A Review of Asphaltic Crack Healing Approaches and Its Mechanism

The concept of self-healing has an excellent potential to extend the life of asphalt pavement. This technology can be considered a sustainable technology due to its ability to reduce the utilization of asphalt mixture production materials used for road maintenance, polluting the environment. It is a complex physicochemical process wherein the molecular diffusion healing mechanisms in asphalt materials are inspired by self-healing polymeric systems, which describe the self-recovery behaviors based on polymer chain dynamics. Several methods have been adopted to improve the self-healing of asphalt, one of which is induction healing. It is the process of heating the asphalt pavement incorporated with an electrically conductive material such as steel fibers, wherein asphalt healing is undertaken via electric field induction. Induction healing via induction heating occurs with eddy current where the electric current flows within the conductive fibers when magnetically susceptible under the magnetic field. Microwave heating is another self-healing method similar to induction in which magnetic radiation is employed to treat asphalt mixtures instead of the electric field-induced induction healing processes. The conductive fibers can absorb the electromagnetic (EM) waves to convert them into heat energy through doublet polarization, interface polarization, and electrical conduction dissipation when placed in the microwave field. These two types of heating systems, which are induction heating and microwave heating, are compared and discussed thoroughly in this study. Finally, some recommendations for the future development of self-healing asphalt are proposed.

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Conductive Compartmented Capsules Encapsulating a Bitumen Rejuvenator

Processes ◽

10.3390/pr9081361 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1361

Author(s):

Amir Tabaković ◽

Joseph Mohan ◽

Aleksandar Karač

Keyword(s):

Production Process ◽

Induction Heating ◽

Asphalt Pavement ◽

Asphalt Mixture ◽

Thermal Characteristics ◽

Iron Particle ◽

Uniaxial Compression Test ◽

Self Healing ◽

Healing System ◽

Alginate Capsules

This paper explores the potential use of conductive alginate capsules encapsulating a bitumen rejuvenator as a new extrinsic self-healing asphalt method. The capsules combine two existing self-healing asphalt technologies: (1) rejuvenator encapsulation and (2) induction heating to create a self-healing system that will provide rapid and effective asphalt pavement repair. The work presents a proof of concept for the encapsulation process, which involves embedding the capsules into the bitumen mortar mixture and the survival rate of the capsules in the asphalt mixture. A drip capsule production process was adopted and scaled up to the production of 20l wet capsules at rate of 0.22 l/min. To prove the effectiveness and its ability to survive asphalt production process, the capsules were prepared and subjected to thermogravimetric analysis (TGA) and uniaxial compression Test (UCT). The test results demonstrated that the capsules had suitable thermal characteristics and mechanical strength to survive the asphalt mixing and compaction process. Scanning electron microscopy (SEM) was employed to investigate physiological properties, such as rejuvenator (oil) and iron particle distribution, within the capsules. The electrical resistance tests proved that the capsules were capable of conducting electrical current. The capsules were also tested for their conductive properties in order to determine whether they are capable of conducting and distributing the heat once subjected to induction heating. The results showed that capsules containing higher amounts of iron (alginate/iron powder in a ratio of 20:80 by weight) can efficiently conduct and distribute heat. To prove its success as an asphalt healing system, conductive alginate capsules encapsulating a bitumen rejuvenator were embedded in a bitumen mortar mix. The samples where then subjected to local damaging and healing events, and the degree of healing was quantified. The research findings indicate that conductive alginate capsules encapsulating a bitumen rejuvenator present a promising new approach for the development of an extrinsic self-healing asphalt pavement systems.

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Electrical, Thermal and Induction Heating Properties of Dense Asphalt Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.723.303 ◽

2013 ◽

Vol 723 ◽

pp. 303-311 ◽

Cited By ~ 1

Author(s):

Alvaro Garcia ◽

Jose Norambuena-Contreras ◽

Manfred N. Partl

Keyword(s):

Induction Heating ◽

Asphalt Concrete ◽

Asphalt Mixture ◽

Void Content ◽

Steel Wool ◽

Electrically Conductive ◽

Wool Fibers ◽

Conductive Fibers ◽

Different Diameters ◽

Air Void

Induction heating consists in adding electrically conductive fibers to the asphalt mixture and heating them with an induction heating device. But still, the factors that affect the increase of temperature are not well-known. With this purpose, 25 different mixtures, with the same aggregates distribution and amount of bitumen, but with 2 different lengths, 4 different quantities, and 4 different diameters of steel wool fibers have been considered. The influence of fibers on the air void content, electrical and thermal conductivity and on the induction heating of dense asphalt concrete has been studied. It was found that steel wool fibers increase slightly the electrical and thermal conductivities of dense asphalt concrete. Finally, it has been observed that the temperature reached due to the induction heating, increases with the number of fibers in the mixture and with their diameter.

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Molecular dynamics simulation insight into the temperature dependence and healing mechanism of an intrinsic self-healing polyurethane elastomer

Physical Chemistry Chemical Physics ◽

10.1039/d0cp03013a ◽

2020 ◽

Vol 22 (31) ◽

pp. 17620-17631

Author(s):

Xianling Chen ◽

Jing Zhu ◽

Yanlong Luo ◽

Jun Chen ◽

Xiaofeng Ma ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Hydrogen Bonds ◽

Molecular Diffusion ◽

Healing Process ◽

The Self ◽

Dynamics Simulation ◽

Polyurethane Elastomer ◽

Self Healing ◽

Insight Into

The changes in the type and number of hydrogen bonds as well as the microscopic behavior of molecular diffusion in the self-healing process of polyurethane are revealed.

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Study of the Self-Healing Performance of Semi-Flexible Pavement Materials Grouted with Engineered Cementitious Composites Mortar based on a Non-Standard Test

Materials ◽

10.3390/ma12213488 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3488 ◽

Cited By ~ 2

Author(s):

Cai ◽

Huang ◽

Keyword(s):

Flexural Strength ◽

Asphalt Mixture ◽

Temperature Stability ◽

Flexible Pavement ◽

Standard Test ◽

The Self ◽

Cementitious Composites ◽

Self Healing ◽

High Temperature Stability ◽

Engineered Cementitious Composites

Semi-flexible pavement (SFP) materials, with their characteristics of good high temperature stability, strong durability, and lower cost, are suitable for heavy-duty roads, but their cracking problem has hindered the development and popularization of this kind of pavement to a certain extent. In this study, engineered cementitious composites (ECC) were used to form ECC-SFP materials. The self-healing properties of ECC-SFP materials with three kinds of voids of matrix asphalt mixtures were studied. The test results showed that the fluidity and strength of the ECC mortars met the specification requirements when the water–cement ratio was 0.23 and the ECC fiber dosage was 1–2%. The flexural strength of ECC mortar is better than that of ordinary mortar. The higher the ECC fiber dosage, the higher the flexural strength. Increasing the void of the matrix asphalt mixture and the amount of ECC mortar increased the toughness of the ECC-SFP material, which was seen as an increase of the flow value. Curing conditions are key factor affecting the self-healing properties of ECC mortar and ECC-SFP materials. The self-healing effect of materials in 60 °C water is the best. When an ECC fiber dosage of 1% was used, the HImor of ECC mortar and HImix of ECC-SFP material were 27.5% and 24.8%, respectively. With the addition of ECC material, ECC-SFP material achieved a certain degree of self-healing, but this still needs to be further optimized. Studies of grouting process optimization and increasing the ECC fiber dosage are feasible directions to explore in order to improve the self-healing properties of ECC-SFP materials in the future.

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Snow and ice melting properties of self-healing asphalt mixtures with induction heating and microwave heating

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2017.10.050 ◽

2018 ◽

Vol 129 ◽

pp. 871-883 ◽

Cited By ~ 32

Author(s):

Yihan Sun ◽

Shaopeng Wu ◽

Quantao Liu ◽

Jianfu Hu ◽

Yuan Yuan ◽

...

Keyword(s):

Microwave Heating ◽

Induction Heating ◽

Asphalt Mixtures ◽

Self Healing ◽

Ice Melting ◽

Melting Properties ◽

Snow And Ice

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Self-healing of asphalt mixture by microwave and induction heating

Materials & Design ◽

10.1016/j.matdes.2016.05.095 ◽

2016 ◽

Vol 106 ◽

pp. 404-414 ◽

Cited By ~ 105

Author(s):

J. Norambuena-Contreras ◽

A. Garcia

Keyword(s):

Induction Heating ◽

Asphalt Mixture ◽

Self Healing

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Synthesis and Effect of Encapsulating Rejuvenator Fiber on the Performance of Asphalt Mixture

Materials ◽

10.3390/ma12081266 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1266 ◽

Cited By ~ 8

Author(s):

Benan Shu ◽

Shiwen Bao ◽

Shaopeng Wu ◽

Lijie Dong ◽

Chao Li ◽

...

Keyword(s):

Thermal Stability ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

The Self ◽

Self Healing ◽

Excellent Thermal Stability ◽

The Road ◽

Water Sensitivity ◽

Road Performance ◽

Temperature Water

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.

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Self-Healing Analysis of Half-Warm Asphalt Mixes Containing Electric Arc Furnace (EAF) Slag and Reclaimed Asphalt Pavement (RAP) Using a Novel Thermomechanical Healing Treatment

Materials ◽

10.3390/ma13112502 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2502 ◽

Cited By ~ 2

Author(s):

José Manuel Lizárraga ◽

Juan Gallego

Keyword(s):

Mechanical Properties ◽

Microwave Heating ◽

Asphalt Pavement ◽

Electric Arc ◽

Asphalt Mixtures ◽

Self Healing ◽

Arc Furnace ◽

Recycled Asphalt ◽

Indirect Tensile ◽

Eaf Slag

Nowadays, the self-healing of asphalt pavements promoted by microwave radiation heating energy is gaining attention and strength in the scientific community. However, most of these studies are only conceptual and, thus, remain shrouded in uncertainty regarding technology development, economy, and application effect. Therefore, there are several efforts underway to offer more effective assisted healing treatments that are capable of overcoming such uncertainties. This paper aims to assess and quantify the healing performance rates (HR) of half-warm recycled asphalt (HWRA) mixtures containing electric arc furnace (EAF) slag and total recycled asphalt pavement (RAP) rates. To this end, a novel assisted thermomechanical healing treatment (i.e., a recompaction-based technique and microwave heating energy) was put forward to promote the potential healing effect of this treatment on the mechanical properties of the asphalt mixtures. In order to do this, three microwave heating temperatures (25 °C, 60 °C, and 80 °C) and three mechanical recompaction levels (0, 25, and 50 gyrations) were selected. After that, the healing performance rates (%, HR) of the asphalt mixtures were calculated by repeated indirect tensile strength (ITS) and indirect tensile stiffness modulus (ITSM). The results indicated that the 8% EAF slag mixture was found to provide significant microwave heating energy savings by up to 69% compared with the benchmark 100% RAP mixture, and, at the same time, it experienced a remarkable stiffness recovery response of 140% of the initial mechanical properties. These findings encourage greater confidence in promoting this innovative thermomechanical-based healing treatment for in-situ surface course asphalt mixtures of road pavements.

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Microwave Heating of Steel Slag Asphalt Mixture

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.599.193 ◽

2014 ◽

Vol 599 ◽

pp. 193-197 ◽

Cited By ~ 14

Author(s):

Yi Han Sun ◽

Quan Tao Liu ◽

Shao Peng Wu ◽

Fei Shang

Keyword(s):

Thermal Conductivity ◽

Heating Rate ◽

Microwave Heating ◽

Steel Slag ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Self Healing

In this research, the potential of using steel slag asphalt mixture as a self-healing material was investigated by means of microwave heating. The microwave heating rate and thermal conductivity of asphalt mixtures were tested respectively. The result shown that, the heating rate of steel slag asphalt mixtures is approximately two times faster than limestone asphalt mixtures. While its thermal conductivity is slightly lower. It is concluded that microwave heating can be used to promote self-healing of steel slag asphalt mixture.

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Mixture Composition Analysis Of Reclaimed Asphalt Pavement (RAP) As Asphalt Concrete – Wiring Course (AC-WC) Layer Against Marshall Characteristic

Journal of World Conference (JWC) ◽

10.29138/prd.v2i1.134 ◽

2019 ◽

Vol 2 (1) ◽

Author(s):

Wahyu Aunur Rahman Hakim

Keyword(s):

Asphalt Concrete ◽

Asphalt Pavement ◽

Asphalt Mixture ◽

Mixture Composition ◽

Composition Analysis ◽

Reclaimed Asphalt Pavement ◽

Road Maintenance ◽

Reclaimed Asphalt ◽

Natural Aggregate ◽

Marshall Stability

Reclaimed Asphalt Pavement of national roads in East Java Province can be used at AC-WC, AC-BC, AC-Base layers, with a percentage of RAP usage of 20-40%, optimum RAP of 20-30%, asphalt’s content in RAP of 3,78-4.63% (Widayanti, 2018). The composition of the addition for 20% RAP which is originated by Taman-Waru with natural aggregates produces Marshall stability of 830.482 kg and melting / flow of 3.8 mm (Handayani, 2007). Therefore, it is necessary to have research of the analysis about the composition of the Reclaimed Asphalt Pavement (RAP) in the amount of 25%, 30%, 35% as the Asphalt Concrete - Wiring Course (AC-WC) layer against the characteristics of the Marshall. The purpose of this research are 1.) To find out the optimum asphalt content (KAO) in a mixture of AC-WC (Asphalt Concrete - Wearing Course) asphalt and 60/70 Asphalt mixture with the usage of RAP material and natural aggregate in accordance with the General Specifications of Bina Marga 2018 2.) Knowing the effect of the usage of RAP material and natural aggregate for the gradation of asphalt mixture of AC-WC (Asphalt Concrete - Wearing Course) in accordance with the General Specifications of Bina Marga 2018 3.) Knowing the performance of AC-WC asphalt concrete mixture (Asphalt Concrete - Wearing Course) and 60/70 asphalt mixture of RAP material and natural aggregate in terms of Stability and Marshall Quotient values. The research was carried out by the experimental method through laboratory testing. The expected benefit of this research is the discovery for optimizing of the usage recycle materials from road pavement that will be reused during the implementation of road maintenance work and give an alternative of the minimum natural aggregate’s usage. The result of the testing in the laboratory, the mixture of heat asphalt AC-WC with 25% of RAP, had the highest Marshall stability of characteristic for 1309 kg. It’s caused the new materials of the mixture composition has better quality than the mixture of RAP materials, but the additions of RAP composition for 25%, 30%, 35% still can be used as the alternative substitution of nature aggregate, because those are still the Bina Marga’s specification in 2018 of AC-WC mixture.

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