Types Of Asphalt Mixtures Research Articles

Investigating the Effects of Chopped Basalt Fiber on the Performance of Porous Asphalt Mixture

Porous asphalt mixture is a type of asphalt mixture with good drainage. However, it has poor tensile strength performance and durability. Chopped basalt fibers (CBF) have been proved to be an effective additive to improve the mechanical and fatigue performance of asphalt mixtures, but little attention has been paid on porous asphalt mixture. This paper examined the effect of chopped basalt fibers with different lengths (nonfiber, 3 mm, 6 mm, 9 mm, and 12 mm) and contents (3% and 4%) on the performance of the porous asphalt mixture. A series of tests were conducted to figure out the optimum fiber length and content, including draindown test, cantabro abrasion test, freeze-thaw split tensile test, wheel tracking test, low-temperature cracking resistance test, and four-point bending beam test. Thereafter, indirect tensile tests at different temperatures were conducted to investigate the tensile strength properties of porous asphalt mixtures with optimum fiber length and content. Besides, the macroscopic and microscopic morphology of fracture sections of the samples after indirect tensile tests were studied by using a single-lens reflex (SLR) camera and scanning electron microscopy (SEM) so as to further explore the reinforced mechanism of chopped basalt fibers. The results show that the addition of chopped basalt fibers can generally improve the performance of porous asphalt mixture since chopped basalt fibers form a three-dimensional network structure in the porous asphalt mixture.

KARAKTERISTIK CAMPURAN AC-WC MENGGUNAKAN MATERIAL RECLAIMED ASPHALT PAVEMENT DENGAN TAMBAHAN ASPAL PEN. 60/70 YANG DISUBSTITUSI STYROFOAM

Reuse of reclaimed asphalt pavement material (RAP) is an alternative which applicated for potential enough on the roughness of the road. RAP material can be reused by adding the asphalt and the new aggregate according of the mixture composition so that it is expected will be obtained the quality as planned. One of the efforts made in improving the quality of asphalt mixture RAP material is using a modified asphalt with additional material, such as styrofoam. The use of styrofoam into the asphalt is expected to improve the technical properties of a mixture. The purpose of this research is to know the comparative characteristics of hot mix asphalt (asphalt concrete) type AC-WC that uses RAP material with additional asphalt pen. 60/70 and asphalt pen. 60/70 substitution in the styrofoam by 8%, 10% and 12% against the weight of asphalt based on levels of asphalt left on the material. The initial stages of this study is to conduct an examination of the physical properties of RAP material, then manufacturing a specimen with variations of the addition of asphalt and aggregate new levels based on the job mix diesign (JMD) Bina Marga Aceh (2013). Based on research results, parameter values marshall on all types of asphalt mixture with new aggregate as well as RAP materials and the use of 100% asphalt pen. 60/70 additional or different types of asphalt on OAC has fulfilled the technical specifications defined by the Bina Marga (2014). Best stability values obtained on asphalt mixture using RAP material with additional asphalt pen. 60/70 with 12% styrofoam substitution on OAC JMD Bina Marga Aceh, that amounted to 3,308.72 kg, the lowest value stability retrieved on asphalt mixture using a new aggregate based on the results of Department of Bina Marga Aceh on OAC i.e. of 983.94 kg.

The effect of ENDB specimen geometry on mode I fracture toughness and fracture energy of HMA and SMA mixtures at low temperatures

Cracking is one of the major deterioration mechanisms of asphalt pavements at low temperatures. Over the last decades, fracture mechanics has been used as a tool to investigate this phenomenon. For this purpose, two related measures namely, fracture toughness and to some extent, fracture energy are used to investigate the performance of asphalt mixtures at low ambient temperature conditions. Various types of laboratory specimens have been used in previous research studies to investigate the fracture toughness and fracture energy of Hot Mix Asphalt (HMA) mixtures. Recently, a new specimen called ENDB (Edge Notched Disk Bend) has been proposed by researchers which features additional advantages over the widely used Semi-Circular Bend (SCB) specimen. However, very little research has been conducted on the appropriate geometry of this specimen in fracture tests. This article presents the results of a study on the effect of ENDB specimen geometry on the fracture toughness and fracture energy of two widely used asphalt mixture types namely, HMA and Stone Mastic Asphalt (SMA) at low temperatures. For this purpose, a set of 54 ENDB specimens was produced in three thicknesses of 30, 50 and 70 mm, three crack depth ratios of 0.2, 0.4 and 0.6 for two types of HMA and SMA mixture types. The nominal maximum size of aggregates used in the experiments was 9.5 mm and the specimens were tested under mode I fracture toughness at −15 °C. The results of the fracture tests in these conditions indicated that the thickness of the specimens has a significant effect on the fracture toughness of both HMA and SMA mixtures. The results showed that under the studied conditions, it would be appropriate to use ENDB specimens with at least 50 mm and preferably 70 mm thickness. The results also indicated that a crack depth ratio of 0.4 would be appropriate for the HMA and SMA specimens. However, when a study is only concerned with the SMA mixture type and specimens with 70 mm thickness are used, a crack depth ratio of 0.2 would be more appropriate.

Mechanical characteristics of shear strength ratio used for moisture susceptibility evaluation of asphalt mixtures

ABSTRACT One of the widely used parameters in evaluating moisture susceptibility of asphalt mixtures is tensile strength ratio (TSR). From a mechanical point of view, TSR is only appropriate at the bottom of asphalt concrete (AC) layer where tensile stress is predominant since near the surface or in the middle of AC layer shear stress is the major driving force to create moisture damage. Therefore, a better parameter that can describe moisture susceptibility for the entire AC layer is needed. In this study, the potential of shear strength ratio (SSR) in evaluating moisture susceptibility at different AC depths is attempted. The mechanical relationship among the SSR, TSR, cohesion and indirect tensile (IDT) strength has been studied wherein it was found that the SSR can be mechanically represented by the TSR and cohesion. In addition, the SSR values are determined from mechanistic analyses using the shear properties obtained from laboratory tests conducted for three types of asphalt mixtures. The results show that the SSR values are significantly varying along the depth of AC layer, while the TSR values are constant. Therefore, SSR could be a good alternative parameter in evaluating the moisture susceptibility of asphalt mixtures at different AC depths.

Noise reduction characteristics of asphalt pavement based on indoor simulation tests

Abstract Low noise asphalt pavement mitigates the impact of traffic noise on the ecological environment and surrounding population to a certain extent. To explore the noise reduction characteristics of different asphalt pavements, an indoor simulation device for pavement noise reduction is developed in this paper, based on the principle of pavement noise reduction. The device simulates the process of noise reflection and interference on the surface and inside of the pavement, which consumes the sound energy to achieve the noise reduction effect. The mechanical performance of six different types of asphalt mixtures is first tested. The noise reduction performance of the asphalt mixtures is then studied using the self-made noise testing device and Kundt’s tube method to verify the accuracy of the device. The influence of surface texture on pavement noise is also analyzed, and test results show that the six types of asphalt mixtures used in this study all meet mechanical performance requirements. A strong correlation is also observed between the noise testing device and the traditional Kundt’s tube method. The noise testing device is found to accurately measure the noise reduction characteristics of asphalt mixtures. For noise of different sound pressure levels, the same type of asphalt mixture displays different noise reduction capabilities. The better the noise reduction performance, the lower the sensitivity to sound wave changes, and the more stable the noise reduction effect. Excessive air void content does not significantly improve the pavement noise reduction performance, and it is recommended that the pavement air void content is maintained within the range of 17%–24%. The density of the asphalt mixture is found to be negatively correlated with the noise reduction performance, while the air void content and the mean texture depth is positively correlated with noise reduction. The results of grey relational analysis show that air void content is the most important factor affecting the noise reduction characteristics of asphalt pavement, followed by mean texture depth. Aggregate particle size is also found to exert a significant influence on noise reduction characteristics, and the influence degree of 9.5 mm particles is found to be the greatest, with 1.18 mm and 2.36 mm particles also showing a high degree of influence. Reasonable control of aggregate particle size should therefore be carried out in the design of low noise asphalt pavement.

Study on the Influence of Asphalt Content on Fatigue Life of Asphalt Mixture

The fatigue failure form of asphalt pavement is not reflected in the design index of asphalt mixture proportion when determining the optimum asphalt content in the existing asphalt mixture proportion design. In order to solve the problem, the effect of different asphalt content on the fatigue life of three types of asphalt mixtures was studied by indirect tensile fatigue test.The results show that: (1) the splitting strength of asphalt mixture decreases with the increase of asphalt content; (2) the fatigue life of asphalt mixture increases first and then decreases with the increase of asphalt content; (3) the order of sensitivity of fatigue life of three types of asphalt mixture to asphalt content is: AC-5 > STRATA > ATB-25.Some useful suggestions are put forward for the design of asphalt mixture with good fatigue resistance.

Study on influence factors of asphalt mixtures pavement blistering on Portland cement concrete bridge deck

ABSTRACT This paper aims to discuss the blister properties on Portland cement concrete bridge deck pavement. The deformation characteristic and mechanism of blister are investigated quantitatively by an automatically developed pressurised blister simulation tests and Digital speckle correlation method (DSCM). Two different types of asphalt mixtures (SMA-13 and AC-13) and three different types of asphalt waterproof bonding materials (SBS modified bitumen, rubber bitumen, SBS modified emulsified bitumen) were studied in this paper. The air void of asphalt mixture, test temperature and material types were analysed to explore the influence on the blister deformation. In addition, the initial surface absorption test (ISAT) is used to quantitatively assess the influence of air void. The results indicate the air void of asphalt mixture and the test temperature have different influences on the blister damage performance. The blister failure mode has a direct relationship with air void. For the same asphalt waterproof adhesive layer, SMA-13 asphalt mixture is better than AC-13 asphalt mixture in the resistance of blister deformation.

Microwave crack healing on conventional and modified asphalt mixtures with different additives: an experimental approach

Self-healing asphalt by increasing bitumen temperature using microwave radiation is an effective technique for crack-healing on asphalt mixtures. Normally, these types of asphalt mixtures contain metal additives that promote microwave heating. However, results from the literature suggest that crack-heling would be possible without additives. If this is possible, existing asphalt pavements could be healed by microwave heating. The objective of this research is to evaluate the crack-healing capabilities of conventional asphalt mixtures without metal additives. With this purpose, the authors studied and compared the crack-healing capabilities of conventional asphalt mixtures without metal additives with modified mixtures containing steel fibre, metal shavings, and Silicon Carbide, the last being a novel ceramic material for the crack-healing of asphalt mixtures by microwaves. The authors conducted three-point bending tests on semi-circular asphalt samples to calculate the flexural strength of asphalt. Results of the research showed that the effect of additives that promote microwave heating on the crack-healing of mixtures was a small reduction of the average healing ratio. Additionally, it was found that the effect of additives that promote microwave heating on the surface temperature of samples was either a small increase or small decrease, similar to the effect observed in the healing of mixtures. X-Ray computed tomography results showed that the virgin aggregates used contained metals, which explains the heating and good crack-healing of the reference mixtures. Overall, results of crack-healing tests indicate that asphalt mixtures with aggregates that naturally heat with microwave radiation could be crack-healed without the addition of additives to promote microwave heating.

Laboratory Study of the Use of Additional Reacted and Activated Rubber (RAR) Materials on Asphalt Concrete-Wearing Course (AC-WC) Mix

<em>The development of infrastructure in Indonesia was increasing. The government focuses on boosting infrastructure development to create long-term economic growth. Therefore, a qualified infrastructure was a standard of an advanced rapidly economy. One of them is under construction was road and toll road infrastructure. As a result of the development was the occurrence of the increasing volume of vehicles on the road. Due to this resulting in an increased load reposition and also increased vehicle load on the road, it was then combined with a wet tropical climate or humid warm areas in Indonesia that have high rainfall and temperatures that can reach 38<sup>o</sup>C, resulting in structural damage such as cracks, rutting, stripping, and pothole. Performance from pavement also declined faster than the estimated plan. Roads in Indonesia mostly use the type of concrete asphalt mixture. Characteristics for concrete asphalt prioritize stability. In fact, the most important thing was the stability and durability of the road. Various ways can be done to overcome the road damage and acquire the ideal characteristics such as the use of added materials to Hot Mix Asphalt. To improve the performance of pavement characteristics, the use of added materials was expected to overcome problems that are affected by temperature, weather, increased vehicle volume, and increased traffic load. The added materials are to enhance Reacted and Activated Rubber (RAR) which was a developed crumb rubber to increase durability and keep the level of road pavement stability.</em>

Salt-dissolved regularity of the self-ice-melting pavement under rainfall

The salt in the Self-ice-melting pavement can dissolve gradually during rainfall, which will shorten its snow-melting life. The purpose of this study was to analyze the law of salt dissolution with the improved Hamburg wheel-track device under the action of rain, load-rain coupling and humidity-temperature coupling. The experimental results showed that the amount of salt dissolved under the action of rain was significantly less than that under the action of load-rain coupling, and the amount of salt dissolved was very small under the action of humidity-temperature coupling, so its action can be neglected. Based on the studies above, the influence on the salt dissolved of factors such as rainfall intensity, anti-icing filler dosage, void volume, temperature, and the type of asphalt mixture was analyzed by the method of gray relational analysis under the action of load-rain coupling, after which a prediction model of the amount of salt dissolved was established with the regression analysis software 1stopt. The results showed that the correlation coefficient of the developed prediction model was 0.961, and the improved Hamburg wheel-track device can be used to evaluate the effect of rainfall on salt dissolution.

Mechanical characteristics of tensile strength ratio method compared to other parameters used for moisture susceptibility evaluation of asphalt mixtures

Abstract In this study, mechanical characteristics of tensile strength ratio (TSR) were evaluated by comparing it to other methods in evaluating moisture sensitivity of asphalt mixtures. Twenty types of asphalt mixtures with and without anti-stripping additives were prepared and tested in the laboratory. Uniaxial compressive strength (UCS) and indirect tensile (IDT) testing were conducted to determine the mixture's tensile strength ratio and cohesion ratio (CR). Determining TSR alone was found to be insufficient when evaluating moisture resistance. There is a need to consider both TSR and wet IDT strength to properly evaluate moisture behavior of asphalt mixtures. Moreover, it was found that the cohesion and the IDT strength have a good relation in which the minimum condition of the slope, must be met. However, it was observed that β values change depending on material type and temperature. Hence, there is a need to evaluate these β values for varying material and testing temperature. In addition, it was found that the TSR and CR results are highly correlated with an average difference of 1.5%. Furthermore, other tests such as Marshall stability and dynamic immersion were also conducted. It was found that Marshall stability ratio (MSR) and Marshall stability to flow ratio (MSFR) values are less sensitive to moisture effect when measuring moisture resistance compared to TSR values. Finally, the 48 h testing result of the dynamic immersion test showed better correlation with TSR values.

Implement the Laplace transform to convert viscoelastic functions of asphalt mixtures

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 R2 > 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.

An Evaluation of Moisture Damage Resistance of Asphalt Concrete based on Dynamic Creep Characteristics

The performance of asphalt concrete is severely influenced by moisture. The presence of moisture in asphalt pavement substantially reduces its designed service lifetime. Currently, the indirect tensile strength test with constant loading rate is employed to estimate the moisture damage potential to an asphalt mixture. This evaluation method is empirical in nature and, therefore, suitable for only empirically designed asphalt pavements. However, speculation exists in that the conventional testing method may inappropriately simulate actual field conditions. Therefore, this research aims to evaluate the moisture damage potential to asphalt concrete under cyclic loading using the dynamic creep testing platform. The dynamic creep test provides the flow number, which represents the number of loading cycles at the failure point of the asphalt mixture. Three different types of asphalt mixtures commonly used in Western Australia were investigated in this research. The dynamic creep test provided more reasonable evaluation results of potential moisture damage than the conventional method. The tensile strength ratio of all mixtures in this research were greater than 80%, which is the conventional design criteria. On the other hand, the dynamic creep test reveals that flow number ratio of two mixtures dropped below 80%. The flow number ratio of 14 mm mixture was 58%, while 56% was obtained from 20 mm mixture. However, high uncertainty in the dynamic creep test results was observed, due to the interpretation technique. In conclusion, based on the research findings, the dynamic creep test can be used as a complementary test of the stripping potential in asphalt concrete.

Field and laboratory measurement of albedo and heat transfer for pavement materials

Albedo is an important indicator of the radiation reflectance of pavement surface and commonly measured using the field albedometer. In this study, factors affecting the field measurement of albedo including solar radiation intensity, incident angle and surrounding conditions were investigated. A new albedometer for laboratory testing of albedo and internal temperature at different depths in compacted asphalt mixture/Portland cement concrete (PCC) slabs was developed to overcome the negative effects of field measurements. Laboratory measurements of albedo were performed on three types of asphalt mixture (e.g. AC-13, SMA-13 and OGFC-13) and PCC with different surface textures using the developed albedometer. Three types of coating materials were prepared by mixing base material of transparent epoxy glue and the filler of Nano-TiO2, Micro-TiO2 and Nano-ZnO, respectively. The albedo and internal temperature of asphalt mixtures with coating materials were also measured and compared to those without coating materials. Results show that the developed laboratory albedometer can synchronously measure the accurate albedo and internal temperature of pavement materials. The albedo of three types of asphalt mixtures have a range of 5.46%–6.11%, while the albedo of PCC with different surface textures ranges from 22.8% to 26.4%. The gradation of asphalt mixture has little impact on the albedo. Rougher PCC surface reflect less solar radiation and produce a higher internal temperature. The filler of Micro-TiO2 in pavement coating has the better reflectance than Nano-TiO2 and Nano-ZnO.

Influence of angularity and roughness of coarse aggregates on asphalt mixture performance

The damage of asphalt mixture occurs in asphalt-aggregate interphase. The strength was directly associated with the overall performance of mixture. In this paper, Marshall test was applied to investigate the high-temperature stability. The high-temperature stability, water stability and low-temperature performance of five types of asphalt mixtures were tested through Marshall test, and the correlation between road performance dynamic stability, freeze-thaw split strength ratio, and low-temperature flexural tensile strength and average angular coefficient of coarse aggregate was studied. Moreover, the correlations of asphalt-aggregate interphase strength to the pavement performance index of asphalt mixture were also established.

Analysis of a Methodology for Torsional Test under Normal Stress and Shear Performance for Asphalt Mixtures

Insufficient shear performance in an asphalt mixture is a primary reason for rutting deformation and pavement surface longitudinal cracking. Thus, it is important to choose a suitable shear test method to evaluate shear performance in an asphalt mixture. Current testing methods mainly evaluate the bonding strength between asphalt layers, and the current shear test method for an asphalt mixture is disadvantaged by high equipment cost and complicated procedures. Our study proposes a torsional test method under normal stress condition, and evaluation was done for four types of asphalt mixture under different temperature conditions. Through the mechanical analysis, the calculation formulas for shear strength and shear parameters (cohesion and internal friction angle) for the torsional test under a normal stress condition were obtained. Testing results were also obtained for shear strength, shear modulus, and cohesion and internal friction angle of the asphalt mixtures. Experimental testing indicated that the method was able to provide repeatable results for the shear resistance of asphalt mixtures at different temperatures and also reflected the difference in shear performance of the various asphalt mixtures and the influence of temperature on shear performance. The failure mode of the specimen was the appearance of an oblique crack of about 45° from the vertical axis after the specimen was destroyed, which accorded with shear failure characteristics. A shear fatigue model was obtained considering different shear stress levels. The torsional test method under normal stress formed a compression‐shear action on the specimen by applying torque and normal stress and was used to evaluate the shear performance of the asphalt mixtures.

Long‐Term Performance and Deicing Effect of Sustained‐Release Snow Melting Asphalt Mixture

To accelerate snow and ice melting, traditional chloride‐based salts are spreaded on asphalt pavement surface, causing serious environmental pollution and infrastructure corrosion. For sustained‐release snow melting asphalt mixture, the snow melting agent of Mafilon is directly added to asphalt mixture by replacing partial mineral powder to develop a new type of functional asphalt mixture. In this paper, through the Marshall test, immersion Marshall test, rutting test, trabecular bending test, and Cantabro test, the effects of Mafilon addition on asphalt pavement performance is systematically analysed. Meanwhile, salt precipitation rate is measured by conductimetry to estimate effective deicing period of the pavement. Finally, a new experimental device is designed to quantitatively evaluate snow melting effect of sustained‐release snow melting asphalt pavement. The experimental results show that replacing 70% of the mineral powder with Mafilon by volume can achieve satisfactory snow melting effect without affecting usability of asphalt pavement.

Effect of the recycled rubber grain in the rutting of an asphalt mixture type MD-12

Currently in Colombia, a lot of used tires are generated which have not been provided with proper handling,for this reason, environmental problems are significant, therefore, there is a need to look for alternatives that encourage the reuse of waste from various recyclable materials and thus incorporate them into the production cycle, obtaining as a major benefit a reduction in the environmental impact caused by this type of waste. According to the above, the investigation analyzed the effect of the recycled rubber grain added by dry process, in the rutting of an asphaltic mixture type MD-12, through the plastic deformation resistance test standardized by the Instituto Nacional de Vías INVIAS 2013. The analysis was carried out using the Marshall methodology with the design of an asphalt mixture conventional MD-12 and three MD-12 asphalt mixtures with variations in the addition of GCR, the preliminary designs and verification of each of the asphalt mixes as established in the general construction specifications of the Instituto de Desarrollo Urbano IDU 2011, obtaining the respective working formula of each asphalt mixture. Obtaining favorable behaviors in asphalt mixtures with addition of 0.5% of GCR in which there are decreases of up to 5.3% in the rutting, with respect to the asphaltic mixture of reference, also it highlights the improvements that the asphalt mixture presented in terms of resistance to plastic deformation or rutting, before the addition of rubber grain recycled by dry process, for this reason it is recommended to use it in asphalt mixtures type MD-12 as part of the fine aggregate and thus obtain a greater efficiency from the mechanical point of view, as well as the improvements in the useful life of the pavement and the mitigation of the environmental impacts generated by the mishandling of tires out of use in the country.

Estimation of energy consumption on the tire-pavement interaction for asphalt mixtures with different surface properties using data mining techniques

The energy or fuel consumption of the millions of vehicles that daily operate in road pavements has a significant economic and environmental impact on the use phase of road infrastructures regarding their life cycle analysis. Therefore, new solutions should be studied to reduce the vehicles energy consumption, namely due to the tire-pavement interaction, and contribute towards the sustainable development. This study aims at estimating the energy consumption due to the rolling resistance of tires moving over pavements with distinct surface characteristics. Thus, different types of asphalt mixtures were used in the surface course to determine the main parameters influencing the energy consumption. A laboratory scale prototype was developed explicitly for this evaluation. Data mining techniques were used to analyze the experimental results due to the complex correlation between the data collected during the tests, providing meaningful results. In particular, the artificial neural network allowed to obtain models with excellent capacity to estimate energy consumption. A sensitive analysis was carried out with a five input parameter model, which showed that the main parameters controlling the energy consumption are the vehicle speed and the mean texture depth.

Moisture seepage in asphalt mixture using X-ray imaging technology

Understanding moisture flow in asphalt mixtures is the first step in analyzing moisture-induced damage caused by moisture in pavements. However, the precise quantities of the dynamic movements of wetting fronts and their relationship with the internal structures of asphalt mixtures are yet to be determined. The aims of this study are (1) to quantify the dynamic movements of wetting fronts in asphalt mixtures with X-ray computed tomography (X-ray CT) and (2) to investigate the effects of internal structures of asphalt structures on seepage characteristics. In this study, purified water and three types of asphalt mixtures were used as liquid and pavement materials, respectively. We initially applied sensitivity analysis to determine optimal experimental condition and then performed X-ray CT to balance scanning time and measurement precision in the capture of microscale moisture distribution. The characteristics of moisture seepage, including wetting front, seepage velocity, and initial inertial region, were quantified by tracing the flow at different moments. At a fixed infiltration rate, all the local seepage velocities decreased in power function over time, suggesting the existence of unsteady flow during the seepage. The initial inertia of water droplet had a stronger influence on the vertical migration than in the horizontal migration. This result indicated that the hemispherical shape transport pattern shifted to a trapezoidal shape with the increase of penetration time. Water droplets were easily broken, and water was prone to spread in horizontal direction owing to the decrease in void size, thereby consequently resulting in the directional distribution of the initial inertial region. These findings contribute to the understanding of dynamic moisture movement on the micro-scale of asphalt mixtures and provide an effective opportunity to reveal the evolutionary path of moisture-induced damage in asphalt pavement.