has a significant effect on the amplitude and phase of the Lamb wave signal so that temperature compensation is always the focus problem. Especially, it is difficult to identify the damage in the aircraft structures when the temperature is not uniform. In this paper, a compensation method for Lamb wave-based damage detection within a non-uniform temperature field is proposed. Hilbert transform and Levenberg-Marquardt optimization algorithm are developed to extract the amplitude and phase variation caused by the change of temperature, which is used to establish a data-driven model for reconstructing the reference signal at a certain temperature. In the temperature compensation process, the current Lamb wave signal of each exciting-sensing path under the estimated structural condition is substituted into the data-driven model to identify an interpolated initial temperature field, which is further processed by an outlier removing algorithm to eliminate the effect of damage and get the actual non-uniform temperature field. Temperature compensation can be achieved by reconstructing the reference signals within the identified non-uniform temperature field, which are used to compare with the current acquired signals for damage imaging. Both simulation and experiment were conducted to verify the feasibility and effectiveness of the proposed non-uniform temperature field identification and compensation technique for Lamb wave-based structural health monitoring. [ABSTRACT FROM AUTHOR]

Highlights • The mathematical models, Prony series and power law, of four types asphalt mixture were investigated. • Two numerical integration methods were used to convert the relaxation modulus of asphalt mixture form creep compliance. • The formula for calculating relaxation modulus in Laplace domain was proposed. • The Laplace transform method was implemented to calculate the relaxation modulus from Laplace domain to time domain. Abstract The relaxation modulus of an asphalt mixture is adopted for evaluation of pavement structural soundness. However, it is difficult to perform a strain-controlled relaxation test on an asphalt mixture to obtain the relaxation modulus. The aim of this paper is to obtain the relaxation modulus expression in the Laplace transform domain and then perform a Laplace transform to derive the relaxation modulus from creep compliance. A uniaxial static creep test was conducted on four types of asphalt mixtures at 20 °C, 30 °C, and 40 °C and under a load of 0.3 MPa. The Prony series and power law were used to model creep compliance with good fitting of R 2 > 0.95. Because the Laplace transform of the power law was a gamma function, the Prony series was used to simulate creep compliance and then applied to interconverting the viscoelastic functions. The Simpson and Gauss methods were used to convert the relaxation modulus from creep compliance based on a convolution formula and the calculation results from the two methods were shown to be equivalent. Based on the Laplace transform formula for creep compliance and the relaxation modulus, an equation for calculating the relaxation modulus in the Laplace domain was proposed. Numerical inversion of the Laplace transform, using the fixed Talbot method, was implemented to compute the relaxation modulus in the time domain and the results were compared with those derived by using the Gauss method. The average error is less than 10−4 and the computational speed of the fixed Talbot method is a factor of 25 faster than that of the Gauss method, demonstrating the high precision and high efficiency of the Laplace transform method for computing the relaxation modulus. The method developed in this study provides an effective tool for interconverting viscoelastic functions of asphalt mixtures. [ABSTRACT FROM AUTHOR]

The existing research on pavement mechanics was rarely conducted from the perspective of the spatial stress state. In this research, by utilizing analytical solutions, a three-dimensional space calculation program for asphalt pavement was developed to study the spatial distributions of the stress state and damage risk of the pavement structure. First, this study selected various types of pavement structures to analyze the spatial distribution of the stress state. The results indicated that the important influence factors are the order and quantity of asphalt-bound material, chemically stabilized material, and granular material in the structure. In contrast, the thicknesses of these materials have a limited effect. Then, the stress states of the asphalt pavements in winter and summer were compared. The results demonstrated that the tensile region bulges upward at low temperatures, and the structure is more inclined to experience tension and compression simultaneously. In addition, the failure criterion suitable for asphalt mixture materials was applied, and a strength conversion coefficient between different temperatures was proposed to calculate the damage situations of asphalt mixture layers. Three-dimensional images were generated to display the differences in the dangerous positions and damage forms for different structural types and temperature conditions. [ABSTRACT FROM AUTHOR]

Deep learning (DL) has achieved breakthrough successes in various tasks, owing to its layer-by-layer information processing and sufficient model complexity. However, DL suffers from the issues of both redundant model complexity and low interpretability, which are mainly because of its oversimplified basic McCulloch–Pitts neuron unit. A widely recognized biologically plausible dendritic neuron model (DNM) has demonstrated its effectiveness in alleviating the aforementioned issues, but it can only solve binary classification tasks, which significantly limits its applicability. In this study, a novel extended network based on the dendritic structure is innovatively proposed, thereby enabling it to solve multiple-class classification problems. Also, for the first time, an efficient error-back-propagation learning algorithm is derived. In the extensive experimental results, the effectiveness and superiority of the proposed method in comparison with other nine state-of-the-art classifiers on ten datasets are demonstrated, including a real-world quality of web service application. The experimental results suggest that the proposed learning algorithm is competent and reliable in terms of classification performance and stability and has a notable advantage in small-scale disequilibrium data. Additionally, aspects of network structure constrained by scale are examined. [ABSTRACT FROM AUTHOR]

Most countries adopt the mechanical theory of a layered elastic system under vertical load as the design method for asphalt pavement. This calculation theory does not consider the influence of the horizontal force of the vehicle load, and it is also unable to calculate the creep, relaxation, and other behaviors of the pavement material under repeated loads. To overcome these limitations, this research derived the analytical solution of the layered viscoelastic system under horizontal and vertical loads and developed a numerical calculation program for viscoelastic half-space and multilayer system. The accuracy, efficiency, and stability of the calculation program were tested to meet the requirements. The viscoelastic mechanical responses of the checkpoints in structural design under different horizontal load factors were calculated through the program. The results showed that the horizontal load significantly affects the distribution of stress and displacement of the pavement structure and the extent of the horizontal load impact varies in different positions. The horizontal load should be considered in pavement mechanics analysis and structural design. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we analyze the formula of weights definition in the discrete competitive Hopfield network (DCHOM) and point out its flaw when using it to solve some special instances of maximum clique problem (MCP). Based on the analysis, we propose an improved competitive Hopfield network algorithm (ICHN). In ICHN, we introduce a flexible weight definition method which excites the competitive dynamics, and we also present an initial values setting strategy which efficiently increases the probability of finding optimal solutions. Furthermore, an inhibitive competitive activation mechanism is introduced to form a new input updating rule which reduces significantly the number of neurons with an intermediate level of activations. Our algorithm effectively overcomes the flaw of the DCHOM, and exhibits powerful solving ability for the MCP. Experiments on the benchmark problems and practical applications verify the validity of our algorithm. [Copyright &y& Elsevier]

Currently, the utilization rate of fine reclaimed asphalt pavement (FRAP) in hot recycled asphalt mixtures is low. Therefore, this study focuses on the development and performance optimization of recycled gussasphalt (RGA) with a FRAP content of 38.5%. The total content of reclaimed asphalt pavement (RAP) is 50%. The impact of various factors on the pavement performance of RGA, including modifier dosage, asphalt content, type of asphalt, rejuvenating agent, mixing time, and RAP preheating temperature was analyzed. The results show that RGA has good workability and fatigue resistance. Its high- and low-temperature performance meets the requirements of the Chinese specification for gussasphalt, but it is still slightly inferior to gussasphalt made from virgin materials. Increasing the preheating temperature of RAP and extending the mixing time of RGA can enhance the performance of RGA. But excessive increases will cause asphalt aging, which negatively affects RGA's low-temperature performance and fluidity. More attention should be given to improving the low-temperature performance of RGA, which can be improved by selecting asphalt with better resistance to aging or by incorporating a rejuvenating agent. RGA offers significant economic benefits, with a cost reduction of approximately 27% compared to GA. • Recycled gussasphalt (RGA) containing 50% RAP was developed. • This RGA exhibits satisfactory workability, fatigue resistance, and economic benefits. • Choosing suitable asphalt or reinforcing modifiers is important for improving the high-temperature performance of RGA. • The impact of mixing time and preheating temperature of RAP on the performance of RGA was investigated. • Adding rejuvenating agents is the optimal strategy to improve the low-temperature performance of RGA. [ABSTRACT FROM AUTHOR]

In this study, a hybrid metaheuristic algorithm chaotic gradient-based optimizer (CGBO) is proposed. The gradient-based optimizer (GBO) is a novel metaheuristic inspired by Newton's method which has two search strategies to ensure excellent performance. One is the gradient search rule (GSR), and the other is local escaping operation (LEO). GSR utilizes the gradient method to enhance ability of exploitation and convergence rate, and LEO employs random operators to escape the local optima. It is verified that gradient-based metaheuristic algorithms have obvious shortcomings in exploration. Meanwhile, chaotic local search (CLS) is an efficient search strategy with randomicity and ergodicity, which is usually used to improve global optimization algorithms. Accordingly, we incorporate GBO with CLS to strengthen the ability of exploration and keep high-level population diversity for original GBO. In this study, CGBO is tested with over 30 CEC2017 benchmark functions and a parameter optimization problem of the dendritic neuron model (DNM). Experimental results indicate that CGBO performs better than other state-of-the-art algorithms in terms of effectiveness and robustness. [ABSTRACT FROM AUTHOR]

• A high performance pavement material was produced with resin bio-oil and aggregates. • The temperature sensitivity of resin bio-oil mixtures is fairly low. • The resin bio-oil mixtures have good rutting and thermal cracking resistance. In recent years, resin asphalt and bio-oil have been widely used to improve various properties of asphalt concrete. The road performance of homemade resin bio-oil able to completely replace petroleum asphalt was explored in this study. The homemade resin bio-oil, 90# neat asphalt, and SBS-modified asphalt were used to perform the Marshall test to determine the mix ratio and optimal binder content. Then, the three kinds of mixtures were tested for dynamic modulus, flow test, and semicircular bend tests to explore their road performance. The experimental results show that the homemade resin bio-oil mixture has better resistance to deformation at high temperature and incomparable crack resistance under extremely low temperature conditions compared with the other two kinds of petroleum asphalt mixtures. [ABSTRACT FROM AUTHOR]

The quality of the waterproof adhesive layer significantly impacted the safety and service life of concrete bridge deck pavements. Therefore, this study focused on the preparation of the waterborne epoxy resin-polyurethane-emulsified asphalt (WEPEA) and investigated the factors influencing its road performance. The component proportions of WEPEA were determined based on tensile strength and elongation at break, while its physical and chemical properties were systematically studied. Indoor tests were conducted to investigate the impact of environmental factors and surface treatment processes on WEPEA's road performance. The research findings indicated that the optimal proportions for WEPEA were 30% waterborne epoxy resin (WER) and 8% waterborne polyurethane (WPU). WEPEA exhibited excellent bonding performance, low-temperature flexibility, adhesion, waterproof properties, and corrosion resistance. Surface contaminants, freeze-thaw cycles, and immersion in water reduced the road performance of WEPEA. Surface treatments such as surface brushing, surface grooving, and surface milling enhanced WEPEA's road performance, with surface grooving being the most effective method. According to value engineering theory, compared to other waterproof adhesive materials, WEPEA had better economic benefits as a waterproof adhesive material. • WER and WPU improved the strength and flexibility of WEPEA. • Environmental factors reduced the road performance of WEPEA. • The surface treatment process improved the road performance of WEPEA. • As a waterproof adhesive material, WEPEA demonstrated superior cost-effectiveness. [ABSTRACT FROM AUTHOR]

This study focused on developing a high-toughness composite-modified asphalt (CMA), to enhance the performance of rich bottom layer mixes and its crack resistance. The content of crumb rubber (CR), epoxy resin (ER), and polyaryl polymethylene isocyanate (PMDI) were chosen as design parameters. Response surface methodology (RSM) was employed to develop models for creep strength (S), fatigue performance parameter (N f), yield energy (YE), and Brookfield viscosity (BV) of CMA. Then, these models were used to optimize the content of modifiers. Additionally, rich bottom layer mixes were designed using SBS-modified asphalt (SMA) and the newly developed CMA as binders, and their performances were evaluated. The results demonstrated the accuracy and predictive ability of the RSM models. The composite-modified asphalt mixes (CMAM) showed superior road performance and crack resistance compared to SBS-modified asphalt mixes (SMAM). Importantly, CMAM aligned effectively with the functional requirements of the rich bottom layer. This research contributes novel materials and methods for enhancing pavement crack resistance, providing valuable insights for improving the durability and longevity of pavements. • The content of modifiers in the composite-modified asphalt was optimized based on response surface methodology. • Rich bottom layers mixes were designed and evaluated for performance. • The crack resistance of both rich bottom layers mixes is explored. [ABSTRACT FROM AUTHOR]

• A 2D DEM model of cement-treated base materials incorporating RCAs was proposed through the randomization method. • DEM simulation results of the uniaxial compression test were close to laboratory test results. • Contact behavior and displacement of cement-treated base materials with RCAs were analyzed based on DEM. • Cement-treated base materials with RCAs can be used as subbase course and even base course if increasing cement content. • Economical and environmental benefits of utilizing RCAs in cement-treated base materials were determined. A numerical simulation of the uniaxial compression test (UCT) was conducted based on the discrete element method (DEM), to investigate the mechanical properties of CTBM incorporating recycled crushed aggregates (RCAs) arising from construction waste powder. The components of CTBM were generated via the randomization method to obtain a 2D DEM model. Then, the Linearcbond Model and Linearpbond Model were selected, and the effects of the main micro-parameters of contact models on the stress–strain curves of CTBM were clarified. The final micro-parameters were determined through the trial and error method and inversion analysis. Moreover, the micromechanical results presented that the contact forces between particles during the whole loading process increased continuously until damage occurred. And the contacts between particles failed at the middle and later loading stages, especially the tension contacts. The contact number of the Linearcbond Model reduced significantly, while that of the Linearpbond Model only decreased by 2.6%. Furthermore, the upper and lower particles moved to the mid-span of the specimens, and the particles in the middle moved to both sides when loading. The displacement on both sides was larger due to the failure of the specimen in the middle and later loading periods. The presented 2D DEM has the potential to display the mechanical characteristics of CTBM. It also provides theoretical guidance for the wide application of RCAs due to their great economic and environmental benefits. [ABSTRACT FROM AUTHOR]

• A asphalt mixture with 100% utilization of RAP for the surface layer of RAP was prepared using epoxy asphalt. • The difference between the dynamic modulus of FREAM and normal asphalt mixtures was investigated. • The effect of different aging methods on the performance of FREAM was investigated and recommendations were given for its application. With the continuous development of concepts such as "environmental protection" and "sustainable development", it is difficult for the existing technology of asphalt pavement recycling to meet the needs of efficient utilization of Recycled Asphalt Pavement(RAP). The purpose of this research is to explore the application potential of the fully recycled epoxy asphalt mixture(FREAM), which achieves 100% utilization of RAP, in asphalt pavement. By testing the dynamic modulus, the difference between FREAM and conventional asphalt mixture was explored, and the problems that need to be paid attention to when FREAM is used as the surface course were analyzed. Through two aging methods with different mechanisms, the pavement performance of FREAM before and after aging was studied, including high-temperature performance, low-temperature performance, moisture sensitivity, and fatigue performance. Through this research, it is found that the dynamic modulus of FREAM is higher than that of conventional asphalt mixture, and it has better deformation resistance. However, the influence of the difference in modulus between layers needs to be paid attention to when used as a surface course structure. The FREAM has strong resistance to long-term thermal oxidation aging, and the road performance before and after aging meets the application requirements of the surface course. However, the anti-ultraviolet aging ability of the FREAM is weak, and it is not suitable for the surface of the surface course and more suitable for the middle course and lower layer. [ABSTRACT FROM AUTHOR]

Reclaimed asphalt pavement (RAP) is often utilized in asphalt concrete due to its significant environmental gains. This study focused on the environmental impact of recycled hot mix asphalt (HMA) with RAP materials from the rotary decomposition process compared to virgin HMA and conventional recycled HMA. SMA-13-, AC-16- and AC-20-type pavements were considered using the life cycle assessment (LCA) method. The energy consumption and air emissions at various phases were determined. Multiple impact categories, including the global warming potential (GWP), eutrophication potential (EP), photochemical smog potential (POCP) and acidification potential (AP), were calculated based on the life cycle inventory (LCI) data at varying phases. The LCI results showed that the recycled HMA was superior to the virgin HMA in terms of their energy consumption and CO 2 emissions, with decline rates of approximately 10% for the AC-16 and AC-20 pavements and 5% for the SMA-13 pavement. In addition, the results indicated that two processes (the material transportation phase and the mixture production and transportation phase) contributed the most to energy consumption and carbon emissions, accounting for more than 83% overall. The life cycle impact assessment (LCIA) results revealed that all the impact categories of recycled HMA decreased greatly compared to those of virgin HMA, especially the GWP. After normalization and weighting, the significant impact category that should be given more attention was the GWP for all types of pavements. The monetized value results showed that it decreased by 10.92% for SMA-13Ⅱ compared to SMA-13Ⅰ, and by 20.85%, 30.74%, 19.53% and 32.17% for AC-16Ⅱ, AC-16Ⅲ, AC-20Ⅱ and AC-20Ⅲ, respectively, compared to that of the virgin HMA. Finally, the changes in the environmental impact of multi-rotary decomposition processes were also evaluated. And the environmental impact between the rotary decomposition process and the conventional recycling method was compared and discussed. The monetized values of AC-16-R-one-50% and AC-16-R-two-70% HMA were reduced by 8.2% and 22.8%, respectively, compared to AC-16-C-30% HMA. [ABSTRACT FROM AUTHOR]