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Erik Schlangen - One of the best experts on this subject based on the ideXlab platform.
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Self-Healing Technology for Asphalt Pavements
Self-healing Materials, 2015Co-Authors: Amir Tabakovic, Erik SchlangenAbstract:Self-Healing technology is a new field within material technology. It represents a revolution in materials engineering and is changing the way that materials behave. Incorporating Self-Healing technology into the road design process has the potential to transform road construction and maintenance processes by increasing the lifespan of roads and eliminating the need for road maintenance. By decreasing the unnecessary premature ageing of asphalt pavements, Self-Healing asphalt can reduce the amount of natural resources used to maintain road networks, decrease the traffic disruption caused by road maintenance processes, decrease CO2 emissions during the road maintenance process and increase road safety. In addition to environmental savings, Self-Healing materials have the potential to deliver significant cost savings for road network maintenance across the EU. There are three main Self-Healing technologies available for asphalt pavement design: nanoparticles, induction heating and rejuvenation. This chapter reviews all three options and outlines the future development of Self-Healing asphalt technology.
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Induction heating of asphalt mastic for crack control
Construction and Building Materials, 2013Co-Authors: Qian Liu, Shaopeng Wu, Erik SchlangenAbstract:Asphalt mastic is a Self-Healing material and it has the potential to close internal cracks by itself. In this study, an induction healing approach is developed to increase the Self-Healing capacity of asphalt mastic. Conductive additives are added to asphalt mastic to make it electrically conductive and suitable for induction heating. When micro-cracks are expected to occur in asphalt mastic, induction heating can be to improve the Self-Healing ability of asphalt mastic to close the cracks. This paper investigates the induction heating speed, bending strength and induction healing rate of asphalt mastic with different conductive additives. It was observed that asphalt mastic that contained steel wool or steel fiber can be rapidly heated using induction energy. Adding steel wool or steel fiber to asphalt mastic also increases its bending strength. Finally, the fractured asphalt mastic beams that contain steel wool and steel fiber can regain their bending strength to that of fresh reference samples with induction heating. Cracks were observed to disappear during induction heating. Based on these results, it is concluded that induction heating/healing can be used to close cracks in asphalt mastic.
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a simple model to define induction heating in asphalt mastic
Construction and Building Materials, 2012Co-Authors: Erik Schlangen, Alvaro Garcia, Martin Van De VenAbstract:Abstract It is well known that mastic is a Self-Healing material and that its Self-Healing rates are highly influenced by temperature. In [1] it was shown that it is possible to make mastic conductive and to induction-heat it. Additionally, in [2] it was shown that activation energy can be used to calculate the healing times of asphalt mastic through the Arrhenius equation. If the increase of temperature with time could be predicted, the necessary induction heating time to obtain a complete recovery can be calculated. But temperature rise in asphalt mastic through induction heating, depends on a variety of parameters such as ambient temperature, output current and material resistance. For this reason, this paper presents a simple equivalent circuit to represent the thermal heat flow equations for conductive mastic, heated though induction energy. A set of differential equations is derived to calculate the equilibrium temperatures in the mastic surface. Moreover, the model parameters have been derived through the least square method for one induction-heated mixture, which temperature was measured with an infrared camera. Finally, the main induction heating mechanisms in asphalt mastic have been identified and visualized in a foil of fibers and bitumen, which temperature has been increased though induction heating and the results have been compared to those shown in [1] .
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evaluation of the induction healing effect of porous asphalt concrete through four point bending fatigue test
Construction and Building Materials, 2012Co-Authors: Erik Schlangen, Gerbert Van Bochove, Jo Van MontfortAbstract:Abstract The objective of this paper is to evaluate the induction healing effect of steel wool reinforced porous asphalt concrete. The four point bending fatigue resistance of the beams was first studied. It was found that the fatigue resistance of these steel wool reinforced beams was quite good compared with the references in the literature. Then, fatigue life extension ratio and flexural stiffness recovery of the beams were used to show their healing effect. The fatigue life extension ratio was measured after introducing induction heating and letting the fatigue damaged beams rest. It was found that induction heating increases the healing rate of the beams and that the healing is highly microstrain-dependent with higher healing rate under high microstrain level. It was also found that the optimal heating temperature is 85 °C to obtain the best healing effect. Heating too much can cause swelling in the specimens, which will decrease the total healing produced. The fatigue damaged beams obtained extra stiffness recovery when induction heating was applied to them. Finally, it was also found that fatigue life of porous asphalt concrete can be significantly extended by applying multiple induction heating. Based on these findings, it is concluded that the self healing effect of porous asphalt concrete can be increased by induction heating the material. Additionally, the durability of porous asphalt pavement will also be improved with induction healing.
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Induction Healing of Porous Asphalt
Transportation Research Record, 2012Co-Authors: Quantao Liu, Erik Schlangen, Martin Van De VenAbstract:Research on the induction healing of porous asphalt is summarized. Steel wool is added to porous asphalt concrete to make it electrically conductive and suitable for induction heating. When microcracks occur in the material, an induction generator is used to heat the material to close the cracks by the high-temperature Self-Healing of bitumen. The electrical resistance and induction heating speed of porous asphalt concrete reinforced with steel wool are examined. Porous asphalt concrete containing steel wool is found to be electrically conductive and can be heated with induction energy. The mechanical properties of this porous asphalt are also studied. Steel wool can reinforce porous asphalt concrete by increasing its strength, particle loss (raveling) resistance, and fatigue resistance. Furthermore, the induction healing effect of this porous asphalt concrete reinforced with steel wool is evaluated. It is proved that the fatigue life of induction-healing porous asphalt can be extended significantly by the application of induction heating. It is also found that the optimal heating temperature for the best healing effect is 85°C. These findings indicate that the Self-Healing potential of porous asphalt concrete and the durability of porous asphalt pavement are improved by induction heating. Finally, a test section was paved on the Dutch A58 motorway with a porous asphalt layer containing steel wool. Because asphalt concrete exhibits better Self-Healing at higher temperatures, the future for the application of induction-healing porous asphalt concrete appears to be promising.
Herman Terryn - One of the best experts on this subject based on the ideXlab platform.
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shape memory composite smc self healing coatings for corrosion protection
Progress in Organic Coatings, 2016Co-Authors: Luntao Wang, Leping Deng, Hongchang Qian, Cuiwei Du, Da-wei Zhang, Xiaogang Li, Herman TerrynAbstract:Abstract A shape memory composite (SMC) coating with a Self-Healing ability was prepared by a facile method based on a thermoresponsive shape memory polymer (SMP) that utilized carnauba wax microparticles as the healing agent. Damages to the SMC coating was healed via heating, which triggered a two-step healing mechanism consisting of defect closure through a shape memory effect at 65 °C and then defect sealing by molten wax at 90 °C. The surface morphologies of the scratched and healed coatings as well as a wax-free SMP coating were first studied by optical stereomicroscopy and scanning electron microscopy (SEM). To assess the recovery of the coating’s barrier properties, macroscopic and localized information was obtained by electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM), respectively. The healing performance was also evaluated by comparing the macroscopic morphologies of the intact, damaged and healed coatings after long-term immersion. The results from both tests were in agreement and confirmed the key roles of carnauba wax microparticles in the complete recovery of the barrier properties of initially damaged coatings upon thermally assisted Self-Healing.
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A Multiple-Action Self-Healing Coating
Frontiers in Materials, 2015Co-Authors: Alexander Lutz, Otto Van Den Berg, Jan Wielant, Iris De Graeve, Herman TerrynAbstract:This paper describes a Self-Healing coating for corrosion protection of metals which combines two different types of Self-Healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT) was loaded into layered double hydroxide (LDH) carriers which were mixed into an acrylated polycaprolactone polyurethane based shape recovery coating and applied on Hot Dip Galvanized steel (HDG). The effect of triggered release of MBT on the protection of HDG became visible when samples with manually applied defects in the coating were immersed in 0.05 M NaCl solution (first, autonomous healing mechanism). The shape recovery (second, non-autonomous healing mechanism) was triggered by heating the samples for 2 minutes to 60°C. SEM-EDX and Raman Spectroscopy proved the presence of MBT in the LDH, in the MBT-loaded LDH in the coating and the released MBT on the HDG surface in the damaged area after being in contact with a solution containing corrosive ions. Electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET) demonstrate the corrosion protection effect of MBT in the coating with a defect and the restoration of the barrier properties of the coating after defect closure. This way, the independent mechanisms of this multi-action Self-Healing coating could be demonstrated.
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atomic force microscopy based study of self healing coatings based on reversible polymer network systems
Journal of Intelligent Material Systems and Structures, 2014Co-Authors: Joost Brancart, T Muselle, G. Scheltjens, B Van Mele, Herman TerrynAbstract:A Self-Healing polymer system is created by incorporating reversible covalent bonds into an epoxy–amine-based network structure. The Self-Healing concept is based on the reversible Diels–Alder reaction between furan and maleimide functional groups. The thermal and mechanical properties of the reversible network structure are tailored in order to achieve good Self-Healing properties for the corrosion protection of metal surfaces. Atomic force microscopy is proposed as a technique to study the Self-Healing behavior of coatings. Local thermal analysis techniques are used to study the local thermomechanical behavior of the reversible network. Nanosized defects in the coatings are made by means of nanolithography. The actual Self-Healing behavior is studied by atomic force microscopy imaging before and after the heating steps. The healing capability of elastomeric and glassy model systems is compared.
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Atomic force microscopy–based study of Self-Healing coatings based on reversible polymer network systems
Journal of Intelligent Material Systems and Structures, 2012Co-Authors: Joost Brancart, T Muselle, G. Scheltjens, B Van Mele, Herman TerrynAbstract:A Self-Healing polymer system is created by incorporating reversible covalent bonds into an epoxy–amine-based network structure. The Self-Healing concept is based on the reversible Diels–Alder reaction between furan and maleimide functional groups. The thermal and mechanical properties of the reversible network structure are tailored in order to achieve good Self-Healing properties for the corrosion protection of metal surfaces. Atomic force microscopy is proposed as a technique to study the Self-Healing behavior of coatings. Local thermal analysis techniques are used to study the local thermomechanical behavior of the reversible network. Nanosized defects in the coatings are made by means of nanolithography. The actual Self-Healing behavior is studied by atomic force microscopy imaging before and after the heating steps. The healing capability of elastomeric and glassy model systems is compared.
Alvaro Garcia - One of the best experts on this subject based on the ideXlab platform.
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influence of rheological and physical bitumen properties on heat induced self healing of asphalt mastic beams
Construction and Building Materials, 2018Co-Authors: D Grossegger, Breixo Gomezmeijide, Stefan Vansteenkiste, Alvaro GarciaAbstract:Abstract Asphaltic materials have Self-Healing properties due to the capacity of bitumen, a viscoelastic liquid with a temperature- and time-dependent viscosity, to flow and/or drain into cracks. Different types of bitumen have different adhesive and rheological properties depending on the refining process, chemical composition, and origin of the bitumen. In addition, other factors that affect the Self-Healing capacity are the resting period between traffic loads, filler content and ambient temperatures. To further investigate the influencing factors for asphalt Self-Healing for macro cracks, the authors have selected five types of bitumen, which are commonly used in road constructions, from different sources. The Self-Healing was assessed by manufacturing asphalt mastic beams and breaking these beams. Healing was induced by either convection or induction heating. The rheological and compositional properties of bitumen were correlated to the healing characteristics of the beams tested. Interestingly, the physical, rheological and chemical properties of bitumen did not influence healing properties, as the thermal expansion coefficient, surface energy and density of the bitumen used were similar. Hence, healing became similar as the influence of viscosity became minor compared to other driving forces.
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effect of air voids content on asphalt self healing via induction and infrared heating
Construction and Building Materials, 2016Co-Authors: Breixo Gomezmeijide, Harith Ajam, Pedro Lastragonzalez, Alvaro GarciaAbstract:Abstract Cracks in asphalt roads can self-heal if enough resting time is allowed. Asphalt Self-Healing is a viscosity related phenomenon that accelerates with the temperature of the material. In the present paper, asphalt Self-Healing has been induced in cracked asphalt beams with three air voids contents: 4.5%, 13%, and 21%, by exposing them at various times under infrared radiation and induction heating. Infrared heating has been used to simulate solar radiation. Results show that cracks in asphalt mixture can be completely repaired by infrared and induction heating, but the last one is more energy efficient since the effect is concentrated only on the binder instead of heating the whole asphalt mixture. Moreover, it has been observed that dense mixtures obtained better healing with low energy but the maximum healing ratios obtained by them were lower than those obtained by semi-dense and porous mixtures. A new healing model was proposed involving not only surface tension, hydrostatic forces and energy dissipation (included in previous models) but also other factors, such as differential temperature between aggregates and binder and thermal expansion.
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self healing of dense asphalt concrete by two different approaches electromagnetic induction and infrared radiation
Rilem International Conference on Mechanisms of Cracking and Debonding in Pavements 8th 2016 Nantes France, 2016Co-Authors: Harith Ajam, Breixo Gomezmeijide, Pedro Lastragonzalez, Alvaro GarciaAbstract:Cracks in asphalt mixture can self-heal if enough resting time (hours or days) is given. This is a viscosity dependent phenomenon that can be accelerated by increasing the temperature of asphalt mixture. In the present paper, the healing performance of asphalt mixture heated using infrared heating to simulate the natural solar radiation, and induction heating, a new method to increase the temperature of asphalt pavements, were compared in terms of time and healing temperature. Healing was defined as the relationship between the 3-point bending strength of an asphalt beam before and after healing. The results show that both methods reach similar and satisfactory healing rates at around 90 %. However, induction heating is more energy-efficient, since the effect is concentrated on the binder, instead of heating the whole mix. This means much shorter healing times to reach the same healing rate than with infrared radiation. Finally, it was found an optimal radiation energy, from which on, infrared radiation reduces the material healing properties.
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a simple model to define induction heating in asphalt mastic
Construction and Building Materials, 2012Co-Authors: Erik Schlangen, Alvaro Garcia, Martin Van De VenAbstract:Abstract It is well known that mastic is a Self-Healing material and that its Self-Healing rates are highly influenced by temperature. In [1] it was shown that it is possible to make mastic conductive and to induction-heat it. Additionally, in [2] it was shown that activation energy can be used to calculate the healing times of asphalt mastic through the Arrhenius equation. If the increase of temperature with time could be predicted, the necessary induction heating time to obtain a complete recovery can be calculated. But temperature rise in asphalt mastic through induction heating, depends on a variety of parameters such as ambient temperature, output current and material resistance. For this reason, this paper presents a simple equivalent circuit to represent the thermal heat flow equations for conductive mastic, heated though induction energy. A set of differential equations is derived to calculate the equilibrium temperatures in the mastic surface. Moreover, the model parameters have been derived through the least square method for one induction-heated mixture, which temperature was measured with an infrared camera. Finally, the main induction heating mechanisms in asphalt mastic have been identified and visualized in a foil of fibers and bitumen, which temperature has been increased though induction heating and the results have been compared to those shown in [1] .
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induction healing of asphalt mastic and porous asphalt concrete
Construction and Building Materials, 2011Co-Authors: Alvaro Garcia, Erik SchlangenAbstract:The objective of this paper is to detect the healing effect of asphalt mastic and porous asphalt concrete caused by induction heating. It was found that the broken mastic beams could be healed many times by induction heating. Moreover, the stiffness of porous asphalt concrete recovered more and faster when induction heating was applied to the samples. It was also found that fatigue life of porous asphalt concrete was significantly extended by induction heating. Based on these findings, it was concluded that the self healing rate of asphalt mastic and porous asphalt concrete can be increased by induction heating.
Patrick T. Mather - One of the best experts on this subject based on the ideXlab platform.
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Comparative analysis of shape memory-based Self-Healing coatings
Journal of Polymer Science Part B, 2016Co-Authors: Hossein Birjandi Nejad, Katie L. Garrison, Patrick T. MatherAbstract:Self-Healing materials exhibit the ability to repair and to recover their functionality upon damage. Here, we report on an investigation into preparation and characterization of shape memory assisted Self-Healing coatings. We built on past work in which poly(e-caprolactone) electrospun fibers were infiltrated with a shape memory epoxy matrix and delve into fabricating and characterizing a coating with the same materials, but employing a blending approach, polymerization induced phase separation. After applying controlled damage, the ability of both coatings to self-heal upon heating was investigated. In both methods, coatings showed excellent thermally induced crack closure and protection against corrosion, with the blend approach being more suitable for large-scale applications given its process simplicity. Two different approaches to the preparation of shape memory-based Self-Healing coatings were compared for their ability to heal structurally and functionally by heating. These two approaches, electrospinning versus polymerization-induced phase separation were found to feature comparable and quite complete healing, with the latter system offering the advantage of facile processing. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1415–1426
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Shape Memory Assisted Self-Healing Coating
ACS Macro Letters, 2013Co-Authors: Xiaofan Luo, Patrick T. MatherAbstract:In this communication, we report the preparation and characterization of new shape memory assisted Self-Healing (SMASH) coatings. The coatings feature a phase-separated morphology with electrospun thermoplastic poly(e-caprolactone) (PCL) fibers randomly distributed in a shape memory epoxy matrix. Mechanical damage to the coating can be self-healed via heating, which simultaneously triggers two events: (1) the shape recovery of the matrix to bring the crack surfaces in spatial proximity, and (2) the melting and flow of the PCL fibers to rebond the crack. In controlled healing experiments, damaged coatings not only heal structurally, but also functionally by almost completely restoring the corrosion resistance. We envision the wide applicability of the SMASH concept in designing the next-generation Self-Healing materials.
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linear network poly e caprolactone blends exhibiting shape memory assisted self healing smash
ACS Applied Materials & Interfaces, 2011Co-Authors: Erika D Rodriguez, Xiaofan Luo, Patrick T. MatherAbstract:Self-Healing (SH) polymers are responsive polymeric materials that can repair mechanical damage such as cracks in an autonomous fashion. In most SH polymers studies reported to date, crack closure was either unaddressed or achieved by manual intervention. Here, we report a new strategy that utilizes shape memory (SM) to prepare novel SH polymers that are capable of simultaneously closing and rebonding cracks with a simple thermal trigger. This strategy, termed "shape memory assisted Self-Healing (SMASH)", is demonstrated in a blend system consisting of cross-linked poly(e-caprolactone) network (n-PCL) with linear poly(e-caprolactone) (l-PCL) interpenetrating the network, and exhibits a combination of SM response from the network component and SH capacity from the linear component. Thermomechanical analysis revealed that the thermoset, n-PCL, demonstrates reversible plasticity -a form of shape memory where large plastic deformation at room temperature is fully recoverable upon heating. This SM action assists to close any cracks formed during deformation and/or damage while l-PCL chains tackify the crack surfaces by diffusion to the free surface and ultimately across the area of damage during the same heating step as used for SM. In our study, we investigated the controlled damage and SMASH healing of blends with varying composition using tensile testing of essential work of fracture film specimens. The healing component, l-PCL used had a high M(w) (M(w) ∼65k g/mol) to enable re-entanglement after diffusion across the interface while the shape memory component, n-PCL was prepared from PCL telechelic diacrylates and a tetrathiol cross-linker, yielding excellent shape memory. We found excellent Self-Healing of films by the SMASH mechanism, with near complete healing for l-PCL contents exceeding 25 wt %. Applications are envisioned in the area of Self-Healing bladders, inflated structure membranes, and architectural building envelopes.
Martin Van De Ven - One of the best experts on this subject based on the ideXlab platform.
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a simple model to define induction heating in asphalt mastic
Construction and Building Materials, 2012Co-Authors: Erik Schlangen, Alvaro Garcia, Martin Van De VenAbstract:Abstract It is well known that mastic is a Self-Healing material and that its Self-Healing rates are highly influenced by temperature. In [1] it was shown that it is possible to make mastic conductive and to induction-heat it. Additionally, in [2] it was shown that activation energy can be used to calculate the healing times of asphalt mastic through the Arrhenius equation. If the increase of temperature with time could be predicted, the necessary induction heating time to obtain a complete recovery can be calculated. But temperature rise in asphalt mastic through induction heating, depends on a variety of parameters such as ambient temperature, output current and material resistance. For this reason, this paper presents a simple equivalent circuit to represent the thermal heat flow equations for conductive mastic, heated though induction energy. A set of differential equations is derived to calculate the equilibrium temperatures in the mastic surface. Moreover, the model parameters have been derived through the least square method for one induction-heated mixture, which temperature was measured with an infrared camera. Finally, the main induction heating mechanisms in asphalt mastic have been identified and visualized in a foil of fibers and bitumen, which temperature has been increased though induction heating and the results have been compared to those shown in [1] .
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Induction Healing of Porous Asphalt
Transportation Research Record, 2012Co-Authors: Quantao Liu, Erik Schlangen, Martin Van De VenAbstract:Research on the induction healing of porous asphalt is summarized. Steel wool is added to porous asphalt concrete to make it electrically conductive and suitable for induction heating. When microcracks occur in the material, an induction generator is used to heat the material to close the cracks by the high-temperature Self-Healing of bitumen. The electrical resistance and induction heating speed of porous asphalt concrete reinforced with steel wool are examined. Porous asphalt concrete containing steel wool is found to be electrically conductive and can be heated with induction energy. The mechanical properties of this porous asphalt are also studied. Steel wool can reinforce porous asphalt concrete by increasing its strength, particle loss (raveling) resistance, and fatigue resistance. Furthermore, the induction healing effect of this porous asphalt concrete reinforced with steel wool is evaluated. It is proved that the fatigue life of induction-healing porous asphalt can be extended significantly by the application of induction heating. It is also found that the optimal heating temperature for the best healing effect is 85°C. These findings indicate that the Self-Healing potential of porous asphalt concrete and the durability of porous asphalt pavement are improved by induction heating. Finally, a test section was paved on the Dutch A58 motorway with a porous asphalt layer containing steel wool. Because asphalt concrete exhibits better Self-Healing at higher temperatures, the future for the application of induction-healing porous asphalt concrete appears to be promising.
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Two Ways of Closing Cracks on Asphalt Concrete Pavements: Microcapsules and Induction Heating
Key Engineering Materials, 2009Co-Authors: Alvaro Garcia, Erik Schlangen, Martin Van De VenAbstract:It is well known that asphalt concrete is a self healing material: immediately after both faces of a crack are in contact, the diffusion of molecules from one face to the other starts. If there are no more loads, this process takes place until the crack has completely disappeared and the material has recovered its original resistance [1]. To increase this healing rate two methods are proposed. The first one is a passive Self-Healing mechanism. Embedded encapsulated chemicals are used in the binder. When microcracks start appearing in the binder due to the combination of ageing and accumulated damage, they break the capsules and the chemicals enter the binder by diffusion. These chemicals repair the material, decreasing the stiffness and increasing the healing rates of bitumen. The second approach makes use of an active self healing mechanism. Local heating inside the material is used to repair the binder and to improve the properties again. This is realized by adding conductive particles to the binder and using induction energy to increase the temperature. These methods are a fairly new concept in the asphalt industry.