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Bitumen emits a large amount of volatile organic compounds (VOCs) during the production and construction of asphalt mixture, which can cause both environmental hazards and health risks. In this study, a setup was designed to collect the VOCs released by base and crumb rubber-modified bitumen (CRMB) binders and their composition was characterized by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Next, organic montmorillonite (Mt) nanoclay was added into CRMB binder and its inhibiting effect on the VOCs emission of the binder was investigated. Finally, the VOCs emission models for the CRMB and Mt-modified CRMB (Mt-CRMB) binders were established according to reasonable assumptions. The results indicated that the VOCs emission of CRMB binder was 3.2 times larger than that of the base binder. Due to its intercalated structure, the nanoclay can reduce the VOCs emission of CRMB binder by 30.6%. Especially, its inhibition effects on alkanes, olefins, and aromatic hydrocarbons were more significant. After finite element verification, the established model based on the Fick’s second law can describe the emission behavior of CRMB and Mt-CRMB binders well. Overall, the Mt nanoclay can be used as an effective modifier to inhibit the VOCs emission of CRMB binder.

Calcium alginate capsules containing rejuvenators represent a promising method for asphalt concrete premaintenance, but their healing capacities under lower temperature conditions are still unknown. This paper investigated the healing performance of asphalt concrete containing calcium alginate capsules at low service temperatures. The Ca-alginate capsules were synthesized, and their morphology, compressive strength, thermal resistance, and relative oil content were evaluated. Besides, evaluations for the healing of asphalt concrete and the rejuvenator-release ratio of the capsules were determined via fracture-healing-refracture testing and Fourier-transform infrared spectrum experiments. Meanwhile, the glass transition temperature and rheological property of asphalt binder after compressive loading under different temperatures were explored via a differential scanning calorimeter and dynamic shear rheometer. The results showed that the capsules had good thermal resistance and mechanical strength. The capsules released less oil under −15, −10, and −5 °C than at 20 °C, and the healing ratios of the asphalt concrete with the capsules at −15, −10, and −5 °C were obviously lower than that at 20 °C. The released rejuvenator from the capsules could decrease the complex modulus and glass transition temperature of the asphalt binder. When compared with low service temperatures, the asphalt binder containing the capsules and serving at a high temperature has a better softening effect and low-temperature performance due to more oil being released.

Calcium alginate capsules encapsulating rejuvenator are a promising self-healing technology for asphalt pavement, but the effects of different healing agents on the self-healing performance of asphalt concrete has not been considered. In view of this, this paper aimed at exploring the effects of calcium alginate capsules containing different healing agents on the self-healing properties of asphalt concrete. Three types of capsules with sunflower oil, waste cooking oil and commercial rejuvenator were fabricated via the orifice-coagulation bath method and the interior structure, mechanical strength, thermal stability and oil content of the prepared capsules were characterized. The healing levels of asphalt mixtures with different capsules under different loading cycles and stress levels were evaluated. Furthermore, the saturates, aromatics, resins and asphaltenes (SARA) fractions and rheological property of extracted asphalt binder within test beams with different capsules after different loading conditions were assessed. The results indicated that all the three types of capsules meet the mechanical and thermal requirement of mixing and compaction of asphalt mixtures. The healing levels of test beams containing vegetable oil capsules were higher than that of waste cooking oil capsules and industrial rejuvenator capsules. The strength recovery ratio and fracture energy recovery ratio of test beams with vegetable oil capsules reached 82.8% and 96.6%, respectively, after 20,000 cycles of compressive loading at 1.4 MPa. The fracture energy recovery ratio of the waste cooking oil capsules also reached as high as 90%, indicating that waste cooking oil can be used as the healing agent of calcium alginate capsules to improve the self-healing property of asphalt mixture. This work provides a significant guide for the selection of healing agent for self-healing capsules in the future.

Cracks are inevitable during the service life of asphalt pavement and the water at the fracture surfaces tends to cause the grouting materials to fail. Studies have shown that the catechol groups in adhesion proteins secreted by mussels can produce strong adhesion performance in the water. In this paper, the mussel-like adhesive L-Dopa Methacrylic anhydride (L-DMA) was prepared based on the concept of bionic design and used to improve the properties of asphalt. By using Fourier-transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA), the thermal stability and structural composition of L-DMA were investigated. Then, the rheological and low-temperature properties of L-DMA-modified asphalt were investigated using the dynamic shear rheological (DSR) test and bending beam rheological (BBR) test. Moreover, the modification mechanism was explored by FTIR. It was found that L-DMA can be effectively synthesized and has good thermal stability. The incorporation of L-DMA increases the composite modulus, viscosity, creep recovery rate and rutting factor of asphalt binder, resulting in an enhancement of its high-temperature performance. At a high L-DMA content of 10%, the low-temperature performance of the modified asphalt was enhanced. The modification of L-DMA to asphalt is mainly a physical process. Hydrogen bonds and conjugated systems generated by the introduction of catechol groups enhance the adhesion properties of asphalt. In general, L-DMA improves the properties of asphalt and theoretically can improve the water resistance of asphalt, which will be explored in future research.

Calcium alginate capsules within asphalt concrete can gradually release interior asphalt rejuvenator under cyclic loading to repair micro cracks and rejuvenate aged asphalt in-situ. However, asphalt pavement will become aged due to environmental and traffic factors during the service period. In view of this, this paper investigated the effect of ageing on the healing properties of asphalt concrete containing calcium alginate/attapulgite composite capsules under cyclic loading. The capsules were fabricated using the orifice-bath method and the morphological structure, mechanical strength, thermal stability, oil release ratios and healing levels of capsules in fresh, short-term ageing and long-term ageing asphalt concrete were explored. The results indicated that the different ageing treatments would not damage the multi-chamber structure nor decrease the mechanical strength of capsules but would induce the capsules release oil prematurely. The premature oil released from capsules in turn can offset the ageing effect owing to ageing treatment. The short-term ageing and long-term ageing plain asphalt mixtures gained strength recovery ratios of 39.3% and 34.2% after 64,000 cycles of compression loading, while the strength recovery ratios of short-term ageing and long-term ageing asphalt mixtures containing capsules were 63.5% and 54.8%, respectively.

To meet the needs of the road industry for maintenance operations, a new cement emulsified bitumen mixture (CEBM) with early-strength, self-compacting, and room-temperature construction characteristics was designed. The strength formation mechanism of CEBM was revealed with a scanning electron microscope (SEM) and the surface free energy (SFE) theory. The mechanical properties and road performance of the CEBM were investigated extensively. The results show that before the demulsification of emulsified bitumen, the SFE of the bitumen–aggregate–water three-phase system was reduced due to the replacement of the bitumen–aggregate interface with water. The adhesion work between the emulsified bitumen and the aggregate is negative, which means the adhesion between the emulsified bitumen and the aggregate will not occur spontaneously due to the existence of water. The liquid emulsified bitumen improves the workability of the mixture and ensures that the mixture can be evenly mixed and self-compacted. After demulsification, the work of adhesion between the residual bitumen and the aggregate is positive, which means residual bitumen and aggregate can bond spontaneously. In addition, the hydration products of cement and aggregate form a skeleton, and the emulsified bitumen film wraps and bonds the cement and aggregate together, creating strength. The emulsified bitumen, cement content, and curing conditions have significant effects on the stability of CEBM. The recommended dosage of emulsified bitumen and cement is 8% and 8–10%, respectively. This material integrates the hardening effect of cement and the viscoelastic performance of bitumen and has good workability, mechanical properties, and road performance. Therefore, the CEBM is technically feasible for application to bitumen pavement.

Green production of asphalt materials is very important to promote energy savings and emission reduction during the construction and maintenance of asphalt pavement. A low-temperature construction additive (LCA) made from the waste plastic and waste rubber is proposed, which belongs to a class of environmentally friendly additives for asphalt mixtures. Marshall stability was tested to evaluate the mechanical performance of LCA-modified asphalt mixtures (LCA-AMs). In order to determine the best preparation parameters of LCA-AMs, the influence of the content and LCA addition method on the strength of LCA-AMs was studied. In addition, the impact of epoxy resin (ER) on the mixtures’ performances was evaluated. The results show that the LCA can significantly reduce the formation temperature of asphalt mixtures, and the resulting asphalt mixtures have good workability in a lower temperature range (90–110 °C). The ER should be added to the LCA-AMs after 4 h of curing. All the volumetric properties satisfy the technical requirements. The low-temperature crack resistance and fatigue resistance of LCA-AMs were obviously improved with appropriate dosages of ER, which can effectively improve the mechanical performance of the asphalt mixtures. The ER can significantly increase the rutting resistance and water sensitivity of LCA-AMs, therefore making it feasible to improve the mixture performance by the enhancement provided by a low dosage of ER.

This study evaluated the effect of two encapsulation methods (i.e., dropping funnel and syringe pump), two concentrations of the alginate-based encapsulating material (2%, and 3%), and three oils as bitumen rejuvenators (virgin sunflower oil, waste cooking oil, and virgin engine oil) on the morphological, physical, chemical, thermal, and mechanical properties of encapsulated rejuvenators for asphalt self-healing purposes. A general factorial design 2 × 2 × 3 was proposed to design 12 different Ca-alginate capsules. Significant differences on the morphological, physical, and mechanical properties of the capsules were analysed by three-way ANOVA and Tukey HSD Post Hoc analyses. The effect of the type of oil on the self-healing capacity of cracked bitumen samples was also evaluated. The main results showed that the design parameters and their interactions significantly affected the morphological, physical, and mechanical properties of the capsules. Capsules synthesised via syringe pump method, with virgin cooking oil and 2% alginate was the most appropriate for asphalt self-healing purposes since its uniform morphology, encapsulation efficiency up to 80%, thermal degradation below 5% wt., and compressive strength above the reference asphalt compaction load of 10 N. Finally, the healing tests showed that virgin cooking oil can be potentially used as a rejuvenator to promote asphalt crack-healing.

To investigate the effects of different wavelength ranges of UV lights on chemical compositions and macro-properties of asphalt, three UV lights were used to conduct the aging test of asphalt for 1–288 h. The elemental analysis and Fourier transform infrared spectroscopy (FTIR) were performed to analyze the chemical changes of asphalt, the surface micro-topographies of asphalt before and after UV aging were studied by atomic force microscopy (AFM). In addition, the physical performance, viscosity and rheological performance of asphalt was studied with softening point test and dynamic shear rheometer (DSR), respectively. The chemical compositions and structures analyses show that the oxidation mechanism exists during the UV aging of asphalt binder. The numbers of bee-like structures in AFM height figures decrease obviously after UV aging, meanwhile the sizes of which increase. The relationships of RCC, RCS and SPI values with UV expose time follow a power function model in the first 24 h, while follows a liner model after 24 h. UV lights with different wavelength ranges have significantly different effects on the chemical compositions and macro-properties of asphalt. The UV 350–370 nm has the most obvious aging effect on asphalt binder, second is the UV 340–380 nm, the UV 200–400 nm has the lightest aging effect.

In this paper, the sustainability of induced healing asphalt pavement is demonstrated by comparing the impact of asphalt pavement maintained by induced healing asphalt pavement technology and traditional maintenance methods (such as milling and overlaying). The functional unit selected is a 1-km lane with an analysis period of 20 years. The stages to be considered are material manufacturing, paving, maintenance, milling and demolition. Two case studies were analyzed to assess the impact of different technologies on the energy consumption and environmental performance of each maintenance alternative. By comparing the energy consumption and environmental emissions of the whole life cycle of pavement under the two technical conditions, the results show that the total energy consumption of traditional asphalt pavement is about 2.5 times that of induction-healed asphalt pavement, and the total greenhouse gas (GHG) emissions of the former are twice as much as that of the latter.

Self-healing of cracks in cementitious materials using healing agents encapsulated in microcapsules is an intelligent and effective method. In this study, microcapsules were prepared by the melt–dispersion–condensation method using microcrystalline wax as the shell and E-51 epoxy resin as the healing agent. The effects of preparation process parameters and microcrystalline wax/E-51 epoxy resin weight ratio on the core content, particle size distribution, thermal properties, morphology, and chemical composition of microcapsules were investigated. The results indicated that the optimal parameters of the microcapsule were microcrystalline wax/E-51 epoxy resin weight ratio of 1:1.2, stirring speed of 900 rpm, and preparation temperature of 105 °C. The effects of microcapsules on pore size distribution, pore structure, mechanical properties, permeability, and ultrasonic amplitude of mortar were determined, and the self-healing ability of mortar with different contents of microcapsules was evaluated. The optimal content of microcapsules in mortars was 4% of the cement weight, and the surface cracks of mortar containing microcapsules with an initial width of 0.28 mm were self-healed within three days, indicating that microcapsules have excellent self-healing ability for cementitious materials.

Traditional asphalt mixtures can't absorb microwave energy efficiently, which limits the development of microwave heating technology in the field of road maintenance. Based on the microwave heating characteristics of basalt aggregates, the overall microwave self-healing rate of the asphalt mixture can be enhanced. The basalt was tested by XRF, XPS, XRD and electromagnetic parameters to reveal its microwave heating mechanism. Through the heating rate test, SCB test and fatigue test of asphalt mixture, its heating characteristics, flexural strength, fatigue resistance and self-healing performance were studied. The results showed that the excellent wave-absorbing properties of basalt are highly correlated with the elements of Si, Fe and Al. Its TanδM was slightly larger than TanδE, which indicated that basalt can absorb microwave energy through dielectric loss and magnetic loss. The aggregate type and particle size both affected the microwave heating rate of the aggregates. After microwave heating, the flexural strength and fatigue resistance of asphalt mixture with basalt and limestone aggregates can recover at least 65% and 23% respectively.

Conventional asphalt mixture has poor microwave absorbing performance and microwave heating efficiency. Based on the characteristics of dielectric loss of scrap tire pyrolysis carbon black (PCB), it is proposed to improve the microwave absorbing performance and self-healing rate of bitumen. The phase composition and electromagnetic parameters of PCB were tested to reveal its microwave heating mechanism. The preparation parameters, heating characteristics and self-healing properties of PCB modified bitumen were studied through the dispersion uniformity test, microwave heating test and SCB test. The main phases of PCB are microwave absorbing carbon and silicon, indicating that PCB is a good electric loss microwave absorbing material. 40 min is the recommended mixing time of 15% PCB modified bitumen. PCB's dosage, microwave frequency and microwave heating time have significant effects on the microwave heating characteristics of PCB modified bitumen. PCB can improve high-temperature stability, thermal conductance, heat storage capacity and self-healing rate of bitumen.

Calcium alginate capsule encapsulating rejuvenators are a new approach to enhance the self-healing property of asphalt, but the release and self-healing properties of calcium alginate capsu...

In this work, the ZnS nanowires was synthesized on Au-coated Si substrate by a vapor phase transport (VPT) method. The morphology and structure of the as-synthesized ZnS nanowires were studied through scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Under excitation of the femtosecond (fs) pulsed laser at 650 nm, a strong ultraviolet (UV) emission centered at 343 nm was observed. The peak position and the relationship between the emission intensity and the excitation intensity demonstrated that the UV photoluminescence (PL) be induced by the two-photon absorption (2PA) process. The characteristics and the generation process of the above nonlinear optical phenomena were investigated in detail.

This paper re-evaluates the effect of sunflower oil capsules on the mechanical and self-healing properties of dense-graded asphalt mixtures. Different percentages of capsules (0.50 wt%, 0.75 wt% and 1.00 wt%) were mixed into dense asphalt. The influence of capsules on the properties of asphalt such as density, indirect tensile strength, particle loss, fatigue life, and self-healing, has been investigated. The distribution and integrity of the capsules has been also evaluated by means of CT Scans. It has been proven that capsules can survive the mixing and compaction process of asphalt mixture, do not decrease its mechanical properties and they rupture and release the oil under a high compression loading. Higher capsule content in the mixture resulted in higher oil release ratios. Furthermore, the oil released from the capsules significantly increased the self-healing capability of mixtures. Results from previous research were validated, where it had been found that 0.5% of capsules is the optimal content to obtain good mechanical performance, without affecting the rheological properties of dense-graded asphalt mixtures.

The idea of prolonging the service life of asphalt mixture by improving the self-healing ability of asphalt has received extensive attention in recent years. In view of this, this work synthesized three kinds of encapsulating rejuvenator fibers to improve self-healing properties of asphalt mixtures. A series of characterizations were performed to study the morphology, chemical structure and thermal stability of the three kinds of fibers. Subsequently, the road performance of asphalt mixture containing the fiber were investigated, which included high and low temperature, water sensitivity and fatigue performances. Finally, the self-healing performance of asphalt mixture containing the fiber was investigated by 3PB test. The results revealed that the three kinds of encapsulating rejuvenator fibers were successfully synthesized. The fibers had excellent thermal stability, which met temperature requirements in the mixing and compaction process of asphalt mixtures. Road performance of asphalt mixture containing the fiber met the requirements. Self-healing ability of asphalt mixture containing the fiber was improved. Synergistic action of temperature and rejuvenator could further significantly improve the self-healing ability of the asphalt mixture.

Induction heating is a valuable technology to repair asphalt concrete damage inside. However, in the process of induction heating, induced particles will release a large amount of heat to act on asphalt binder in a short time. The purpose of this paper was to study the effect of induction heating on asphalt binder aging in steel fibers modified asphalt concrete. The experiments were divided into two parts: induction heating of Dramix steel fibers coated with asphalt binder (DA) and steel wool fibers modified asphalt concrete. After induction heating, the asphalt binders in the samples were extracted for testing aging indices with Fourier Transform Infrared (FTIR), Dynamic Shear Rheometer (DSR), and Four-Components Analysis (FCA) tests. The aging of asphalt binder was analyzed identifying the change of chemical structure, the diversification of rheological properties, and the difference of component. The experiments showed that the binder inside asphalt concrete began aging during induction heating due to thermal oxygen reaction and volatilization of light components. However, there was no peak value of the carbonyl index after induction heating of ten cycles, and the carbonyl index of DA was equivalent to that of binder in asphalt concrete after three induction heating cycles, which indicated the relatively closed environment inside asphalt concrete can inhibit the occurrence of the aging reaction.

Calcium alginate capsules can release internal rejuvenator under cyclic loading to repair cracks and rejuvenate aged asphalt, thus being a promising preventive maintenance technology for asphalt pavement. However, this cyclic loading induced oil release pattern is passive and cannot ensure timely release of rejuvenator from the capsules at due time. In view of this, this paper prepared a kind of novel calcium alginate capsules that could release internal healing agent rapidly under microwave excitation. Calcium alginate/nano-Fe3O4 composite capsules were synthesized by sharp hole coagulation bath method. The morphology, mechanical strength, thermal stability and rejuvenator content of the capsules were characterized by a series of tests. Meanwhile, the surface temperature distribution and oil release ratio of the capsules under microwave irradiation were quantitatively analyzed. The results showed that the calcium alginate/nano-Fe3O4 composite capsules had obvious multi-chambers structure with rejuvenator encapsulated inside. The mechanical strength and thermal stability of the capsules meet the requirements of mixing and compaction of asphalt mixtures. Most importantly, the capsules could release internal rejuvenator under short time irradiation of low-frequency microwave. In short, the introduction of nano-Fe3O4 provided calcium alginate capsules an effective oil release capacity under microwave irradiation, which is expected to improve the self-healing ability of asphalt pavement containing capsules actively.

Self-healing capability of the asphalt mixtures containing encapsulated healing agent can be affected by different water components as results of their exposure to aggressive environmental conditions such as the acid rain or saline-alkali solutions in coastal areas. In view of this, this paper aims to study the effect of harmful water environments on the self-healing capability of asphalt mixtures containing a kind of novel composite fibers. The Ca-alginate/SiO2 composite fibers encapsulating healing agent was synthesized by using a microfluidic device. Several tests were conducted to characterize the micromorphology, thermal stability and mechanical properties of the fibers. Effectiveness of the composite fibers in asphalt was observed by fluorescence microscopy. Additionally, three-point bending test was performed to measure the effects of different water environments (including acid, alkali and salt-water solutions) on the self-healing properties of asphalt mixtures with, and without fibers. Furthermore, the mechanism of the effect of different water environments on the self-healing performance of the asphalt mixture was studied by Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) analysis. Main results showed that the composite fiber encapsulated 61.9 wt% of healing agent, and the fibers could meet the temperature and mechanical requirements during the manufacturing process of asphalt mixture. The composite fiber worked and enhanced self-healing capability of asphalt. Harmful water environments did not weaken the effect of the composite fiber. Compared with the drying condition, the self-healing property of asphalt mixtures containing the composite fibers was further improved after being immersed in alkali and salt-water environment. The results indicated that the sodium ions in the alkaline solution and the salt solution could undergo a de-crosslinking chemical reaction with calcium alginate in the fiber wall, as a result of which more healing agent leaked out to soften and rejuvenate asphalt. In short, the composite fibers encapsulating healing agent worked, and these were successfully applicable into asphalt mixture under different water environments.

When a fire occurs in a tunnel, the instantaneous high temperature and smoke cause great danger to people. Therefore, the asphalt pavement material in the tunnel must have sufficient fire resistance. In this study, the effects of aluminum hydroxide and layered double hydroxide on the fire resistance of styrene-butadiene-styrene (SBS) polymer-modified asphalt was investigated. The fire resistance of the asphalt was evaluated by using a limiting oxygen index (LOI). The impact of aluminum hydroxide (ATH), layered double hydroxide (LDHs), and mixed flame retardant (MFR) on LOI was studied. The synergistic fire resistance mechanism of ATH and LDHs in asphalt binder was analyzed by using an integrated thermal analyzer‒mass spectrometry combined system (TG-DSC-MS) and Fourier transform infrared spectrometer (FTIR). The experimental results indicated that the main active temperature range of these flame retardants was 221&ndash, 483 &deg, C. The main components of smoke were methane, hydroxyl, water, carbon monoxide, aldehyde, carbon dioxide, etc. The addition of flame retardants could inhibit the production of methane, carbon monoxide, and aldehyde. Moreover, due to the good synergistic effects of ATH and LDHs, 20 wt % MFR had the best fire resistance.

This paper investigates the heating characteristics and induced healing efficiencies of asphalt mixture containing steel fiber under induction heating and microwave heating. The heating characteristics of an asphalt mixture with different heating methods were studied with an infrared camera. The healing performance of the asphalt mixture specimens in different healing conditions were investigated by observing the crack closure and testing the fracture resistance recovery after healing. The results showed that the heating speed at the surface of asphalt mixture with induction heating was much higher than that with microwave machine heating, under a similar output power and the same method of radiation. While the temperature distribution within the asphalt mixture under induction heating was quite uneven, microwave heating resulted in a more uniform temperature distribution. The effective heating depth of microwave heating is much higher than that of induction heating. Gradient healing occurred within the sample heated with induction healing, while a uniform healing effect can be achieved with microwave heating.

The aging effect of ultraviolet (UV) radiation on bitumen has gained increasing attention from researchers, resulting in the emergence of a new method to simulate the UV aging that occurs during the service life of bitumen. However, the UV aging degree is closely related to bitumen thickness and the effect of UV radiation on aging depth is not clear. The relationship between ultraviolet (UV) radiation and bitumen UV aging depth was investigated in this paper. Three groups of samples were UV aged using different aging procedures to investigate the bitumen aging mechanism of UV radiation. The results from the first group showed that UV aging depth increased along with aging time. After aging for five hours, the complex modulus of the second and third layers increased. The second group’s results indicated that the aging effect of ozone was small and that the increase in aging depth was uncorrelated with ozone. The results from the third group showed that the transmittance of bitumen increased after UV aging and that the real reason why aging depth increased was permeation.

Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO2 content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

In this work, ZnS-based one-dimensional nanoribbons were synthesized by a simple thermal evaporation method. The highly crystalline fringes exhibit the wurtzite structure, growing mainly along the [001] or [100] direction. The optical absorption spectra showed that the optical absorption band edge of the pure ZnS nanoribbons exhibit an obvious blue shift compared to that of the Mn-doped ZnS. Strong emission band centered at 343 nm has been found from the PL spectrum of the pure ZnS nanoribbons, while a weak defect-related emission centered at 580 nm also was discovered with the dopant of Mn element. Combined with all the measurements, the growth mechanism and the electron transition process were discussed.

In this paper, steel slag/steel fiber composite asphalt mixture were prepared. The effects of the addition of steel slag and/or steel fibers on the mechanical, thermal, induction heating and healing properties of asphalt mixture were investigated. The results showed that adding steel slag and/or steel fibers improves the water stability, particle loss resistance and fracture energy of asphalt mixtures. The addition of steel fibers increased the thermal conductivity and thermal diffusion of the asphalt mixture, and steel slag showed a reverse effect. Steel slag asphalt mixture cooled more slowly than steel fiber asphalt mixture, which is beneficial to crack healing of asphalt mixture. The composite of steel fibers and steel slag can enhance the induction heating speed, heating homogeneity and thus enhance the induction healing ratio of asphalt mixture. It is concluded that steel slag/steel fibers composite asphalt mixture achieves good mechanical and induction healing properties.

The objective of this paper is to evaluate the healing capacity of steel wool–reinforced porous asphalt concrete. The healing is initiated with induction heating. Bending fracture tests on an elastic foundation are used to prove the healing mechanism. Porous asphalt concrete beams on an elastic foundation were fractured at 5°C; subsequently, they were heated with induction energy, and finally fractured again. The recovered fracture resistance of the beams was used as a healing indicator. Totally fractured porous asphalt beams can regain 78.8% of their bending resistance (strength) when induction heating is applied. It was also found that the optimal heating temperature is 85°C for porous asphalt beams to obtain the highest strength recovery. Reheating of the fractured beams does not decrease the recovery of the flexural resistance, which means that the heating can be repeated when cracks return. On the basis of these findings, it is expected that the healing potential of porous asphalt concrete an...

Ceramic fiber, with a major composition of Al2O3 and SiO2, has advantages of stability at relatively high temperature, big specific surface area and resistance to external mechanical vibration. It has the potential contribution of improving the rutting resistance and temperature sensitivity of modified asphalt binder by proper modification design. In this research, ceramic fiber was introduced into both pen 60/80 and pen 80/100 asphalt binder by different weight ratios. An asphalt penetration test, softening point test, ductility test and dynamic viscoelastic behavior were conducted to characterize and predict the ceramic fiber modified asphalt mortar (CFAM). Research results indicated that the ceramic fiber has a great effect on reinforcement of asphalt, which makes the asphalt stiffer so that the asphalt can only undertake less strain under the same stress. The heat insulation effect of the ceramic fiber will improve the temperature stability. Complex modulus and phase angle results indicate that the ceramic fiber can significantly enhance the high temperature resistance of soft binder.

Pirating various forms of intellectual property (IP) causes great economic loss to intellectual property rights (IPR) holders. IPR protection is becoming a key issue in our highly networked world. In order to further deepen our understanding of how to protect IPR and enhance information interchange and knowledge sharing among related entities, ontologies for IPR protection are proposed. This study contains three parts, which are developed to deal with different perspectives in this domain. The first part presents a static ontology, i.e. a hierarchy framework for the domain language, including primarily classes of participants, classes of IP works, classes of activities, and relations between these classes. In the second part, a dynamic ontology is shown to illustrate the IPR protection process. Thirdly, a causal map is used to demonstrate how classes of IPR protection methodologies are causally related with classes of IP piracy methodologies. Finally, the case of Tomato Garden is offered to demonstrate how the proposed ontologies are used in the real world. In respect of the ontology, it is first helpful to gain a comprehensive understanding of domain knowledge of IPR protection; second, IPR protection systems' design and development in this domain are facilitated and supported by these ontologies; third, the proposed ontologies are united in the Ontology Web Language (OWL) and the OWL rules languages framework, both of which are machine readable.

In recent decades, researchers have revealed the great healing potential of asphalt and proposed various novel methods to inspire and improve the self-healing capacity of asphalt aimed to prolong the service life of asphalt pavement. In this review, up to date research progresses in induction healing and embedded rejuvenator encapsulation are presented, respectively. Meanwhile, the trial section applications of induction healing and capsule healing are highlighted, which show promising results. Finally, some recommendations for the future development of self-healing asphalt are proposed.

This work aims to develop an original alginate micro-emulsion combining with droplets microfluidic method to produce multinuclear Ca-alginate microcapsules containing rejuvenator for the self-healing of bituminous binder. The sizes of the Ca-alginate microcapsules could be easily controlled by tuning flow rates of the continuous and dispersed phases. The addition of a surfactant Tween80 not only improved the stability of the emulsion, but it also effectively reduced the size of the microcapsules. Size predictive mathematical model of the microcapsules was proposed through the analysis of fluid force. Optical microscope and remote Fourier infrared test confirmed the multinuclear structure of Ca-alginate microcapsules. Thermogravimetric analysis showed that the microcapsules coated with nearly 40% rejuvenator and they remained intact during the preparation of bitumen specimen at 135 °C. Micro self-healing process of bituminous binder with multinuclear Ca-alginate microcapsules containing rejuvenator was monitored and showed enhanced self-healing performance. Tensile stress-recovery test revealed that the recovery rate increased by 32.08% (in the case of 5% microcapsules), which meant that the Ca-alginate microcapsules containing rejuvenator could effectively enhance the self-healing property of bituminous binder.