scispace - formally typeset
Search or ask a question
Author

Yan-wei Li

Bio: Yan-wei Li is an academic researcher. The author has contributed to research in topics: Asphalt & Materials science. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this paper , the authors investigated the mechanical response of asphalt surfaces under moving traffic loads using the three-dimensional (3D) discrete element method (DEM) and established a discrete element model for asphalt surface based on the random generation algorithm of irregular particles.
Abstract: This paper investigates the mechanical response of asphalt surfaces under moving traffic loads using the three-dimensional (3D) discrete element method (DEM). As an example of a semirigid base asphalt pavement, a discrete element model for asphalt surface was established based on the random generation algorithm of irregular particles in Python language and DEM. The model considered the temperature gradient and fatigue damage to simulate the permanent deformations, shear stresses, and strains in asphalt surfaces under different working conditions (e.g., different temperatures and numbers of repeated loads). Part of the simulation results was verified by performing a full-scale accelerated loading test (ALT). Results show that the 3D discrete element model embedded with temperature gradient and fatigue damage could be used to predict the mechanical response of asphalt surfaces under repeated loads. As the temperature increased, the mechanical response of asphalt surfaces increased. The middle surface was the main area of shear stresses in semirigid base asphalt pavements. Due to fatigue damage, the stresses and strains in asphalt surfaces increased with the number of repeated loads.

4 citations

Proceedings ArticleDOI
02 Jul 2014
TL;DR: In this article, the effects of asphalt-aggregate ratios and compaction efforts on the horizontal aggregate homogeneity in asphalt mixtures were investigated, and the results showed that the horizontal aggregation homogeneity is best with the optimum asphaltaggregate ratio and with an increase in compaction effort.
Abstract: Based on the index of aggregate homogeneity, the effects of asphalt-aggregate ratios and compaction efforts on the horizontal aggregate homogeneity in asphalt mixtures were investigated. Meanwhile, using a two-dimensional indirect tensile test (IDT) model of asphalt mixtures, established by means of a finite element method (FEM), the effects were analyzed from the viewpoint of numerical simulation and the obtained results were verified by an actual IDT. Results show that the horizontal aggregate homogeneity in asphalt mixtures is best with the optimum asphalt-aggregate ratio. With an increase in compaction effort, the horizontal aggregate homogeneity in asphalt mixtures improves, and there is an obvious relationship between variations in IDT mechanical parameters and horizontal aggregate homogeneity in asphalt mixtures. The greater the variation coefficient of mechanical parameters is, the worse the horizontal aggregate homogeneity is, and vice versa.

2 citations

Journal ArticleDOI
TL;DR: In this paper , the authors investigated the effects of a new compound anti-stripping additive called DMA-NSDD, which comprised dopamine methacrylamide (DMA) that is a marine biomimetic material and nano-silicon dioxide dispersion (NSDD), on the performance properties of asphalt and its mixtures by experiments.

1 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, a multi-direction indirect tensile stiffness modulus (ITSM) test was proposed to quantify the homogeneity of produced asphalt mixtures with reclaimed asphalt pavement (RAP) materials.
Abstract: The homogeneity of asphalt mixtures blended with reclaimed asphalt pavement (RAP) is affected by many factors. Due to the complicated compositions of recycled asphalt mixtures, the inhomogeneity issue might cause insufficient mechanical properties of asphalt mixtures, even though a design method was appropriately adopted. Therefore, it is of great significance to study the influence of mixing conditions on the homogeneity of asphalt mixtures blended with RAP materials. This study focused on the macro-scale homogeneity of produced asphalt mixtures. Specifically, asphalt mixtures incorporated with 40% RAP content were produced in a laboratory using different mixing times and mixing temperatures. A multi-direction indirect tensile stiffness modulus (ITSM) test was proposed to quantify the homogeneity of produced samples. In addition, the digital image processing (DIP) method was used to identify the distribution of aggregates and RAP binder. The results indicated that the influence of mixing time on the macro-homogeneity of asphalt mixtures indicated that a longer mixing time was favorable for the material dispersion. The influence of mixing temperature mainly rested on two perspectives. One was that the temperature variation induced the change of binder viscosity. The other was that the temperature influences the diffusion process between RAP binder and new bitumen, which further affected the mechanical performance of produced asphalt mixtures.

4 citations

Journal ArticleDOI
TL;DR: In this paper , a three-dimensional meso-structure discrete element model of asphalt pavement was generated with the FISH programming language and its mesomechanical response under vehicle load was analyzed.
Abstract: Numerical simulation is an effective way to study the mechanical response of asphalt pavement, which is very important for the pavement structural design. In this study, a three-dimensional meso-structure discrete element model of asphalt pavement was generated with the FISH programming language and its meso-mechanical response under vehicle load was analyzed. The contact forces within the asphalt pavement, in asphalt mastic, in coarse aggregates and between asphalt mastic and coarse aggregates were studied. The results of the study show that the contact forces within the asphalt mixture are highly uneven. The number of contact points in coarse aggregates account only for about 10% of all contact points while the sum of the contact forces in coarse aggregates contributes to over 50% of all contact forces. This demonstrates that the coarse aggregates bear most of the vehicle load. The average normal contact force in coarse aggregates is about 5 N and the average tangential contact force in coarse aggregates is about 2 N. The modeling results provide a quantitative understanding of the distribution of loading in asphalt pavement.

1 citations

Journal ArticleDOI
TL;DR: Based on thermal-mechanical coupling simulation analysis and physical engineering tracking observation, the mechanical behavior and response of a continuously reinforced concrete and asphalt concrete composite pavement layer were analyzed, and the causes of cracking on the surface and bottom of the asphalt layer were revealed as discussed by the authors .
Abstract: Based on thermal–mechanical coupling simulation analysis and physical engineering tracking observation, the mechanical behavior and response of a continuously reinforced concrete and asphalt concrete (CRC + AC) composite pavement layer were analyzed, and the causes of cracking on the surface and bottom of the asphalt layer were revealed. Studies have shown that under normal driving conditions, the AC layer, which is usually in the position of the wheel load gap and wheel load side, more easily generates a longitudinal “corresponding crack”. Compared to normal driving, longitudinal cracks are generated more easily inside of the curve, and transverse cracks occur more easily on poor stadia curves. When the AC layer thickness is less than 8 cm, the AC layer is more prone to bottom-up cracking, and it is more prone to top-down cracking when it is more than 8 cm thick. Comprehensively considering the tensile stress, shear stress, and the thickness of the AC layer, it is recommended that the suitable thickness range of the AC layer is 8 cm~14 cm. The calculated results show good agreement with the physical engineering investigation. The research results can provide a theoretical and scientific basis for cracking control and the rational design of a CRC + AC composite pavement layer.

1 citations

Journal ArticleDOI
13 Dec 2022-Coatings
TL;DR: Wang et al. as mentioned in this paper analyzed the effect of different anti-stripping agents on the improvement of asphalt-granite aggregate adhesion properties based on the surface free energy (SFE) theory.
Abstract: Granite is very widely distributed in the world, but granite is an acidic aggregate with poor adhesion to asphalt. In untreated asphalt mixtures, asphalt pavement water damage and loose disease are more prominent, affecting the service life of the pavement and service level. Enhancing the road performance of granite asphalt mixture generally improves the adhesion properties of asphalt and granite. Qingchuan rock asphalt, anti-stripping agent KH5, aliphatic amine anti-stripping agent AJ-1 and two groups of the composite anti-stripping agents were used to modify the asphalt and analyze the effect of different anti-stripping agents on the improvement of asphalt-granite aggregate adhesion properties based on the surface free energy (SFE) theory. Second, the effect of anti-stripping agents on the rheological properties of asphalt were analyzed by rheological tests, and the modification effect of granite asphalt mixture road performance was evaluated by Marshall tests. The aging of asphalt and asphalt mixture was simulated by thermal oxygen aging, and the durability of different anti-stripping agents was investigated by comparing the performance of asphalt and asphalt mixtures before and after aging. The results showed that Qingchuan rock asphalt can effectively enhance the high-temperature stability and anti-aging properties of asphalt mixes, but the low temperature performance was relatively poor. KH5 and AJ-1 can make up for the lack of low temperature performance of rock asphalt, but the water stability of asphalt mixes decreases after aging. All five groups of anti-stripping agents improve the adhesion of granite-asphalt and the water stability of the asphalt mixture to some extent. Considering the aging effect, the order of granite-asphalt mixture water stability is: KH/RAMA > AJ/RAMA > RAMA > KHMA > AJMA.

1 citations

Journal ArticleDOI
TL;DR: In this article , the authors analyzed the dynamic responses of asphalt pavement in dry and saturated conditions under full-scale accelerated loading and found that the increase in vehicle load significantly increased the magnitudes of stress, strain, and pore water pressure.
Abstract: Asphalt pavement presents diverse dynamic responses to vehicle loading in dry and saturated conditions, which can be systematically explored by numerical simulation. Building a numerical model based on the actual conditions of asphalt pavement is necessary, and relevant field tests should be subsequently conducted to monitor dynamic responses to calibrate and validate the numerical model. On the basis of strictly controlling the paths of vehicle wheels during field tests, this study numerically analyzed the dynamic responses of asphalt pavement in dry and saturated conditions under full-scale accelerated loading. The trends of the modeling results were consistent with those of field measurements. The increase in vehicle load significantly increased the magnitudes of stress, strain, and pore water pressure, while vehicle speed showed an obvious impact on pore water pressure. The dynamic responses decreased with pavement depths. Water made the dynamic responses more complex, and pore water pressure significantly decreased with depth within the upper layer of saturated asphalt pavement. Transverse distributions of indicators presented obvious compressive states in the regions in direct contact with vehicle wheels, while tensile states were found in the range of the middle vehicle axle. The numerical results provided a basis for field measurements in future studies, especially for the exploration of factors of temperature and layer depth.

1 citations