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Increasing rubber content in asphalt mixtures is recognized as a practical approach to consume fast-growing waste tires. The reacted rubber technology using the dry process was developed to address the rubber swelling and poor performance of rubber asphalt mixtures. Although the tire rubber has proved to increase the low-temperature performance, fatigue life, cracking resistance, and rutting resistance of asphalt mixtures, the impacts of high content tire rubber on the mixtures’ internal structures have not been revealed. This study is a preliminary research that utilized the laboratory and numerical simulation approach to investigate the strength, skeleton structures, and stress distribution of the tire rubber asphalt mixtures. The discrete element method (DEM) was employed to establish asphalt mixture models with a high content of tire rubber. New modeling procedures were developed to incorporate coarse aggregate shapes and rubber particles. Indirect tensile strength (ITS) values of specimens with rubber content up to 4.5% by mass were tested in laboratory and simulation. The results from DEM simulation had better consistency than the laboratory results. However, the test results showed that as the rubber content increased, the ITS of asphalt mixtures significantly decreased. Besides, the simulation indicates that the ITS decreased linearly as the percentage air void increased. The specimen ITS value decreased by half as the void ratio reached 15%. Furthermore, the internal structures and stress distribution of specimens with different rubber content were analyzed. The gap gradation proved to have a functional capacity of accommodating fine aggregates and rubber particles, all while forming a coarse aggregate skeleton.
Xiaodong Zhou; Siyu Chen; Dongzhao Jin; Zhanping You. Discrete Element Simulation of the Internal Structures of Asphalt Mixtures with High Content of Tire Rubber. Advances in Transportation Geotechnics IV 2021, 425 -439.
AMA StyleXiaodong Zhou, Siyu Chen, Dongzhao Jin, Zhanping You. Discrete Element Simulation of the Internal Structures of Asphalt Mixtures with High Content of Tire Rubber. Advances in Transportation Geotechnics IV. 2021; ():425-439.
Chicago/Turabian StyleXiaodong Zhou; Siyu Chen; Dongzhao Jin; Zhanping You. 2021. "Discrete Element Simulation of the Internal Structures of Asphalt Mixtures with High Content of Tire Rubber." Advances in Transportation Geotechnics IV , no. : 425-439.
One of the failure mechanisms associated with asphalt paving layers, especially on steel deck bridges, is large permanent deformation, which adversely affects its long-term performance in service. Thus, epoxy resin was introduced in asphalt paving industry to tackle permanent deformation of asphalt mixtures due to its thermosetting nature. In this review, epoxy resin as a dominant component of the epoxy-asphalt composite system was first considered, followed by a discussion on its curing methods and curing mechanism. Furthermore, the physicochemical property and mechanical performance of epoxy asphalt and epoxy asphalt mixture were thoroughly examined. Crosslink density of epoxy asphalt dictates its viscosity and thus the allowable construction time. Phase separation and dispersion of asphalt particles in the epoxy matrix was observed for epoxy-asphalt composite, and it showed superior elastic behavior and deformation resistance capability when compared with conventional asphalt materials. Furthermore, epoxy asphalt mixture exhibited significantly higher compressive strength, much better rutting resistance, and superior durability and water resistance properties. However, its low-temperature cracking resistance was slightly compromised.
Yu Chen; Nabil Hossiney; Xu Yang; Hainian Wang; Zhanping You. Application of Epoxy-Asphalt Composite in Asphalt Paving Industry: A Review with Emphasis on Physicochemical Properties and Pavement Performances. Advances in Materials Science and Engineering 2021, 2021, 1 -35.
AMA StyleYu Chen, Nabil Hossiney, Xu Yang, Hainian Wang, Zhanping You. Application of Epoxy-Asphalt Composite in Asphalt Paving Industry: A Review with Emphasis on Physicochemical Properties and Pavement Performances. Advances in Materials Science and Engineering. 2021; 2021 ():1-35.
Chicago/Turabian StyleYu Chen; Nabil Hossiney; Xu Yang; Hainian Wang; Zhanping You. 2021. "Application of Epoxy-Asphalt Composite in Asphalt Paving Industry: A Review with Emphasis on Physicochemical Properties and Pavement Performances." Advances in Materials Science and Engineering 2021, no. : 1-35.
Transforming waste biomass materials into bio-oils in order to partially substitute petroleum asphalt can reduce environmental pollution and fossil energy consumption and has economic benefits. The characteristics of bio-oils and their utilization as additives of asphalts are the focus of this review. First, physicochemical properties of various bio-oils are characterized. Then, conventional, rheological, and chemical properties of bio-oil modified asphalt binders are synthetically reviewed, as well as road performance of bio-oil modified asphalt mixtures. Finally, performance optimization is discussed for bio-asphalt binders and mixtures. This review indicates that bio-oils are highly complex materials that contain various compounds. Moreover, bio-oils are source-depending materials for which its properties vary with different sources. Most bio-oils have a favorable stimulus upon the low temperature performance of asphalt binders and mixtures but exhibit a negative impact on their high-temperature performance. Moreover, a large amount of oxygen element, oxygen-comprising functional groups, and light components in plant-based bio-oils result in higher sensitivity to ageing of bio-oil modified asphalts. In order to increase the performance of bio-asphalts, most research has been limited to adding additive agents to bio-asphalts; therefore, more reasonable optimization methods need to be proposed. Furthermore, upcoming exploration is also needed to identify reasonable evaluation indicators of bio-oils, modification mechanisms of bio-asphalts, and long-term performance tracking in field applications of bio-asphalts during pavement service life.
Ran Zhang; Zhanping You; Jie Ji; Qingwen Shi; Zhi Suo. A Review of Characteristics of Bio-Oils and Their Utilization as Additives of Asphalts. Molecules 2021, 26, 5049 .
AMA StyleRan Zhang, Zhanping You, Jie Ji, Qingwen Shi, Zhi Suo. A Review of Characteristics of Bio-Oils and Their Utilization as Additives of Asphalts. Molecules. 2021; 26 (16):5049.
Chicago/Turabian StyleRan Zhang; Zhanping You; Jie Ji; Qingwen Shi; Zhi Suo. 2021. "A Review of Characteristics of Bio-Oils and Their Utilization as Additives of Asphalts." Molecules 26, no. 16: 5049.
It has been widely observed that sulfate attack can damage the durability of concrete. This research investigated the mass loss and damage degree of concrete under sodium sulfate attack incorporated with drying-wetting cycles. The impact factors, including water-binder ratio, solution concentration of sodium sulfate, fly ash content, curing time, and drying-wetting cycle system, were observed to influence the sodium sulfate attack by the mass loss rate and damage degree at regular time intervals. Also, the hydrates of sulfate-attacked samples were analyzed using X-ray diffraction. Results indicated that a high water-binder and high-concentration sodium sulfate solution could accelerate the transportation of sulfate ion inside the concrete and the deterioration degree of concrete. Appropriate fly ash and longer curing time can effectively improve the internal pore structure of concrete to reduce the sulfate corrosion damage. The sulfate ion erosion and deterioration degree of the concrete are synchronously intensified along with the increase of the baking-immersing time ratio. The trend of the predicted life for concrete is basically consistent with the damage evolution result, indicating the feasibility of the Weibull distribution model to predict the service life of concrete under sodium sulfate attack incorporated with drying-wetting cycles.
Fang Liu; Zhanping You; Rui Xiong; Xu Yang. Effects of Sodium Sulfate Attack on Concrete Incorporated with Drying-Wetting Cycles. Advances in Civil Engineering 2021, 2021, 1 -12.
AMA StyleFang Liu, Zhanping You, Rui Xiong, Xu Yang. Effects of Sodium Sulfate Attack on Concrete Incorporated with Drying-Wetting Cycles. Advances in Civil Engineering. 2021; 2021 ():1-12.
Chicago/Turabian StyleFang Liu; Zhanping You; Rui Xiong; Xu Yang. 2021. "Effects of Sodium Sulfate Attack on Concrete Incorporated with Drying-Wetting Cycles." Advances in Civil Engineering 2021, no. : 1-12.
In recent decades, polymer-modified asphalt materials have been used in response to increased traffic on the roads. The main objective of this paper is to explore the modification effect of thermoplastics on asphalt binders and investigate the effectiveness of maleic anhydride in improving interfacial adhesion. Three different thermoplastics were used with a dosage of 4 wt%. and a co-reactant maleic anhydride was added with a content of 2 wt% by weight of the binder. The thermoplastics showed a great improvement on high-temperature performance grade (PG) and a slight decrease on low-temperature PG. In addition, the usage of maleic anhydride enhanced the high performance PG on all plastic modified binders. With the addition of maleic anhydride, the binders increased a few degrees of higher temperature, indicating an improvement in compatibility. The compatibility improvement may be related to form a copolymer where maleic anhydride modified with different asphalt components. With the addition of maleic anhydride, the Jnr decreased and the percent recovery increased, which showed a better interaction between plastic and asphalt binders. High-temperature PG results in Unified Performance Tests by incremental Method (UPTiM) were strongly connected with Jnr3.2 in Multiple Stress Creep Recovery test with a power fit trend, where its R2 was 0.97. Based upon results obtained, it can be concluded that the performance of the resulting asphalt can be improved when maleic anhydride was used to treat the added thermoplastics.
Siyu Chen; Tiankai Che; Alaeddin Mohseni; Haleh Azari; Patricia A. Heiden; Zhanping You. Preliminary study of modified asphalt binders with thermoplastics: The Rheology properties and interfacial adhesion between thermoplastics and asphalt binder. Construction and Building Materials 2021, 301, 124373 .
AMA StyleSiyu Chen, Tiankai Che, Alaeddin Mohseni, Haleh Azari, Patricia A. Heiden, Zhanping You. Preliminary study of modified asphalt binders with thermoplastics: The Rheology properties and interfacial adhesion between thermoplastics and asphalt binder. Construction and Building Materials. 2021; 301 ():124373.
Chicago/Turabian StyleSiyu Chen; Tiankai Che; Alaeddin Mohseni; Haleh Azari; Patricia A. Heiden; Zhanping You. 2021. "Preliminary study of modified asphalt binders with thermoplastics: The Rheology properties and interfacial adhesion between thermoplastics and asphalt binder." Construction and Building Materials 301, no. : 124373.
Surface segregation of bituminous mixtures is a criterion of pavement quality and largely affects the characteristics of the pavement. Simple yet effective evaluation of the surface segregation will enable pavement engineers to tailor timely strategies to mitigate the problem. In this paper, a more efficient image processing method with the aid of smartphone imaging was adopted to rate the segregation level of asphalt pavement surface. Twenty-seven asphalt mixture specimens with vast differences were prepared to acquire different surface images using three types of smartphones. A field test section was chosen to validate the practicability. Furthermore, the Fractal Dimensions (FD, DBC-FD) and Percentage of Concave Distribution Area (PCDA) were used to characterize Concave Distribution Characteristics (CDC) of asphalt pavement surface. Texture Depth (TD) and Mean Texture Depth (MTD) were gained through the sand patch method. It was found that it is an encouraging approach to evaluate the surface segregation based on CDC. The image processing technique relying on the selected smartphone type was proposed by the error rate of reliability analysis, which was not more than 3% compared to the other used smartphones. A newly developed indicator called e was presented to stand for PCDA. The coefficient of determination between e, FD, DBC-FD and TD/MTD are respectively 0.7958, 0.7882, and 0.7585. In the field validation, the coefficient of determination between e and TD/MTD reaches to 0.8546. Therefore, it was demonstrated that the proposed image processing method can be a promising approach to rate the segregation of asphalt pavement surface.
Tongtong Wan; Hainian Wang; Ponan Feng; Aboelkasim Diab. Concave distribution characterization of asphalt pavement surface segregation using smartphone and image processing based techniques. Construction and Building Materials 2021, 301, 124111 .
AMA StyleTongtong Wan, Hainian Wang, Ponan Feng, Aboelkasim Diab. Concave distribution characterization of asphalt pavement surface segregation using smartphone and image processing based techniques. Construction and Building Materials. 2021; 301 ():124111.
Chicago/Turabian StyleTongtong Wan; Hainian Wang; Ponan Feng; Aboelkasim Diab. 2021. "Concave distribution characterization of asphalt pavement surface segregation using smartphone and image processing based techniques." Construction and Building Materials 301, no. : 124111.
Cathode-ray-tube (CRT) is the ingredient of glass used in obsolescent televisions or computer monitors. CRT glass contains a considerable amount of heavy metals, and the landfilling of CRT glass is significantly harmful to the environment. In an effort to recycle waste CRT glass instead of landfilling it, recycled CRT glass powders were introduced to asphalt binders as a modifier in this preliminary investigation. The recycled CRT glass was processed to a particle size smaller than 0.075 mm and mixed with asphalt binder (PG 58–28) to produce asphalt mastics with four different concentrations (0, 5, 10, and 15 wt%). The rheological performance was characterized with the rotational viscosity (RV), dynamic shear rheometer (DSR), and multiple stress creep recovery (MSCR) tests. The fatigue performance was evaluated by linear amplitude sweep (LAS) test. Meanwhile, the low-temperature properties were measured by the asphalt binder cracking device (ABCD). The hazard materials leaching test was applied to evaluate the leaching potential of lead content into the external environment due to the high lead content in the modified asphalt. The test results revealed that the increase of CRT glass powder content improved the energy of activation compared with that of virgin binder, as well as the resistance of permanent deformation. Furthermore, the incorporation of CRT glass powder may slightly increase the fatigue life of asphalt because of the improved physicochemical interaction between glass and bitumen. The low-temperature cracking temperature first decreased with the increase of CRT glass powder content and then increased as the CRT content increased further. The leaching test demonstrated that the CRT glass powders incorporated into asphalt binders represented a lower lead leaching content than that of the original CRT glass powder, where the lead leaching amount of CRT glass modified asphalt binder is obviously lower than the specified level of 5 mg/L. Therefore, it is possibly acceptable to recycle CRT glass powders in asphalt binders as an additive as an environmental-friendly recycling method, in which the optimal addition content of CRT glass powders could be up to 10% (wt.).
Dongzhao Jin; Jiaqing Wang; Lingyun You; Dongdong Ge; Chaochao Liu; Hongfu Liu; Zhanping You. Waste cathode-ray-tube glass powder modified asphalt materials: Preparation and characterization. Journal of Cleaner Production 2021, 314, 127949 .
AMA StyleDongzhao Jin, Jiaqing Wang, Lingyun You, Dongdong Ge, Chaochao Liu, Hongfu Liu, Zhanping You. Waste cathode-ray-tube glass powder modified asphalt materials: Preparation and characterization. Journal of Cleaner Production. 2021; 314 ():127949.
Chicago/Turabian StyleDongzhao Jin; Jiaqing Wang; Lingyun You; Dongdong Ge; Chaochao Liu; Hongfu Liu; Zhanping You. 2021. "Waste cathode-ray-tube glass powder modified asphalt materials: Preparation and characterization." Journal of Cleaner Production 314, no. : 127949.
The compatibility between crumb rubber (CR) and asphalt binder plays a key role in the storage stability and rheological performance of rubberized asphalt binder. This review provides a comprehensive overview of characteristics of rubberized asphalt binder, factors influencing compatibility, compatibility evaluation methods, and improvement approaches. Desired compatibility results from the fact that CR is cross-linked with molecules of asphalt binder and evenly distributed in the asphalt binder, forming a homogeneous system. Rheological methods are the most widely used methods for compatibility evaluation. Additionally, the hybrid processing of surface activation treatment of CR and additives-grafting has shown to be a promising method for improving the compatibility of rubberized asphalt binder.
Wenhua Zheng; Hainian Wang; Yu Chen; Jie Ji; Zhanping You; Yuqing Zhang. A review on compatibility between crumb rubber and asphalt binder. Construction and Building Materials 2021, 297, 123820 .
AMA StyleWenhua Zheng, Hainian Wang, Yu Chen, Jie Ji, Zhanping You, Yuqing Zhang. A review on compatibility between crumb rubber and asphalt binder. Construction and Building Materials. 2021; 297 ():123820.
Chicago/Turabian StyleWenhua Zheng; Hainian Wang; Yu Chen; Jie Ji; Zhanping You; Yuqing Zhang. 2021. "A review on compatibility between crumb rubber and asphalt binder." Construction and Building Materials 297, no. : 123820.
To provide a new method for the evaluation of the compaction quality of asphalt mixture, a real-time data acquisition and processing system (RDAPS) for the motion state of aggregate with a small volume and high precision is developed. The system consists of an intelligent aggregate (IA), analysis software and hardware equipment. The performance of the IA was tested by regarding data sensitivity, high-temperature resistance, and mechanical properties. A new evaluation method was proposed for evaluating the compaction quality of AC-25 and SMA-25 asphalt mixtures based on an IA. The results show that the best transmission baud rate for the IA was 9600 bps, and the corresponding signal transmission distance was 380 m. Only one IA was needed to complete the state data collection for the aggregate within the asphalt mixture in a circular area, with the IA layout point as the center of the circle and a radius of 5 m. The IA conducted reliable data transmission up to 200 °C; however, its compressive strength decreased with increasing temperature until reaching stability. Traditional aggregate could be replaced by an IA to withstand external forces and internal load transfer. Embedding an IA into AC-25 or SMA-25 asphalt mixtures did not have a significant impact on the original mechanical properties of the mixture. The effect of the gradation type of the asphalt mixture on the IA motion state was not significant. When the compaction degree met the specification requirements, the motion data of the IA did not reach a stable state, and the interlocking effect between aggregates in the asphalt mixture could be further optimized. An evaluation method is proposed based on the IA for the compaction quality of AC-25 and SMA-25 asphalt mixtures with the compaction degree as the main index and the spatial attitude angle and spatial acceleration of the IA as the auxiliary indexes.
Chen Zhang; Hainian Wang. A New Method for Compaction Quality Evaluation of Asphalt Mixtures with the Intelligent Aggregate (IA). Materials 2021, 14, 2422 .
AMA StyleChen Zhang, Hainian Wang. A New Method for Compaction Quality Evaluation of Asphalt Mixtures with the Intelligent Aggregate (IA). Materials. 2021; 14 (9):2422.
Chicago/Turabian StyleChen Zhang; Hainian Wang. 2021. "A New Method for Compaction Quality Evaluation of Asphalt Mixtures with the Intelligent Aggregate (IA)." Materials 14, no. 9: 2422.
Cold in-place recycling (CIR) asphalt mixtures are an attractive eco-friendly method for rehabilitating asphalt pavement. However, the on-site CIR asphalt mixture generally has a high air void because of the moisture content during construction, and the moisture susceptibility is vital for estimating the road service life. Therefore, the main purpose of this research is to characterize the effect of moisture on the high-temperature and low-temperature performance of a CIR asphalt mixture to predict CIR pavement distress based on a mechanistic–empirical (M-E) pavement design. Moisture conditioning was simulated by the moisture-induced stress tester (MIST). The moisture susceptibility performance of the CIR asphalt mixture (pre-mist and post-mist) was estimated by a dynamic modulus test and a disk-shaped compact tension (DCT) test. In addition, the standard solvent extraction test was used to obtain the reclaimed asphalt pavement (RAP) and CIR asphalt. Asphalt binder performance, including higher temperature and medium temperature performance, was evaluated by dynamic shear rheometer (DSR) equipment and low-temperature properties were estimated by the asphalt binder cracking device (ABCD). Then the predicted pavement distresses were estimated based on the pavement M-E design method. The experimental results revealed that (1) DCT and dynamic modulus tests are sensitive to moisture conditioning. The dynamic modulus decreased by 13% to 43% at various temperatures and frequencies, and the low-temperature cracking energy decreased by 20%. (2) RAP asphalt incorporated with asphalt emulsion decreased the high-temperature rutting resistance but improved the low-temperature anti-cracking and the fatigue life. The M-E design results showed that the RAP incorporated with asphalt emulsion reduced the international roughness index (IRI) and AC bottom-up fatigue predictions, while increasing the total rutting and AC rutting predictions. The moisture damage in the CIR pavement layer also did not significantly affect the predicted distress with low traffic volume. In summary, the implementation of CIR technology in the project improved low-temperature cracking and fatigue performance in the asphalt pavement. Meanwhile, the moisture damage of the CIR asphalt mixture accelerated high-temperature rutting and low-temperature cracking, but it may be acceptable when used for low-volume roads.
Dongzhao Jin; Dongdong Ge; Siyu Chen; Tiankai Che; Hongfu Liu; Lance Malburg; Zhanping You. Cold In-Place Recycling Asphalt Mixtures: Laboratory Performance and Preliminary M-E Design Analysis. Materials 2021, 14, 2036 .
AMA StyleDongzhao Jin, Dongdong Ge, Siyu Chen, Tiankai Che, Hongfu Liu, Lance Malburg, Zhanping You. Cold In-Place Recycling Asphalt Mixtures: Laboratory Performance and Preliminary M-E Design Analysis. Materials. 2021; 14 (8):2036.
Chicago/Turabian StyleDongzhao Jin; Dongdong Ge; Siyu Chen; Tiankai Che; Hongfu Liu; Lance Malburg; Zhanping You. 2021. "Cold In-Place Recycling Asphalt Mixtures: Laboratory Performance and Preliminary M-E Design Analysis." Materials 14, no. 8: 2036.
Concrete mix design and the determination of concrete performance are not merely engineering studies, but also mathematical and statistical endeavors. The study of concrete mechanical properties involves a myriad of factors, including, but not limited to, the amount of each constituent material and its proportion, the type and dosage of chemical additives, and the inclusion of different waste materials. The number of factors and combinations make it difficult, or outright impossible, to formulate an expression of concrete performance through sheer experimentation. Hence, design of experiment has become a part of studies, involving concrete with material addition or replacement. This paper reviewed common design of experimental methods, implemented by past studies, which looked into the analysis of concrete performance. Several analysis methods were employed to optimize data collection and data analysis, such as analysis of variance (ANOVA), regression, Taguchi method, Response Surface Methodology, and Artificial Neural Network. It can be concluded that the use of statistical analysis is helpful for concrete material research, and all the reviewed designs of experimental methods are helpful in simplifying the work and saving time, while providing accurate prediction of concrete mechanical performance.
Beng Chong; Rokiah Othman; Ramadhansyah Putra Jaya; Mohd Mohd Hasan; Andrei Sandu; Marcin Nabiałek; Bartłomiej Jeż; Paweł Pietrusiewicz; Dariusz Kwiatkowski; Przemysław Postawa; Mohd Abdullah. Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review. Materials 2021, 14, 1866 .
AMA StyleBeng Chong, Rokiah Othman, Ramadhansyah Putra Jaya, Mohd Mohd Hasan, Andrei Sandu, Marcin Nabiałek, Bartłomiej Jeż, Paweł Pietrusiewicz, Dariusz Kwiatkowski, Przemysław Postawa, Mohd Abdullah. Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review. Materials. 2021; 14 (8):1866.
Chicago/Turabian StyleBeng Chong; Rokiah Othman; Ramadhansyah Putra Jaya; Mohd Mohd Hasan; Andrei Sandu; Marcin Nabiałek; Bartłomiej Jeż; Paweł Pietrusiewicz; Dariusz Kwiatkowski; Przemysław Postawa; Mohd Abdullah. 2021. "Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review." Materials 14, no. 8: 1866.
The use of reclaimed asphalt pavement (RAP) is a hot research topic in the field of road engineering, as there are still many issues to overcome so as to become standard engineering applications. The diffusion of virgin/aged asphalt binder is a key process to improve RAP performance. In this study, the asphalt binder diffusion models were developed by molecular dynamics (MD) simulation. Two kinds of bio-rejuvenators (BR-1 and BR-5) were chosen to represent the straight-chain and aromatic structures, respectively. The method of relative concentration, radial distribution function (RDF), and microstructure morphology were used to evaluate the effect of bio-rejuvenators on the diffusion process of virgin/aged asphalt binder. The results showed that bio-rejuvenators had a positive effect on the fusion process between virgin and aged asphalt binder. The volume diffusion coefficient based on asphalt binder diffusion models indicated that the bio-rejuvenators accelerated the fusion process between the virgin and asphalt binder. After adding bio-rejuvenators to the aged asphalt binder, the agglomeration intensity in the SARA fractions was reduced to different degrees. Due to the aging of asphalt binder, asphaltenes formed different types of micro-stacking phenomena such as “T-shaped stacking,” “Face to Face stacking,” and “Offset Face to Face stacking.” The bio-rejuvenators of BR-1 and BR-5 exerted different regenerative effects during the diffusion process of aged asphalt binder. For BR-1, the “Pull-Out” and “Intercalation” effect can be observed in the process of asphaltene deagglomeration. “Pull-Out” is the main regenerative effect of BR-5 in aged asphalt binder. A strong electrostatic interaction occurs between BR-5 and PAHs in asphaltenes. Thus, BR-5 achieves the goal of aged asphalt binder regeneration by attracting PAHs.
Heyang Ding; Hainian Wang; Xin Qu; Aikaterini Varveri; Junfeng Gao; Zhanping You. Towards an understanding of diffusion mechanism of bio-rejuvenators in aged asphalt binder through molecular dynamics simulation. Journal of Cleaner Production 2021, 299, 126927 .
AMA StyleHeyang Ding, Hainian Wang, Xin Qu, Aikaterini Varveri, Junfeng Gao, Zhanping You. Towards an understanding of diffusion mechanism of bio-rejuvenators in aged asphalt binder through molecular dynamics simulation. Journal of Cleaner Production. 2021; 299 ():126927.
Chicago/Turabian StyleHeyang Ding; Hainian Wang; Xin Qu; Aikaterini Varveri; Junfeng Gao; Zhanping You. 2021. "Towards an understanding of diffusion mechanism of bio-rejuvenators in aged asphalt binder through molecular dynamics simulation." Journal of Cleaner Production 299, no. : 126927.
This study explored the relationship between air voids and permeability, and investigated the correlation between air void type, coefficient of permeability, mechanical properties, and moisture damage in hot-mix asphalt (HMA). Six asphalt mixtures were prepared with air voids ranging from 4% to 19% in increments of 3%. Major tests, including two air void tests, a penetration test, and a dynamic water scouring test, were conducted to assess the moisture damage by measuring and comparing the difference in air voids and permeability before and after the dynamic water scouring. A compressive test was conducted to evaluate the residual strength of HMA with different porosities. Results indicated that the effective voids and coefficient of permeability had a strong correlation. There was an obvious increase of effective voids and permeability for specimens with air voids from 10% to 13% after dynamic water scouring tests. In terms of compressive strength, specimens with air voids from 7% to 13% had greater strength loss and deformation than other specimens, indicating that moisture damage occurred and developed rapidly in asphalt mixtures within a certain porosity range.
Tiankai Che; Baofeng Pan; Dong Sha; Yuanteng Zhang; Zhanping You. Relationship between Air Voids and Permeability: Effect on Water Scouring Resistance in HMA. Journal of Materials in Civil Engineering 2021, 33, 04021022 .
AMA StyleTiankai Che, Baofeng Pan, Dong Sha, Yuanteng Zhang, Zhanping You. Relationship between Air Voids and Permeability: Effect on Water Scouring Resistance in HMA. Journal of Materials in Civil Engineering. 2021; 33 (4):04021022.
Chicago/Turabian StyleTiankai Che; Baofeng Pan; Dong Sha; Yuanteng Zhang; Zhanping You. 2021. "Relationship between Air Voids and Permeability: Effect on Water Scouring Resistance in HMA." Journal of Materials in Civil Engineering 33, no. 4: 04021022.
The compatibility between asphalt and nanosilica (nano-SiO2) is critical to determine the performance of nano-SiO2–modified asphalt. However, a comprehensive understanding of the compatibility behavior and mechanism of asphalt components and nano-SiO2 in the modified asphalt is still limited. In this study, the compatibility was revealed through molecular dynamics (MD) simulation. Virgin asphalt, nano-SiO2–modified asphalt, and oxidation aged asphalt models produced with the COMPASS force field; meanwhile, the proposed models were validated by comparisons with reference data. The compatibility of asphalt and nano-SiO2 was analyzed by solubility and the Flory–Huggins parameters and interaction energy. Results show that the solubility parameters decreased with the increase of system temperature while increased with the asphalt’s oxidation level increase. Meanwhile, the compatibility of the asphaltene, resin, and aromatic components in asphalt is better than the compatibility with saturates, which may be due to saturates being volatile; however, the compatibility of the nano-SiO2 and saturates is much better than those with asphaltene, resin, and aromatic components. The incorporation of nano-SiO2 alleviates the volatilization of saturates. The present results provide insights into the understanding of the compatibility behavior and mechanism of nano-SiO2 and asphalt components.
Zhengwu Long; Sijia Zhou; Shaoting Jiang; Wenbo Ma; Yanhuai Ding; Lingyun You; Xianqiong Tang; Fu Xu. Revealing compatibility mechanism of nanosilica in asphalt through molecular dynamics simulation. Journal of Molecular Modeling 2021, 27, 1 -14.
AMA StyleZhengwu Long, Sijia Zhou, Shaoting Jiang, Wenbo Ma, Yanhuai Ding, Lingyun You, Xianqiong Tang, Fu Xu. Revealing compatibility mechanism of nanosilica in asphalt through molecular dynamics simulation. Journal of Molecular Modeling. 2021; 27 (3):1-14.
Chicago/Turabian StyleZhengwu Long; Sijia Zhou; Shaoting Jiang; Wenbo Ma; Yanhuai Ding; Lingyun You; Xianqiong Tang; Fu Xu. 2021. "Revealing compatibility mechanism of nanosilica in asphalt through molecular dynamics simulation." Journal of Molecular Modeling 27, no. 3: 1-14.
The objective of this paper is to review the current characterization and evaluation methods and introduce emerging technologies of aggregate morphologies in asphalt mixture through conventional tests and imaging techniques that would be possibly applied to analyze and evaluate the morphological features of particles. The current evaluating-characterizing method is defined as a procedure that has been shown by experience or research to obtain satisfying results, that is established or proposed as a standard suitable for general application. This review first identified the methods based on laboratory tests to characterize and evaluate the morphologies of the aggregate particle. Then, an attempt was made to study the existing methodologies from different points of view, accompanied by extensive comparisons on three categories of imaging techniques-early imaging techniques, dynamic imaging techniques, and static imaging techniques to facilitate further research studies. Additionally, the evaluation parameters of aggregate morphologies based on image technologies were represented. Finally, a comparative evaluation between different conventional testing methods and different imaging techniques through basic tools, application conditions, advantages, and disadvantages were conducted. This review concluded with some recommendations and conclusions in terms of morphological characterization and evaluation of aggregates in the asphalt mixture to materials selection during the mixture design and construction.
Fangyuan Gong; Yu Liu; Zhanping You; Xiaodong Zhou. Characterization and evaluation of morphological features for aggregate in asphalt mixture: A review. Construction and Building Materials 2020, 273, 121989 .
AMA StyleFangyuan Gong, Yu Liu, Zhanping You, Xiaodong Zhou. Characterization and evaluation of morphological features for aggregate in asphalt mixture: A review. Construction and Building Materials. 2020; 273 ():121989.
Chicago/Turabian StyleFangyuan Gong; Yu Liu; Zhanping You; Xiaodong Zhou. 2020. "Characterization and evaluation of morphological features for aggregate in asphalt mixture: A review." Construction and Building Materials 273, no. : 121989.
The clump-based discrete element model is one of the asphalt mixture simulation methods, which has the potential to not only predict mixture performance but also simulate particle movement during compaction, transporting, and other situations. However, modelling of asphalt sand mortar in this method remains to be a problem due to computing capacity. Larger-sized balls (generally 2.0–2.36 mm) were usually used to model the smaller particles and asphalt binder, but this replacement may result in the mixture’s unrealistic volumetric features. More specifically, replacing original elements with equal volume but larger size particles will increase in buck volume and then different particle contacting states. The major objective of this research is to provide a solution to the dilemma situation through an improved equivalent model of the smaller particles and asphalt binders. The key parameter of the equivalent model is the diameter reduction factor (DRF), which was proposed in this research to minimize the effects of asphalt mortar’s particle replacement modelling. To determine DRF, the DEM-based analysis was conducted to evaluate several mixture features, including element overlap ratio, ball-wall contact number, and the average wall stress. Through this study, it was observed that when the original glued ball diameters are ranging from 2.00 mm and 2.36 mm, the diameter reduction factor changes from 0.82 to 0.86 for AC mixtures and 0.80 to 0.84 for SMA mixtures. The modelling method presented in this research is suitable not only for asphalt mixtures but also for the other particulate mix with multisize particles.
Yu Liu; Peifeng Su; Miaomiao Li; Hui Yao; Junfu Liu; Mei Xu; Xiaodong Zhou; Zhanping You. How to Achieve Efficiency and Accuracy in Discrete Element Simulation of Asphalt Mixture: A DRF-Based Equivalent Model for Asphalt Sand Mortar. Advances in Civil Engineering 2020, 2020, 1 -10.
AMA StyleYu Liu, Peifeng Su, Miaomiao Li, Hui Yao, Junfu Liu, Mei Xu, Xiaodong Zhou, Zhanping You. How to Achieve Efficiency and Accuracy in Discrete Element Simulation of Asphalt Mixture: A DRF-Based Equivalent Model for Asphalt Sand Mortar. Advances in Civil Engineering. 2020; 2020 ():1-10.
Chicago/Turabian StyleYu Liu; Peifeng Su; Miaomiao Li; Hui Yao; Junfu Liu; Mei Xu; Xiaodong Zhou; Zhanping You. 2020. "How to Achieve Efficiency and Accuracy in Discrete Element Simulation of Asphalt Mixture: A DRF-Based Equivalent Model for Asphalt Sand Mortar." Advances in Civil Engineering 2020, no. : 1-10.
The aim of this research is using a waste wood–based bio-oil as the modifier of petroleum asphalt and analyzing its modification mechanism. The four components, infrared spectrum, and molecular weight distribution analysis were performed to investigate the chemical performance of control binder and bioasphalts. A conventional petroleum asphalt PG 64-22 was employed as the control binder. The bio-oil with addition of 10%, 15%, and 25% by weight was used to prepare bioasphalts (BMA). Meanwhile, the Gas Chromatograph Mass Spectrometer (GC-MS) and oven heating tests were conducted to explore the chemical compounds and their approximate contents in bio-oil. Results demonstrated that the bio-oil significantly changed the contents of chemical components in asphalt binder by decreasing the contents of saturates and asphaltenes and increasing the aromatics and resins contents. The modification of petroleum asphalt by bio-oil is not only a physical mixing but also a chemical process. Some chemical reactions were deduced between the PG 64-22 and bio-oil based on the infrared spectrum analysis. The added bio-oil converted some large molecules into small molecules. There are various chemical compounds in the bio-oil. Higher content of aromatic compounds and many lightweight compounds can explain the softer quality of bioasphalt and its inferior high temperature properties in comparison to petroleum asphalt.
Ran Zhang; Jie Ji; Zhanping You; Hainian Wang. Modification Mechanism of Using Waste Wood–Based Bio-Oil to Modify Petroleum Asphalt. Journal of Materials in Civil Engineering 2020, 32, 04020375 .
AMA StyleRan Zhang, Jie Ji, Zhanping You, Hainian Wang. Modification Mechanism of Using Waste Wood–Based Bio-Oil to Modify Petroleum Asphalt. Journal of Materials in Civil Engineering. 2020; 32 (12):04020375.
Chicago/Turabian StyleRan Zhang; Jie Ji; Zhanping You; Hainian Wang. 2020. "Modification Mechanism of Using Waste Wood–Based Bio-Oil to Modify Petroleum Asphalt." Journal of Materials in Civil Engineering 32, no. 12: 04020375.
The road pavement is a typical three-dimensional (3D) multilayered half-space medium, which consists of the surface courses, base courses, and soil subgrade/foundation. It is critical to understand the dynamic response of the road pavement under vehicular loads for improving structural design efficiency. The actual vehicular loads can be simulated as a harmonic moving load. In general, there are several methods to analyze the dynamic response of the multilayered half-space medium under harmonic moving loads, such as the boundary element method (BEM) and the finite-element method (FEM). However, the previously mentioned methods might face some unavoidable problems, for example, the numerical overflow, when the thickness of the medium is thicker, which causes the wrong result or long computing time. Therefore, the objective of this study is to develop a precise solution to solve the dynamic response of the 3D multilayered half-space medium under a harmonic moving load. In this study, a new type of 3D spectral element method (SEM) was developed and applied to the dynamic response analysis. Details of the mathematical derivation, implementation, and verification were demonstrated in the current paper. Subsequent numerical results, based on a layered road pavement structure constructed on a soil foundation, indicated that both the load speed and the frequency, the damping ratio of the structural materials, and the interlayer condition significantly impacted on the dynamic response of the structure under vehicular loads.
Lingyun You; Kezhen Yan; Jianhong Man; Tingwei Shi. 3D Spectral Element Solution of Multilayered Half-Space Medium with Harmonic Moving Load: Effect of Layer, Interlayer, and Loading Properties on Dynamic Response of Medium. International Journal of Geomechanics 2020, 20, 04020227 .
AMA StyleLingyun You, Kezhen Yan, Jianhong Man, Tingwei Shi. 3D Spectral Element Solution of Multilayered Half-Space Medium with Harmonic Moving Load: Effect of Layer, Interlayer, and Loading Properties on Dynamic Response of Medium. International Journal of Geomechanics. 2020; 20 (12):04020227.
Chicago/Turabian StyleLingyun You; Kezhen Yan; Jianhong Man; Tingwei Shi. 2020. "3D Spectral Element Solution of Multilayered Half-Space Medium with Harmonic Moving Load: Effect of Layer, Interlayer, and Loading Properties on Dynamic Response of Medium." International Journal of Geomechanics 20, no. 12: 04020227.
The authors wish to make the following correction to this paper
Chengdong Xia; Songtao Lv; Lingyun You; Dong Chen; Yipeng Li; Jianlong Zheng. Correction: Xia, C.; et al. Unified Strength Model of Asphalt Mixture under Various Loading Modes. Materials 2019, 12, 889. Materials 2020, 13, 5393 .
AMA StyleChengdong Xia, Songtao Lv, Lingyun You, Dong Chen, Yipeng Li, Jianlong Zheng. Correction: Xia, C.; et al. Unified Strength Model of Asphalt Mixture under Various Loading Modes. Materials 2019, 12, 889. Materials. 2020; 13 (23):5393.
Chicago/Turabian StyleChengdong Xia; Songtao Lv; Lingyun You; Dong Chen; Yipeng Li; Jianlong Zheng. 2020. "Correction: Xia, C.; et al. Unified Strength Model of Asphalt Mixture under Various Loading Modes. Materials 2019, 12, 889." Materials 13, no. 23: 5393.
The purpose of this study is to compare the performance of rubber-modified asphalt mixtures prepared with incorporation of latex and crumb rubber. The service characteristics of the rubber-modified asphalt mixtures were evaluated using workability index and compaction energy index to determine the ease of placing, handling, and compacting of the asphalt mixture. The engineering properties of the asphalt mixtures were also evaluated in terms of indirect tensile strength (ITS), resilient modulus, permanent deformation, moisture susceptibility, and the Leutner shear test. Crumb rubber and latex were separately used as modifiers in this study. The percentage of crumb rubber and latex used were 5% and 10%, while organo silane additive was added at a rate of 0.1%, all by the weight of asphalt binder. Through the evaluation, the modified asphalt mixture required comparable energy for compaction through the assessment of compaction energy index (CEI) as compared to the control asphalt mixture. Based on the results of performance test, it can be concluded that the crumb rubber-modified asphalt mixture showed a better performance than the latex-modified asphalt mixture in terms of fracture resistance, permanent deformation, resilient modulus, shear resistance, and moisture resistance. Overall, the rubberised asphalt mixture has better engineering performance properties that can prolong the lifespan of the flexible pavement compared to the conventional asphalt mixture.
Sharvin Poovaneshvaran; Lim Wee Zheng; Mohd Rosli Mohd Hasan; Xu Yang; Aboelkasim Diab. Workability, compactibility and engineering properties of rubber-modified asphalt mixtures prepared via wet process. International Journal of Pavement Research and Technology 2020, 14, 560 -569.
AMA StyleSharvin Poovaneshvaran, Lim Wee Zheng, Mohd Rosli Mohd Hasan, Xu Yang, Aboelkasim Diab. Workability, compactibility and engineering properties of rubber-modified asphalt mixtures prepared via wet process. International Journal of Pavement Research and Technology. 2020; 14 (5):560-569.
Chicago/Turabian StyleSharvin Poovaneshvaran; Lim Wee Zheng; Mohd Rosli Mohd Hasan; Xu Yang; Aboelkasim Diab. 2020. "Workability, compactibility and engineering properties of rubber-modified asphalt mixtures prepared via wet process." International Journal of Pavement Research and Technology 14, no. 5: 560-569.