Cracking Of Asphalt Mixtures Research Articles

Fiber Showdown: A Comparative Analysis of Glass vs. Polypropylene Fibers in Hot-Mix Asphalt Fracture Resistance

Cracks in asphalt mixtures compromise the structural integrity of roads, increase maintenance costs, and shorten pavement lifespan. These cracks allow for water infiltration, accelerating pavement deterioration and jeopardizing vehicle safety. This research aims to evaluate the impact of synthetic fibers, specifically glass fiber (GF) and polypropylene fiber (PPF), on the crack resistance of Hot-Mix Asphalt (HMA). An optimal asphalt binder content of 5% was used in all sample designs. Using the dry mixing technique, GFs and PPFs were incorporated into the HMA at dosages of 0.50%, 1.00%, and 1.50% by weight of the aggregate. The effects of these fibers on the mechanical fracture properties of the HMA were assessed using Semi-Circular Bending (SCB), Indirect Tensile Asphalt Cracking Tests (IDEAL-CTs), and Three-Point Bending (3-PB) tests. This study focused on fracture parameters such as fracture work, peak load, fracture energy, and crack indices, including the Flexibility Index (FI) and Crack Resistance Index (CRI). The results from the SCB and IDEAL-CT tests showed that increasing GF content from 0.5% to 1.5% significantly enhances the flexibility and crack resistance of HMA, with FI, CRI, and CT Index values increasing by 247.5%, 55%, and 101.35%, respectively. Conversely, increasing PPF content increases the mixture’s stiffness and reduces its crack resistance. The PP-1 mixture exhibited higher FI and CT Index values, with increases of 31.1% and 10%, respectively, compared to the PP-0.5 mixture, based on SCB and IDEAL-CT test results. The SCB, IDEAL-CT, and 3-PB test results concluded that fibers significantly influence the fracture properties of bituminous mixtures, with a 1% reinforcement dosage of both PPFs and GFs being optimal for enhancing performance across various applications.

Development of a cyclic semi-circular bending test protocol to characterize fatigue cracking of asphalt mixture at intermediate temperature

The Semi-Circular Bending (SCB) test has been traditionally conducted in a monotonic loading and displacement-controlled mode at intermediate temperature to assess the fatigue crack resistance of asphalt mixtures. However, fatigue damage is essentially deterioration in material integrity as a result of repeated loading. The SCB monotonic loading does not realistically reflect the traffic loading repetition. This may have limitation on mechanism of the fatigue cracking in asphalt mixture. This study aims to develop a cyclic SCB test protocol to characterize the fatigue cracking of asphalt mixtures. Digital Image Correlation (DIC) was utilized to identify crack length associated with the number of loading cycles applied. A full factorial design was conducted for the optimization of testing parameters of the cyclic SCB test, including three levels of notch depth and loading frequency. Two indicators including the number of cycles to failure and Paris’ Law coefficients were used to characterize the fatigue cracking resistance of asphalt mixture. The proposed test protocol of cyclic SCB was validated by three asphalt mixtures of good, medium, and poor cracking performance. The critical strain energy release rate Jc of three mixtures is also measured by the monotonic SCB test for studying the relationship between Jc and Paris’ Law coefficients. The results indicate that Paris’ Law coefficients have relatively low variance compared to the number of cycles to failure and are independent of notch depth and loading frequency. The optimal testing parameter combination of 25 mm notch depth and 10 Hz loading frequency was recommended in perspective of test variance and test practicability. The Paris Law coefficient n ranking was consistent with the one of fatigue cracking resistance of asphalt mixtures evaluated.

Evaluation of Low- and Intermediate-Temperature Cracking Performance of Fiber-Reinforced Asphalt Mixtures

This study was conducted to assess the impact of aramid fiber reinforcement on the fatigue and thermal cracking performance of asphalt mixtures at intermediate and low temperatures, respectively. The study also involved evaluating the experimental consistency and ranking fiber-reinforced asphalt mixtures (FRAMs) based on their performance. One aggregate (diabase stone), one binder type (PG 76-22), and two combinations of aramid fibers, added at different dosages, were used to produce three FRAMs. These fibers included polyolefin/aramid (PFA) fibers at 0.05% dosage by mix weight and Sasobit-coated aramid (SCA) fibers at 0.01% and 0.02% dosages. An unreinforced (control) mix was also produced without any reinforcement. All mixtures were produced at a batch plant by keeping their binder content constant (at 5.5%). The manufacturer recommended dry and wet mixing times were used for better fiber distribution and represent actual mixing conditions. The laboratory performance of plant-produced FRAMs was assessed to characterize the low- and intermediate-temperature cracking performance. The indirect tension asphalt cracking test, semi-circular bend test, three-point bending beam tests, and uniaxial fatigue tests were performed at intermediate temperature; the disk shape compact tension test and thermal stress restrained specimen test tests were performed at low temperature. Fibers were successful at improving the fatigue cracking of asphalt mixtures based on intermediate-temperature testing results. In addition, fiber reinforcement, regardless of dosage and combination, showed improvements in low-temperature (thermal) cracking performance. Furthermore, based on ranking analysis for selected performance indicators from each experiment, the SCA 0.02% reinforced mix on average showed the highest cracking resistance.

Investigating the effect of fundamental properties of materials on the mechanisms of thermal cracking of asphalt mixtures

In most of tests and models to evaluate the thermal cracking of asphalt mixture, the consideration of different elements within the asphalt mixture has been neglected to provide a corrective solution. Accordingly, in this research, the evaluation of the mechanisms of thermal cracking involved assessing the impact of surface free energy (SFE) parameters and other fundamental properties of bitumen and aggregate. These parameters included the adhesion and cohesion free energy, the ratio of the base element to the acid element of the aggregate SFE (RBA), the creep stiffness of bitumen, the rate of changes in creep stiffness (m-value), and specific surface area (SSA) of aggregate. To this end, Wilhelmy plate (WP) test, universal sorption device (USD) test, the bending beam rheometer (BBR) test and the pull-off test were performed. In the following, models were presented to evaluate the effect of mentioned parameters as independent variables on the mechanisms of thermal cracking using an artificial neural network (ANN). The sensitivity analysis of the Artificial Neural Network (ANN) model revealed that in the status of adhesive failure, the cohesion free energy and m-value did not affect the Pull-off adhesion strength. On the other hand, the adhesion free energy, RBA, and the SSA were directly proportional and the creep stiffness was inversely proportional to the Pull-off adhesion strength. Also, in the status of cohesive failure, the adhesion free energy, the RBA, and the SSA did not affect the Pull-off cohesion strength. On the other hand, the cohesion free energy and m-value were directly proportional and the creep stiffness was inversely proportional to the Pull-off cohesion strength.

Surfactants effects on the self-healing properties of asphalt mixtures in a water environment

Under a certain temperature, cracks in asphalt mixtures can heal themselves, but water in the cracks will reduce the self-healing performance of the asphalt mixture. In this study, surfactants were added to asphalt mixtures. In the presence of water, the characteristics of amphiphilic surfactants are used to promote the adsorption between asphalt and aggregates; In this paper, the ability of surfactants to promote the formation of adsorption of asphalt on the crystal surface is verified using a combination of molecular simulations and macroscopic experiments. Molecular simulation results show that the adsorption energies of asphalt and surfactants, surfactants and silica, and asphalt and silica are all negative. Adsorption can occur between the three interfaces, and the surfactants effectively pulls the asphalt molecules onto the silica molecules, achieving adsorption similar to that between asphalt organic polymers and crystals. Macroscopic experiments show that in asphalt mixtures with active agents added, the active agent can be adsorbed on the surface of the aggregate, part of the asphalt is adsorbed on the surface of the active agent, and part is directly adsorbed on the gravel. Some asphalt is also adsorbed on the aggregate under the action of pure water, but the total adsorption capacity is lower than that of asphalt mixtures containing surfactants.

Evaluation of thermal cracking probability for asphalt concretes with high percentage of RAP

The paper presents determination of the probability of thermal cracking of asphalt mixtures with different reclaimed asphalt pavement (RAP) content on the basis of laboratory tests and analytical evaluation using thermal stress development method. Probability was evaluated taking into consideration: the type and gradation of the mixture and the quality and content of RAP. Thermal stresses were determined using two models: elastic and viscoelastic. Addition of RAP decreases the low-temperature properties of all the tested asphalt mixtures. In the case of wearing and binder courses, addition of 20% of RAP increases the cracking temperature by around 5–6 °C.

Micro-structural Behavior and Macro-experimental Analysis of Asphalt Mixture Cracking at Low Temperature Based on Molecular Simulation

Micro-structural Behavior and Macro-experimental Analysis of Asphalt Mixture Cracking at Low Temperature Based on Molecular Simulation

Characteristics and properties of asphalt mortar containing FO filler

As a preventive maintenance method, microwave self-healing is an effective method for early repairing small cracks in asphalt mixture, reducing maintenance costs and prolonging service life. However, asphalt mixtures containing aggregate-type wave-absorbing agents have a common problem of uneven heating. Asphalt mixture was prepared by partially replacing the limestone filler with ferroferric oxide (Fe3O4, FO), and the healing performance under microwave heating was studied. The rheological properties of asphalt mortars with FO and the fluidity of conventional asphalt mortars were studied by dynamic shear rheometer (DSR). Then, the magnetostatic properties and electromagnetic parameters of FO fillers were analyzed by vibrating sample magnetometer (VSM) and vector network analyzer (VNA). Finally, the semicircular bending (SCB) samples were studied by the breaking-microwave healing experiment. The results show that FO fillers have obvious ferromagnetism, and they mainly rely on magnetic loss for energy conversion. FO is beneficial to the improvement of high temperature rheological properties of asphalt mortar but not to low temperature rheological parameters; the replacement ratio of FO to limestone filler should not exceed 50%. The flow healing behavior of asphalt mortar is greatly affected by temperature, which is the fundamental reason for the self-healing of asphalt mixture. The heating efficiency of the asphalt mixture containing FO filler is significantly improved under microwave irradiation; the FO filler has a slightly negative effect on the initial strength of SCB samples but can significantly improve the healing rate after microwave.

Characteristic analysis of cement grouted asphalt mixture cracking based on acoustic emission

Cracking is one of the main diseases of cement grouted asphalt mixture (CGAM). This paper aims to disclose the whole process failure characteristics of CGAM under different loads. Three types of tests under acoustic emission monitoring were designed to observe the performance of CGAM under indirect tension, bending tension and compression. Stone matrix asphalt (SMA) was used as the control group. The results show that the failure process of CGAM can be divided into three stages. Large damage will be produced in one or more short periods. The cracking of cement mesh is one of the main factors to form cracks in CGAM, and its brittleness leads to the proportion of macro cracks of CGAM in each stage being greater than that of SMA. The proportion of shear failure of CGAM is higher than that of SMA, so more attention should be paid to its shear resistance in material design.

Self-healing of low-temperature cracks in asphalt mixture under different fracture modes

This research aims to investigate the self-healing of low-temperature cracks in asphalt mixture using semicircular bending tests at different modes of fracture. In this research, samples are fabricated with a 12.5 mm nominal size aggregate and PG58-22 binder. All aged and unaged asphalt samples are subjected to 10 cooling cycles. Also, the resting time between cooling cycles is applied to self-healed samples. The results show that cooling cycles significantly reduce the fracture energy and applying the resting time increases the healing, cracking resistance, and balanced cracking indices. In addition, the most effective of self-healing is observed at fracture mode II.

Effect of carbon nanotubes on fatigue cracking of asphalt mixtures modified by styrene-ethylene/propylene-styrene

ABSTRACT Fatigue cracking is a significant cause of failure in flexible pavements at moderate temperatures. Neat bitumen cannot properly perform at all temperatures and environmental conditions due to the increasing traffic volume. Consequently, this study examined the simultaneous usage of carbon nanotubes (CNTs) and the styrene-ethylene/propylene-styrene (SEPS) polymer as bitumen modifiers. The linear amplitude sweep (LAS) test and surface free energy (SFE) theory were used to determine the rheological characteristics and thermodynamic parameters of neat and modified bitumens, respectively. Using the SEPS nanocomposite up to 6% increased the fatigue life and moisture damage resistance of the asphalt mixtures by improving thermodynamic parameters such as adhesive free energy in dry and wet conditions. According to the LAS results, the modified bitumen outperformed the neat bitumen in terms of fatigue life under different strain levels. The fatigue life of the asphalt mixtures also decreased as the temperature increased from 10 to 20°C. However, for the mixtures containing the SEPS nanocomposite, the reduction in fatigue life was less noticeable due to the lower temperature sensitivity of the modified bitumen. The mixtures containing 6% SEPS nanocomposite demonstrated the highest performance.

The effect of reclaimed asphalt pavement (RAP) content and source on the return on investment (ROI)

ABSTRACT This study evaluated the impact of using different contents and sources of Reclaimed Asphalt Pavement (RAP) on the bottom-up fatigue cracking of asphalt mixtures and the return on investment (ROI). Two RAP sources were used that primarily provided a significant difference in RAP binder Performance Grade (PG): Source A was a PG 76-22 while Source B was a PG 94-10. Bottom-up fatigue cracking was predicted using Level 1 of the AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software. The ROI was then evaluated using FHWA RealCost. To increase the accuracies of the predictions, volumetric properties and blended binder properties were calculated based on the amount of RAP binder that actively blended with the virgin binder. The accuracies were also increased by determining the AASHTOWare PMED fatigue strength coefficients, k f 1 , k f 2 , and k f 3 , using flexural bending beam fatigue tests rather than using the global defaults provided by this software. In conclusion, the ROI of the six RAP mixtures based on bottom-up fatigue cracking was found to be affected by both RAP content and RAP source, and because of the effect of RAP source, it could not be generalised that using either a higher or lower RAP content will always provide a higher ROI.

Low and intermediate temperatures fracture behavior of amorphous poly alpha olefin (APAO)-modified hot mix asphalt subjected to constant and variable temperatures

Low-temperature cracks (LTC) and intermediate-temperature cracks (ITC) are two important types of cracks in asphalt mixtures that cause damage to pavements and incur high maintenance costs on roads. On the other hand, temperature cycles, in addition to the traffic load on the asphalt mixtures, increase the possibility of structural failures. Therefore, it is necessary to study the solutions to deal with and control this type of cracking using appropriate methods. In this study, an attempt was made to evaluate the effect of amorphous poly alpha olefin (APAO) additive on the LTC and ITC behavior of Hot Mix Aspahlt (HMA) under loading conditions of modes I and II under constant temperature (CT) and variable temperature (VT) cycles. For this purpose, two geometries called symmetric specimen SCB (contains a vertical crack with an angle of 90°) and classical-modified specimen SCB-2 (contains an angled crack with an angle of 35°) were selected to simulate the loading conditions of mode I, as well as two geometries called modified specimen SCB-1 (contains a vertical crack with a 90-degree angle) and modified specimen SCB-2 (contains a vertical crack with a 90-degree angle) were selected to simulate mode II loading conditions. A total of four HMA mixtures were made, including one mixture without additives and three mixtures containing 3, 6, and 9 % APAO additives. Next, in order to simulate and match the road conditions with the laboratory samples, CT and VT conditions were applied to all samples. At temperatures of ± 15 °C, two fracture resistance indices called fracture toughness (KIC and KIIC) and fracture energy (GF) were studied to investigate the fracture behavior of HMA mixtures. Also, two other fracture indices, namely the Tensile Stiffness Index (TSI) and the Tensile Strength (TS), which represent the fracture behavior of the HMA mixture before the peak load, were evaluated. Finally, the flexibility of the mixtures was evaluated using brittleness indices such as the Flexibility Index (FI), Cracking Resistance Index (CRI), and Toughness Index (TI). The results showed that the fracture toughness and fracture energy of the HMA mixture containing 9 and 6 % APAO increased in mode I and II loading conditions under both CT and VT cycles compared to the base mixture. At temperatures of ± 15 °C, from the point of view of the fracture toughness index, the potential for creating angular cracks, and from the point of view of the fracture energy index, the full fracture potential of the mixture containing vertical cracks was higher (under CT and VT cycles). On the other hand, the reduction of the flexibility of the mixtures containing APAO percentages was concluded using FI, CRI, and TI indices. Also, the results showed that the addition of 3, 6, and 9 % of APAO additive to the HMA mixture increased the maximum preload indices, namely TSI and TS, and as a result, increased resistance to elastic deformation.

Relationship among air void microstructural characteristics, stiffness, and fatigue of asphalt concrete mixtures

It is a common sense that the air void content significantly affects the field performance of asphalt mixtures. Thus, this parameter is a key mix design criterion and is also adopted as a quality assurance/control tool. Even though the air voids play a notorious role in the behaviour of asphalt mixtures, the knowledge about their microstructural characteristics is still limited. To overcome this limitation, advanced techniques such as the X-ray micro-computed tomography technology may be pursued as an alternative. This paper uses X-ray micro-computed tomography to identify microstructural parameters of air voids within asphalt mixtures, i.e. distribution, content, type, size, and degree of anisotropy. These microstructural characteristics are compared to the stiffness and the resistance to fatigue cracking of asphalt mixtures. The findings suggest that the air void distribution is strongly correlated with the mixture stiffness and fatigue behaviour, and that the air void heterogeneity should be avoided.

A comparative study of the effects of calcium alginate capsules on self-healing properties of base and SBS modified asphalt mixtures

Calcium alginate capsules can gradually release healing agent and heal cracks in asphalt mixtures under vehicle loading. However, the current research is focusing on how calcium alginate capsules affect the self-healing abilities of base asphalt mixtures. It is still unclear whether calcium alginate capsules can be utilized to rejuvenate and heal SBS modified asphalt mixture. Through a three-point bending (3 PB)-cyclic compression loading-3 PB test, the effects of calcium alginate capsules on the self-healing characteristics of base and SBS modified asphalt mixtures were examined and compared in this study. Fourier transform infrared spectroscopy (FTIR) and dynamic shear rheometer (DSR) tests were conducted on extracted asphalt binders to study the release behaviors of the capsules within different asphalt mixtures and their regeneration effects on the asphalt binders. The findings demonstrate that under cyclic compression loading, calcium alginate capsules can greatly enhance the strength recovery ratios of base and SBS modified asphalt concretes. The capsules in SBS modified asphalt concrete released the oil more rapidly than in base asphalt concrete probably due to the higher mixing temperature. Both the base and SBS modified asphalts can be rejuvenated by the oil released from the capsules. However, SBS modified asphalt concrete containing the capsules showed lower strength recovery ratios than base asphalt concrete due to lower flow ability of SBS modified asphalt and incapacity of the capsules to repair the broken SBS polymer network.

Prospective application of coal gangue as filler in fracture-healing behavior of asphalt mixture

Coal gangue powder, which is an environmental waste, was used as filler to investigate its facilitation effect on microwave heating and self-healing of asphalt mixture. In this work, two types of fillers named coal gangue powder (CGP) and coal gangue ash (CGA) were utilized to prepare various mixtures to replace conventional limestone powder (LMP) by six rates of 0%, 15%, 35%, 50%, 75%, and 100%. Firstly, the micromorphology and composition properties of different fillers were performed by scanning electron microscopy (SEM) and X-ray fluorescence (XRF) test. Secondly, the semi-circular bending (SCB) test was conducted to analyze the low-temperature fracture performance of mixtures. Then, the microwave heating capacity and behaviors of fillers and mixtures were studied on the basis of infrared thermography imaging. Ultimately, the mixtures healing efficiency was evaluated with five fracture-healing-fracture cycles and the electromagnetic parameters were determined via a microwave network vector analyzer. Test results reveal that mixtures with appropriate CGA and CGP filler proportion both possess better microwave heating effect, while the excessive dosage of CGA or CGP filler will result in mixtures’ uneven surface temperature distribution. It is found that 50% CGA or 50% CGP can be a prospective substitution because this rate not only obtains excellent healing effectiveness at 60-s microwave heating but also improve the low-temperature crack resistance of mixture. Moreover, the higher dielectric and magnetic losses of CGA and CGP provide an explanation for promoting microwave heating. The aforementioned results show that coal gangue powder waste has prominent application in asphalt mixture cracking and self-healing and thus improve its utilization in this method.

Effects of Geometry and Loading Mode on the Stress State in Asphalt Mixture Cracking Tests.

Currently, a variety of asphalt mixture cracking characterization tests are available as screening tools for the better selection of high-quality raw materials and also for the optimization of mixture design for different applications. However, for a same evaluation index, using different sample geometries and loading modes might lead to obtaining different values, which prevents the application of the evaluation index as a fundamental parameter in pavement design. In this paper, the effects of geometry and loading mode on the stress state in the experimental characterization of asphalt mixture cracking were discussed using numerical simulation. The results showed that applying thermally-induced load in restrained uniaxial test configuration should be considered when performing an asphalt mixture cracking test. Compared with direct tensile configuration, compressive stress clearly existed in other common test configurations, which may prevent the initiation and propagation of cracks. Moreover, it was revealed that nonuniform stress state exists in the dog-bone geometry, which makes it possible to know the failure plane in advance and place gauges at the failure plane for measuring fundamental deformation-related properties.

Cracking features of asphalt mixtures under induced heating-healing

This research presents effects of induced heating-healing process on fracture properties and life extension of asphalt mixtures. Induced heating-healing technique is an innovative technique to repair damages and heal cracks in asphalt mixtures, implementing an external electromagnetic field to raise temperature of asphalt mixture. Temperature rising results in melting and flowing of asphalt binder between crack edges, healing cracks, and recovering internal strength of asphalt mixture lost during service life. Previous researchers considered different criteria to quantify induced healing efficiency in asphalt concrete, resulting in substantial differences. Nevertheless, conclusions presented by previous researchers are not comparable due to different materials, heating, healing, and testing conditions. Hence, a further study is needed to identify induced healing effectiveness based on asphalt mixtures form different binder grades. In this study, activated carbon modified and unmodified asphalt binders were utilized to prepare asphalt mixtures. Then, a cyclic heating-healing scenario under semi-circular bending (SCB) test was conducted at intermediate and low temperatures. Values of the fracture criteria (i.e., peak load, stress intensity factor, stiffness, strain energy, critical strain energy release rate, and fracture energy) were quantified at each cycle. Besides, extensions of fatigue and thermal fatigue lives obtained via induced healing process were characterized. Comparing results of modified and unmodified mixtures indicates that activated carbon significantly improves efficacy of induced healing. Additionally, induced healing process leads to different effects on different crack features. Moreover, induced healing efficiencies obtained based on fatigue and thermal fatigue extensions are approximately similar to that of peak load criterion. This study indicates that to evaluate effects of induced heating-healing process on improvement of different mechanical behaviors in asphalt mixtures over service life, corresponding crack property (criteria) needs to be considered.

Development of an analysis tool for deterministic and probabilistic viscoelastic continuum damage approach

Pavement industry concerns have been increasing in the past decades towards fatigue cracking due to its negative impact on asphalt pavement performance. Therefore, several studies were conducted to model and characterize asphalt mixture fatigue life and number of cycles to failure (Nf) to achieve the designer’s goal ensuring the asphalt pavement serviceability, durability and to reduce the cost. Viscoelastic Continuum Damage (VECD) approach with incorporating probabilistic analysis (P-VECD) was proposed by several researchers to characterize the fatigue cracking of asphalt mixtures reliably. Although the probabilistic VECD studies attract great attention for characterizing the fatigue crack of asphalt mixtures, the VECD-Nf model random variables (RVs) are defined by using many arbitrary assumptions. Furthermore, the proposed approaches are very complicated, which added computation complexity to the VECD mode. Therefore, the prediction of asphalt mixtures’ fatigue life is needed in a reliable and simple process. This study focuses on developing a user-friendly analysis tool that determines the Nf following the VECD approach with incorporating probabilistic analysis. To achieve this goal, the proper distribution function for each RV in the VECD-Nf model is defined, a simple analysis tool is developed using MATLAB App Designer, and previous studies data for Hot-Mix Asphalt (HMA) and Fine Warm-Mix Asphalt (F-WMA) mixtures are re-analyzed using the developed P-VECD analysis tool. By using the P-VECD analysis tool, deterministic VECD analysis, probabilistic VECD analysis, and the prediction of the fatigue life of asphalt mixtures will be possible for technicians and engineers in the asphalt community.

Pure mode I and pure mode II fracture resistance of modified hot mix asphalt at low and intermediate temperatures

AbstractAngular cracks are one of the types of cracks in asphalt mixtures that can be created due to the location of coarse aggregates as well as the weakness of the soft asphalt matrix (SAM). In this study, pure mode I was modeled to simulate the fracture behavior of hot mix asphalt (HMA) mixture containing angular cracks using the extended finite element method (XFEM). To improve HMA performance, calcium lignosulfonates (CL) additive and polyester fiber (PE), which were both environmentally and economically justifiable, were used. Numerical and experimental results showed that the proposed samples in both pure mode I (angular crack) and pure mode II (vertical crack) were able to model the fracture behavior of HMA; therefore, it can be used as suitable samples to study the pure mode crack deformation of HMA at low and intermediate temperatures. Also, the presence of coarse aggregate in the ligament section of the samples turned out to be an important factor in increasing fracture energy, fracture toughness, and reducing brittleness.