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Cracking is a common fault in asphalt and concrete pavements, which causes water damage and further defects if not repaired in timely fashion. Conventional pavement crack sealing methods based on machines and manual operations are generally subjective, labour-intensive, risky, and inefficient. A laboratory prototype of an automatic pavement crack sealing platform is proposed in this paper, which uses a modified three-dimensional (3D) printer and computer vision. A modified 3D printer based on fused deposition modelling (FDM) was combined with an image capturing platform, an image processing algorithm and a path planning method to form the automated pavement crack sealing platform, which can automatically detect pavement cracks and seal them with bitumen emulsion sealant. Specimens of concrete pavement slabs with cracks were produced in the laboratory to test the proposed method, and the cracks were then detected and sealed by the proposed platform. The results show that 3D printing is an effective method for automated pavement crack sealing, which is recommended in the field of automatic road maintenance and repair.
Jingwei Liu; Xu Yang; Xin Wang; Jian Wei Yam. A laboratory prototype of automatic pavement crack sealing based on a modified 3D printer. International Journal of Pavement Engineering 2021, 1 -12.
AMA StyleJingwei Liu, Xu Yang, Xin Wang, Jian Wei Yam. A laboratory prototype of automatic pavement crack sealing based on a modified 3D printer. International Journal of Pavement Engineering. 2021; ():1-12.
Chicago/Turabian StyleJingwei Liu; Xu Yang; Xin Wang; Jian Wei Yam. 2021. "A laboratory prototype of automatic pavement crack sealing based on a modified 3D printer." International Journal of Pavement Engineering , no. : 1-12.
To address the severe distresses of asphalt pavement, a new type of pavement maintenance treatment, porous ultra-thin overlay (PUTO) with small particle size was proposed. The PUTO has a thickness of 1.5–2.5 cm and a large void ratio of 18–25%. As a newly asphalt mixture, the structure characteristics differ from poor traditional pavement. Therefore, it is necessary to investigate the fabrication schemes in laboratory and on-site, respectively. In this study, the optimal fabrication schemes, including compaction temperature and number of blows of PUTO were determined based on Cantabro test and volumetric parameters. Then, the corresponding relationship between laboratory and on-site compaction work was then established based on the energy equivalent principle. On this basis, the numbers of on-site rolling passes and the combination method were calculated. The results show that increased compaction temperature and number of blows reduce the height and enhance the compaction of the Marshall sample. With the same temperature and number of blows, the raveling resistance of coarse gradation, Pavement Asphalt Concrete-1 (PAC-1) is better than that of fine gradation, Pavement Asphalt Concrete-2 (PAC-2), and the increased asphalt viscosity significantly improves the raveling resistance of the asphalt mixture. To ensure the scattering resistance and volumetric characteristic, the initial compaction temperature of the PAC-1 and PAC-2 should not be lower than 150 °C and 165 °C, respectively. Then, the laboratory compaction work and on-site compaction work were calculated and converted based on the principle of energy equivalence. Consequently, the on-site compaction combination of rolling machines for four asphalt mixtures was determined. According to the volumetric parameters, the paving test section proved that the construction temperature and the on-site rolling combination determined by laboratory tests are reasonable, and ultra-thin overlay has good structural stability, drainage, and skid resistance.
Jiahao Tian; Sang Luo; Ziming Liu; Xu Yang; Qing Lu. Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies. Materials 2020, 13, 4496 .
AMA StyleJiahao Tian, Sang Luo, Ziming Liu, Xu Yang, Qing Lu. Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies. Materials. 2020; 13 (20):4496.
Chicago/Turabian StyleJiahao Tian; Sang Luo; Ziming Liu; Xu Yang; Qing Lu. 2020. "Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies." Materials 13, no. 20: 4496.
Cracking is a common pavement distress that would cause further severe problems if not repaired timely, which means that it is important to accurately extract the information of pavement cracks through detection and segmentation. Automated pavement crack detection and segmentation using deep learning are more efficient and accurate than conventional methods, which could be further improved. While many existing studies have utilized deep learning in pavement crack segmentation, which segments cracks from non‐crack regions, few studies have taken the exact pavement crack detection into account, which identifies cracks in the images from other objects. A two‐step pavement crack detection and segmentation method based on convolutional neural network was proposed in this paper. An automated pavement crack detection algorithm was developed using the modified You Only Look Once 3rd version in the first step. The proposed crack segmentation method in the second step was based on the modified U‐Net, whose encoder was replaced with a pre‐trained ResNet‐34 and the up‐sample part was added with spatial and channel squeeze and excitation (SCSE) modules. Proposed method combines pavement crack detection and segmentation together, so that the detected cracks from the first step are segmented in the second step to improve the accuracy. A dataset of pavement crack images in different circumstances were also built for the study. The F1 score of proposed crack detection and segmentation methods are 90.58% and 95.75%, respectively, which are higher than other state‐of‐the‐art methods. Compared with existing one‐step pavement crack detection or segmentation methods, proposed two‐step method showed advantages of accuracy.
Jingwei Liu; Xu Yang; Stephen Lau; Xin Wang; Sang Luo; Vincent Cheng‐Siong Lee; Ling Ding. Automated pavement crack detection and segmentation based on two‐step convolutional neural network. Computer-Aided Civil and Infrastructure Engineering 2020, 35, 1291 -1305.
AMA StyleJingwei Liu, Xu Yang, Stephen Lau, Xin Wang, Sang Luo, Vincent Cheng‐Siong Lee, Ling Ding. Automated pavement crack detection and segmentation based on two‐step convolutional neural network. Computer-Aided Civil and Infrastructure Engineering. 2020; 35 (11):1291-1305.
Chicago/Turabian StyleJingwei Liu; Xu Yang; Stephen Lau; Xin Wang; Sang Luo; Vincent Cheng‐Siong Lee; Ling Ding. 2020. "Automated pavement crack detection and segmentation based on two‐step convolutional neural network." Computer-Aided Civil and Infrastructure Engineering 35, no. 11: 1291-1305.
Structural indicators of asphalt mixtures, including aggregate gradation, spatial distribution, orientation, shape, angularity, texture, aggregate content, asphalt content and air void content, determine mixture heterogeneity and therefore significantly affect the micromechanical response of mixtures. An approach to the virtual design of mixture microstructure using structural indicators is proposed, based on a digital library of realistic aggregates. The methodology comprises three main steps, as follows: (1) a digital library containing almost 3000 reconstructed grains with quantified morphological properties based on computed tomography (CT) imaging is established; (2) aggregates which are consistent with volumetric and morphological assignments are identified in the library as the aggregate component of the mixture; and (3) the positions and orientations of selected aggregates are determined according to their distributional assignment, and consequently, the asphalt mortar and air void components are identified to obtain the microstructure of the virtual mixture. The proposed approach customizes the morphology and spatial distribution of aggregates and the content of the three phases of specimens to simulate the mixture’s microstructure, which facilitates the study of the correlation between the structural indicators and the mechanical responses of mixtures. Numerical simulations of indirect tensile tests were conducted to show different mechanical properties of obtained specimens.
Can Jin; Feilong Zou; Xu Yang; Kai Liu. 3-D virtual design and microstructural modeling of asphalt mixture based on a digital aggregate library. Computers & Structures 2020, 242, 106378 .
AMA StyleCan Jin, Feilong Zou, Xu Yang, Kai Liu. 3-D virtual design and microstructural modeling of asphalt mixture based on a digital aggregate library. Computers & Structures. 2020; 242 ():106378.
Chicago/Turabian StyleCan Jin; Feilong Zou; Xu Yang; Kai Liu. 2020. "3-D virtual design and microstructural modeling of asphalt mixture based on a digital aggregate library." Computers & Structures 242, no. : 106378.
To address the severe distresses of asphalt pavement, a new type of pavement maintenance treatment, porous ultra-thin overlay (PUTO) with small particle size was proposed. The PUTO has a thickness of 1.5~2.5 cm and a large void ratio of 18~25%. As a newly asphalt mixture, the structure characteristics differ from traditional pavement. Therefore, it is necessary to investigated the fabrication schemes in laboratory and on-site, respectively. In this study, the optimal fabrication schemes, including compaction temperature and number of blows of PUTO were determined based on Cantabro test and volumetric parameters. Then, the corresponding relationship between laboratory and on-site compaction work was then established based on the energy equivalent principle. On this basis, the numbers of on-site rolling passes and the combination method were calculated. The results show that increased compaction temperature and number of blows reduce the height and enhance the compactness of the Marshall sample. With the same temperature and number of blows, the scattering resistance of coarse gradation (PAC-1) is better than that of fine gradation (PAC-2), and the increased asphalt viscosity significantly improves the scattering resistance of the asphalt mixture. To ensure the scattering resistance and volumetric characteristic, the initial compaction temperature of the PAC-1 and PAC-2 should not be lower than 150 °C and 165 °C, respectively. Then, the laboratory compaction work and on-site compaction work were calculated and converted based on the principle of energy equivalence. Consequently, the on-site compaction combination of rolling machines for four asphalt mixtures was determined. According to the volumetric parameters, the paving test section proved that the construction temperature and the on-site rolling combination determined by laboratory tests are reasonable, and ultra-thin overlay has good structural stability, drainage and skid resistance.
Jiahao Tian; Sang Luo; Ziming Liu; Xu Yang; Qing Lu. Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies. 2020, 1 .
AMA StyleJiahao Tian, Sang Luo, Ziming Liu, Xu Yang, Qing Lu. Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies. . 2020; ():1.
Chicago/Turabian StyleJiahao Tian; Sang Luo; Ziming Liu; Xu Yang; Qing Lu. 2020. "Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies." , no. : 1.
To facilitate the reliable, stable and rapid simulation of asphalt mixtures, an approach is proposed to model mixtures’ microstructures adaptively due to a predicted solution region. The methodology comprises four main steps, as follows: (1) the aggregate surface is triangulated to tiny facets based on the three-dimensional (3-D) reconstructed particle; (2) the obtained facets are clustered by a control parameter to identify approximately-planar regions on the particle surface; (3) aggregate models are simplified to polyhedrons by a cutting operation according to rough facet clustering, based on which the asphalt model is obtained by a Boolean operation to construct a trial mixture for a tentative simulation; and (4) according to the solution region of the tentative simulation, aggregates are divided into groups for adaptive simplification to reach a balance between simulation accuracy and computational effort, and the mixture model is prepared for the simulation. Two simulations for the uniaxial compaction test were conducted based on the mixture model before and after simplification. The results indicate that the two mixture models have close simulation results, but the simplified model saved a very large amount of computational time.
Can Jin; Wuxing Zhang; Xu Yang; Kai Liu. Region-based adaptive asphalt mixture microstructural modeling for efficient numerical simulation. Construction and Building Materials 2020, 257, 119431 .
AMA StyleCan Jin, Wuxing Zhang, Xu Yang, Kai Liu. Region-based adaptive asphalt mixture microstructural modeling for efficient numerical simulation. Construction and Building Materials. 2020; 257 ():119431.
Chicago/Turabian StyleCan Jin; Wuxing Zhang; Xu Yang; Kai Liu. 2020. "Region-based adaptive asphalt mixture microstructural modeling for efficient numerical simulation." Construction and Building Materials 257, no. : 119431.
Angularity and surface texture of aggregates are important morphological characteristics, which have significant effects on the micromechanical responses of asphalt composites. A novel approach to quantify and classify the complexity of aggregate angularity and surface texture is proposed from a statistical perspective in this study. The methodology consists of three main steps, as follows: 1) the aggregate is three-dimensional (3D) reconstructed, and the model surface is triangulated into facets to conduct clustering for aggregate angles evaluation; 2) consequently, a reference plane is determined for each facet cluster to quantify the surface texture of a surface area which overlaps the cluster, and thus the surface texture is quantified; and 3) aggregates are classified by using the distribution characteristics of the angularity and surface texture respectively. Based on the quantification with the presented approach, 275 grains were classified by the angularity and surface texture. Results indicate the benefit of the proposed method in accurate quantification and classification of aggregate angularity and surface texture, which facilitate the bridging of the gap between aggregate morphology and micromechanical performance of asphalt composites.
Can Jin; Feilong Zou; Xu Yang; Kai Liu; Pengfei Liu; Markus Oeser. Three-dimensional quantification and classification approach for angularity and surface texture based on surface triangulation of reconstructed aggregates. Construction and Building Materials 2020, 246, 118120 .
AMA StyleCan Jin, Feilong Zou, Xu Yang, Kai Liu, Pengfei Liu, Markus Oeser. Three-dimensional quantification and classification approach for angularity and surface texture based on surface triangulation of reconstructed aggregates. Construction and Building Materials. 2020; 246 ():118120.
Chicago/Turabian StyleCan Jin; Feilong Zou; Xu Yang; Kai Liu; Pengfei Liu; Markus Oeser. 2020. "Three-dimensional quantification and classification approach for angularity and surface texture based on surface triangulation of reconstructed aggregates." Construction and Building Materials 246, no. : 118120.
This paper is aimed at providing a comprehensive experimental work on the viscosity behavior of different modified asphalt binders and mastics, as well as exploring mathematical representations of the results in attempts to predict the viscosity and flow behaviors according to Vinogradov-Malkin and Phillips-Deutsch models. The modified asphalt binders were prepared in the unaged and aged states using styrene-butadienestyrene (SBS), ethylene-vinyl acetate (EVA), and crumb rubber (CR); while the hydrated lime (HL) and fly ash (FA) were selected to produce the binder-filler mastics. To widen the study findings, the additives (polymers, rubber, and fillers) were applied at different possible levels of modification. To prepare the aged bituminous materials, the rolling thin-film oven (RTFO) was utilized for the short-term aging, while the pressure aging vessel (PAV) was further used to induce the possible long-term aging of same materials. Binders and binder-filler mastics were tested using a bob and cup geometry. The viscosity behavior was investigated under various effects of testing conditions including ranges of shear rates and temperatures. It was found that the effect of shear rate dominates and therefore the non-Newtonian shear thinning prevails at low temperatures particularly for binders containing high concentrations of additives. Even the base asphalt binder exhibits shear thinning behavior after a certain limit of shear rate. Based on the studied 38 curves, in general, Vinogradov-Malkin and Phillips-Deutsch models were found in a good agreement with the corresponding measurements especially the latter.
Aboelkasim Diab; Zhanping You; Xuelian Li; Jorge Carvalho Pais; Xu Yang; Siyu Chen. Rheological models for non-newtonian viscosity of modified asphalt binders and mastics. Egyptian Journal of Petroleum 2019, 29, 105 -112.
AMA StyleAboelkasim Diab, Zhanping You, Xuelian Li, Jorge Carvalho Pais, Xu Yang, Siyu Chen. Rheological models for non-newtonian viscosity of modified asphalt binders and mastics. Egyptian Journal of Petroleum. 2019; 29 (2):105-112.
Chicago/Turabian StyleAboelkasim Diab; Zhanping You; Xuelian Li; Jorge Carvalho Pais; Xu Yang; Siyu Chen. 2019. "Rheological models for non-newtonian viscosity of modified asphalt binders and mastics." Egyptian Journal of Petroleum 29, no. 2: 105-112.
This paper presents a numerical investigation of thermal response of mortar panels, incorporating macro-encapsulated paraffin in different forms. Two types of macro capsules were fabricated and tested in this study using an instrumented hot plate device. The experimental results show that macro encapsulated paraffin reduced the temperature and increased time lag in the mortar panels due to the latent heat capacity of paraffin. Finite element models adopting the effective heat capacity method to model phase change effects were able to capture the overall thermal response of panels incorporated with paraffin well. Then, a parametric study was conducted using the validated finite element (FE) modelling technique to investigate the effects of different forms of macro capsules, the quantity of paraffin and the position of macro capsules. It was found that the tube and sphere macro capsules showed similar thermal responses, while the plate shaped capsules may cause a non-uniform temperature distribution in mortar panels. The quantity and position of paraffin have significant effects on the thermal response of the mortal panels. A higher paraffin content results in a significantly longer temperature lag and a lower temperature during the phase transition of paraffin. Furthermore, placing the paraffin away from the heating face can cause a longer temperature lag on the other face, which is desirable for building façade applications.
Sih Ying Kong; Xu Yang; Suvash Chandra Paul; Leong Sing Wong; Branko Šavija. Thermal Response of Mortar Panels with Different Forms of Macro-Encapsulated Phase Change Materials: A Finite Element Study. Energies 2019, 12, 2636 .
AMA StyleSih Ying Kong, Xu Yang, Suvash Chandra Paul, Leong Sing Wong, Branko Šavija. Thermal Response of Mortar Panels with Different Forms of Macro-Encapsulated Phase Change Materials: A Finite Element Study. Energies. 2019; 12 (13):2636.
Chicago/Turabian StyleSih Ying Kong; Xu Yang; Suvash Chandra Paul; Leong Sing Wong; Branko Šavija. 2019. "Thermal Response of Mortar Panels with Different Forms of Macro-Encapsulated Phase Change Materials: A Finite Element Study." Energies 12, no. 13: 2636.
The idea of prolonging the service life of asphalt mixture by improving the self-healing ability of asphalt has received extensive attention in recent years. In view of this, this work synthesized three kinds of encapsulating rejuvenator fibers to improve self-healing properties of asphalt mixtures. A series of characterizations were performed to study the morphology, chemical structure and thermal stability of the three kinds of fibers. Subsequently, the road performance of asphalt mixture containing the fiber were investigated, which included high and low temperature, water sensitivity and fatigue performances. Finally, the self-healing performance of asphalt mixture containing the fiber was investigated by 3PB test. The results revealed that the three kinds of encapsulating rejuvenator fibers were successfully synthesized. The fibers had excellent thermal stability, which met temperature requirements in the mixing and compaction process of asphalt mixtures. Road performance of asphalt mixture containing the fiber met the requirements. Self-healing ability of asphalt mixture containing the fiber was improved. Synergistic action of temperature and rejuvenator could further significantly improve the self-healing ability of the asphalt mixture.
Benan Shu; Shiwen Bao; Shaopeng Wu; Lijie Dong; Chao Li; Xu Yang; José Norambuena-Contreras; Quantao Liu; Qing Wang. Synthesis and Effect of Encapsulating Rejuvenator Fiber on the Performance of Asphalt Mixture. Materials 2019, 12, 1266 .
AMA StyleBenan Shu, Shiwen Bao, Shaopeng Wu, Lijie Dong, Chao Li, Xu Yang, José Norambuena-Contreras, Quantao Liu, Qing Wang. Synthesis and Effect of Encapsulating Rejuvenator Fiber on the Performance of Asphalt Mixture. Materials. 2019; 12 (8):1266.
Chicago/Turabian StyleBenan Shu; Shiwen Bao; Shaopeng Wu; Lijie Dong; Chao Li; Xu Yang; José Norambuena-Contreras; Quantao Liu; Qing Wang. 2019. "Synthesis and Effect of Encapsulating Rejuvenator Fiber on the Performance of Asphalt Mixture." Materials 12, no. 8: 1266.
Porous ultra-thin overlay (PUTO) is a new type of pavement maintenance technology which combines skid resistance and drainage functions. The engineering properties of two high-viscosity modifier (type I and type II) modified asphalt and two gradations (coarse and fine) of asphalt mixtures, including high- temperature rutting resistance, low-temperature crack resistance and moisture sensitivity, were investigated. The dynamic modulus and phase angle of the asphalt mixture under dynamic loading conditions were then analyzed and master curves of dynamic modulus and phase angle were established. Finally, the drainage and skid resistance of the PUTO were evaluated. The results show that the dynamic stability (DS) of the asphalt mixture with coarse gradation is larger than that of the asphalt mixture with fine gradation. The bending strain of four asphalt mixtures shows small differences, the maximum value being 364 με larger than the minimum value, and they all meet the requirements of the specification. The excellent adhesion of the high-viscosity asphalt binder enhances the anti-stripping ability between asphalt and aggregates, enabling the mixture to resist water damage well. As the temperature increases or the load frequency decreases, the dynamic modulus decreases and the phase angle increases. By establishing the master curves of dynamic modulus and phase angle, it can be concluded that gradation as the main skeleton of PUTO asphalt mixture plays a major role in its performance and strength. Under the same rainfall conditions, the asphalt mixture with coarse gradation can transfer water on the pavement surface to the outside more quickly. Coarse gradation is beneficial for the enhancement of the macroscopic structure and improvement of the skid resistance of pavement surface.
Ziming Liu; Sang Luo; Xun Quan; Xiaohao Wei; Xu Yang; Qiang Li. Laboratory evaluation of performance of porous ultra-thin overlay. Construction and Building Materials 2019, 204, 28 -40.
AMA StyleZiming Liu, Sang Luo, Xun Quan, Xiaohao Wei, Xu Yang, Qiang Li. Laboratory evaluation of performance of porous ultra-thin overlay. Construction and Building Materials. 2019; 204 ():28-40.
Chicago/Turabian StyleZiming Liu; Sang Luo; Xun Quan; Xiaohao Wei; Xu Yang; Qiang Li. 2019. "Laboratory evaluation of performance of porous ultra-thin overlay." Construction and Building Materials 204, no. : 28-40.
The hazardous emissions of crumb rubber (CR) modified asphalt during construction has been a concern for a long period. This study aims to identify the emission components in the CR modified asphalt in traditional hot mix asphalt (HMA) and with recently developed warm mix asphalt (WMA). The dynamic headspace gas chromatography–mass spectrometry (GC-MS) was employed for identifying the emission of asphalt binders at 120°C, 140°C and 160°C. The coupling of gas chromatography and Fourier-transform infrared spectroscopy (GC-FTIR) was used to analyze the emission during the plant mixing for conventional HMA, CR-HMA and CR-WMA. The results showed the emission amount was highly dependent on mixing temperature. The warm mix technology can reduce the emission level significantly and should be encouraged in the asphalt mixture containing CR. Asphalt source and other extra additives in producing CR modified asphalt can also affect the emission significantly. Asphalt mixture containing CR can release toxic emissions such as xylene and toluene significantly higher compared to that without CR. In addition, it was found that the emission amount from the GC-MS test for asphalt binder was lower than that in the field test for asphalt mix due to the thin asphalt film of asphalt mix.
Xu Yang; Zhanping You; David Perram; David Hand; Zeyad Ahmed; Wei Wei; Sang Luo. Emission analysis of recycled tire rubber modified asphalt in hot and warm mix conditions. Journal of Hazardous Materials 2018, 365, 942 -951.
AMA StyleXu Yang, Zhanping You, David Perram, David Hand, Zeyad Ahmed, Wei Wei, Sang Luo. Emission analysis of recycled tire rubber modified asphalt in hot and warm mix conditions. Journal of Hazardous Materials. 2018; 365 ():942-951.
Chicago/Turabian StyleXu Yang; Zhanping You; David Perram; David Hand; Zeyad Ahmed; Wei Wei; Sang Luo. 2018. "Emission analysis of recycled tire rubber modified asphalt in hot and warm mix conditions." Journal of Hazardous Materials 365, no. : 942-951.
The reuse of waste tire and biomass is important to environmental protection. The main objective of this study is to investigate the effect of bio-oil on the high-temperature performance of crumb rubber modified asphalt. Two types of crumb rubber powder produced from waste tire, 80-mesh and 20-mesh, were used to prepare the crumb rubber modified asphalt. Four weight ratios of bio-oil to rubber asphalt, 0%, 5%, 10%, and 15%, were chosen to prepare the composite modified asphalt binder in this study. Temperature sweep test and multiple stress creep recovery (MSCR) test were conducted to evaluate the high-temperature of the composite modified asphalt. The results showed that the viscosities of asphalts modified by 20-mesh crumb rubber were greater than that modified by 80-mesh ones. With the addition of bio-oil into crumb rubber asphalt, the viscosities of the composite modified asphalts first increased then decreased. Bio-oil can enhance the high-temperature performance of crumb rubber modified asphalt due to the physical and chemical interactions in a heated asphalt. The short-term aging process may improve the degree of blending between crumb rubber and bio-oil in the heated asphalt dispersion system and enhance the elastic property of crumb rubber modified asphalt.
Yong Lei; Hainian Wang; Ellie H. Fini; Zhanping You; Xu Yang; Junfeng Gao; Shi Dong; Guan Jiang. Evaluation of the effect of bio-oil on the high-temperature performance of rubber modified asphalt. Construction and Building Materials 2018, 191, 692 -701.
AMA StyleYong Lei, Hainian Wang, Ellie H. Fini, Zhanping You, Xu Yang, Junfeng Gao, Shi Dong, Guan Jiang. Evaluation of the effect of bio-oil on the high-temperature performance of rubber modified asphalt. Construction and Building Materials. 2018; 191 ():692-701.
Chicago/Turabian StyleYong Lei; Hainian Wang; Ellie H. Fini; Zhanping You; Xu Yang; Junfeng Gao; Shi Dong; Guan Jiang. 2018. "Evaluation of the effect of bio-oil on the high-temperature performance of rubber modified asphalt." Construction and Building Materials 191, no. : 692-701.
The reconstruction of microstructural models is the prerequisite step for the micromechanical simulation of asphalt concrete. Computer-generated microstructural models have been developed because the traditional X-ray image-based models are costly and time-consuming. One concern for the computer-generated model is the accuracy in aggregate morphology and internal structure compared with the X-ray image-based models. Therefore, it is desirable to generate microstructural models with aggregate morphology and internal structures close to the real asphalt concrete samples. Although aggregate morphology and internal structures for real samples have been previously studied, these parameters for computer-generated models are rarely reported. This study aims to propose an approach to analyze and quantify the aggregate morphology and internal structures of computer-generated microstructural models of asphalt concrete. Sphere clumps were used to represent aggregate particles and air voids. Then the aggregate skeleton and air voids were generated based on which both discrete element (DE) models and finite-element models on the microscale can be reconstructed. The aggregate sphericity and angularity, air void distribution, aggregate orientation, aggregate contact points, and aggregate distribution were analyzed based on the DE model. Some novel approaches were proposed to quantify these parameters. The results showed that all these parameters can be successfully obtained and quantified. The outcomes of this study can serve as a prestep of the ultimate goal of reconstructing microstructural models that display aggregate morphology and an internal structure comparable to real asphalt concrete samples.
Xu Yang; Zhanping You; Can Jin; Aboelkasim Diab; Mohd Rosli Mohd Hasan. Aggregate Morphology and Internal Structure for Asphalt Concrete: Prestep of Computer-Generated Microstructural Models. International Journal of Geomechanics 2018, 18, 06018024 .
AMA StyleXu Yang, Zhanping You, Can Jin, Aboelkasim Diab, Mohd Rosli Mohd Hasan. Aggregate Morphology and Internal Structure for Asphalt Concrete: Prestep of Computer-Generated Microstructural Models. International Journal of Geomechanics. 2018; 18 (10):06018024.
Chicago/Turabian StyleXu Yang; Zhanping You; Can Jin; Aboelkasim Diab; Mohd Rosli Mohd Hasan. 2018. "Aggregate Morphology and Internal Structure for Asphalt Concrete: Prestep of Computer-Generated Microstructural Models." International Journal of Geomechanics 18, no. 10: 06018024.
From the rheological behavior of bitumen, one can understand the physical properties of water-foamed bitumen used in warm mix asphalt. Previously, rheological behaviors of water-foamed bitumen such as apparent viscosity, agitation torque, and shear rate have not been well documented. The objectives of this study are as follows: (1) evaluating the accuracy of the cup-and-bob test with a dynamic shear rheometer to investigate the rheological behavior of water-foamed bitumen, (2) analyzing the rheological behavior of water-foamed bitumen at various temperatures, and (3) proposing an optimum water content that decreases the apparent viscosity and required agitation torque of water-foamed bitumen. Bitumen with various water contents (ranging from 0.0 to 3.0% bitumen content by mass) were prepared for rheological testing. The optimum water content at each of these foaming temperatures was determined based on the testing results. This study concludes that the current cup-and-bob test methods accurately describe the rheological behavior of water-foamed bitumen. Within the accepted water content range, the apparent viscosity and required agitation torque of water-foamed bitumen decrease more dramatically as water content increases.
Lingyun You; Zhanping You; Xu Yang; Dongdong Ge; Songtao Lv. Laboratory Testing of Rheological Behavior of Water-Foamed Bitumen. Journal of Materials in Civil Engineering 2018, 30, 04018153 .
AMA StyleLingyun You, Zhanping You, Xu Yang, Dongdong Ge, Songtao Lv. Laboratory Testing of Rheological Behavior of Water-Foamed Bitumen. Journal of Materials in Civil Engineering. 2018; 30 (8):04018153.
Chicago/Turabian StyleLingyun You; Zhanping You; Xu Yang; Dongdong Ge; Songtao Lv. 2018. "Laboratory Testing of Rheological Behavior of Water-Foamed Bitumen." Journal of Materials in Civil Engineering 30, no. 8: 04018153.
Effective shear transfer at the interface of glass fibre reinforced polymer (GFRP) and concrete sections is crucial to achieve structural integrity of the composite panel. This study proposed a shear connector consisting of circular hollow sections (CHS) to enhance shear transfer between concrete and GFRP. Push-out and three-point bending tests were conducted to evaluate the static response of the proposed connectors compared to the adhesive bonding. The results showed that GFRP-concrete composite section using proposed shear connectors achieved partial composite action and non-linear behavior could be observed before the GFRP section failed in shear along the fibre direction at the contact zone. The mechanical properties of the connectors can affect the bearing capacity and stiffness of the composite structure. Numerical simulation using finite element (FE) method was able to capture the overall mechanical response with respect to loading force and deformation. Using a validated FE modelling technique, a comprehensive parametric study was carried out. Results showed that flange thickness, fibre orientation and shear connector arrangement can significantly affect the flexural capacity of GFRP-concrete composite.
Sih Ying Kong; Xu Yang; Ze Yang Lee. Mechanical performance and numerical simulation of GFRP-concrete composite panel with circular hollow connectors and epoxy adhesion. Construction and Building Materials 2018, 184, 643 -654.
AMA StyleSih Ying Kong, Xu Yang, Ze Yang Lee. Mechanical performance and numerical simulation of GFRP-concrete composite panel with circular hollow connectors and epoxy adhesion. Construction and Building Materials. 2018; 184 ():643-654.
Chicago/Turabian StyleSih Ying Kong; Xu Yang; Ze Yang Lee. 2018. "Mechanical performance and numerical simulation of GFRP-concrete composite panel with circular hollow connectors and epoxy adhesion." Construction and Building Materials 184, no. : 643-654.
Concrete is one of the most extensively used building materials. In the cold salty lake region, concrete structures generally undergo freeze–thaw cycles subjected to sulfate in the winter and early spring, and experience carbonation during the rest of the year. It is necessary to study the degradation process of concrete during the alternation of freeze–thaw cycles subjected to sulfate and carbonation. In this article, two types of experiments were implemented: freeze–thaw cycles subjected to sulfate (SF), and the alteration of freeze–thaw cycles subjected to sulfate and carbonation (SFC). Computed tomography (CT), as a non-destructive testing technology, was adopted to reveal the rules of pore changes and show generated cracks after the alternation of freeze–thaw cycles subjected to sulfate and carbonation. CT scanning results showed that pore numbers, pore areas, and porosity of each cross-section changed to some extent. Due to the different distances from the top, the changes of each cross-section were found to be dissimilar. From the 2D images, SFC specimens were identified to have corner erosion and internal cracks, and were damaged more severely than SF specimens. The compressive strength loss of SF specimens was very limited in the early state; after a certain period of erosion, the compressive strength decreased rapidly. The compressive strength loss of specimens under SFC was larger than the specimens under SF. Carbonation constantly consumed calcium ions, which negatively affected the stability of porosity system. Freeze-thaw cycles caused aperture degradation, coarsened the pore structure, and with the additional interaction of sulfate erosion, aggravated the deterioration of concrete.
Fang Liu; Zhanping You; Xu Yang; Hainian Wang. Macro-micro degradation process of fly ash concrete under alternation of freeze-thaw cycles subjected to sulfate and carbonation. Construction and Building Materials 2018, 181, 369 -380.
AMA StyleFang Liu, Zhanping You, Xu Yang, Hainian Wang. Macro-micro degradation process of fly ash concrete under alternation of freeze-thaw cycles subjected to sulfate and carbonation. Construction and Building Materials. 2018; 181 ():369-380.
Chicago/Turabian StyleFang Liu; Zhanping You; Xu Yang; Hainian Wang. 2018. "Macro-micro degradation process of fly ash concrete under alternation of freeze-thaw cycles subjected to sulfate and carbonation." Construction and Building Materials 181, no. : 369-380.
In order to improve the anti-rutting ability of grouted open-graded asphalt concrete (GOAC) for semi-flexible pavement, latex modified cement mortar was introduced in this study. A comprehensive performance evaluation was carried out to study the viability of the GOAC with latex modified cement mortar. The asphalt skeleton gradation was determined by adopting the GOAC experience in Japan. The asphalt skeleton was designed based on porosity, strength and runoff resistance, while the latex modified cement mortar was designed based on fluidity, flexural strength and compressive strength. The results showed that the addition of the latex can significantly improve the 7-day flexural strength while only slightly compromise the fluidity. A grouting saturation degree of higher than 96% was found for the GOAC-13 and GOAC-16. The performance of the latex modified GOAC was compared with conventional asphalt concrete. It was found that the GOAC has significantly better rutting resistance, but the moisture susceptibility, low-temperature crack resistance and fatigue performance were weaker. However, the results also showed that the moisture susceptibility and the low-temperature performance for the latex modified GOAC were at acceptable levels. In addition, it was found that the Marshall immersion test is not suitable for evaluating the moisture susceptibility of GOAC in comparison with the freeze–thaw conditioning method.
Sang Luo; Xu Yang; Ke Zhong; Jun Yin. Open-graded asphalt concrete grouted by latex modified cement mortar. Road Materials and Pavement Design 2018, 21, 61 -77.
AMA StyleSang Luo, Xu Yang, Ke Zhong, Jun Yin. Open-graded asphalt concrete grouted by latex modified cement mortar. Road Materials and Pavement Design. 2018; 21 (1):61-77.
Chicago/Turabian StyleSang Luo; Xu Yang; Ke Zhong; Jun Yin. 2018. "Open-graded asphalt concrete grouted by latex modified cement mortar." Road Materials and Pavement Design 21, no. 1: 61-77.
The long-span steel bridge has experienced a rapid growth in China during the last two decades. Steel deck surfacing plays an important role in the durability of long-span steel bridges. So far, three types of surfacing materials have been used in China’s experience: epoxy asphalt (EA), Gussasphalt (GA), and stone matrix asphalt (SMA). Four main double-layered surfacing structures have been used via the combination of the three materials, GA-EA (EA on the top), GA-SMA, EA-SMA, and EA-EA. The objective of this study is to identify the best surfacing strategy from the four existing double-layered structures. A comprehensive performance evaluation was conducted to achieve this goal. The rutting resistance, low temperature performance, fatigue performance, and moisture damage resistance were evaluated for the individual surfacing materials, double-layered surfacing structures, and the composite structures consisting of steel deck and surfacing structures. The results showed that EA-EA had the best high-temperature performance, GA-EA had the best low-temperature performance, GA concrete had the lowest moisture susceptibility, and GA-EA possessed the best fatigue performance. In addition, the layer position had an influence on the rutting performance of the double-layered structure. Then, a simple ranking method taking account into the comprehensive performance was used to identify the best surfacing strategy. The GA-EA structure was found to be the best surfacing strategy for long-span steel bridges in China after the comparison.
Sang Luo; Zhendong Qian; Xu Yang; Qing Lu. Laboratory Evaluation of Double-Layered Pavement Structures for Long-Span Steel Bridge Decks. Journal of Materials in Civil Engineering 2018, 30, 04018111 .
AMA StyleSang Luo, Zhendong Qian, Xu Yang, Qing Lu. Laboratory Evaluation of Double-Layered Pavement Structures for Long-Span Steel Bridge Decks. Journal of Materials in Civil Engineering. 2018; 30 (6):04018111.
Chicago/Turabian StyleSang Luo; Zhendong Qian; Xu Yang; Qing Lu. 2018. "Laboratory Evaluation of Double-Layered Pavement Structures for Long-Span Steel Bridge Decks." Journal of Materials in Civil Engineering 30, no. 6: 04018111.
Reliable transverse crack prediction can benefit the design and maintenance and improve the reliability of field investigation for asphalt pavement in permafrost regions of Qinghai-Tibet plateau. This study adopted the crack prediction model in the newly developed pavement design method named Pavement ME Design (PMED) and the modified grey predictive model (GM (1, 1)) to predict the transverse crack of asphalt pavement in permafrost regions. The complementary advantages for the two models based on the weight distribution theory were discussed, and a combined prediction model (PME-DGM combination model) taking account into region characteristics was developed. Finally, the applicability of combined prediction model was analyzed. The result showed that, the predictive accuracy of PME-DGM combination model established by the error sum of squares reciprocal method was the highest, the best weight allocations for each sub-model were LNCH = 0.601 and LDGM = 0.399, and the combination model can be applied in the permafrost region involved in this paper; The combination model is more appropriate in predicting the development trend of transverse crack of project-level asphalt pavement in permafrost regions; For PMED predictive model, this study raised a modified method base on a third-party model (DGM (1,1), and the result showed that the method worked well in the permafrost region of Qinghai-Tibet plateau.
Chen Zhang; Hainian Wang; Xu Yang; Zhanping You. A Combinational Prediction Model for Transverse Crack of Asphalt Pavement. KSCE Journal of Civil Engineering 2018, 22, 2109 -2117.
AMA StyleChen Zhang, Hainian Wang, Xu Yang, Zhanping You. A Combinational Prediction Model for Transverse Crack of Asphalt Pavement. KSCE Journal of Civil Engineering. 2018; 22 (6):2109-2117.
Chicago/Turabian StyleChen Zhang; Hainian Wang; Xu Yang; Zhanping You. 2018. "A Combinational Prediction Model for Transverse Crack of Asphalt Pavement." KSCE Journal of Civil Engineering 22, no. 6: 2109-2117.