Study on Mechanical Responses of Typical Asphalt Pavement Structure

2013 ◽  
Vol 361-363 ◽  
pp. 1723-1726
Author(s):  
Xiao Li ◽  
Shan Qin Chen ◽  
Qi Wei Li

Semi rigid asphalt pavement, flexible base asphalt and composite base asphalt pavement are the main structure forms of asphalt pavement. The mechanical distributions are different in those structures. Based on elastic layer system, this paper took the Shell designing software BISAR3.0 as calculation tool to get the tensile strain of three kinds of models, the distribution of main mechanical response were compared with each other using the ORIGIN8.0. Then a comprehensive analysis was made based on the mechanical response distributions of the three structures. The results show that: flexible tensile strain and vertical strain in the bottom of asphalt layers of semi rigid base structure is the smallest, as it shows better performance. It proves that the design specification adopting now is not suitable for semi rigid base pavement

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2490 ◽  
Author(s):  
Yazhen Sun ◽  
Bincheng Gu ◽  
Lin Gao ◽  
Linjiang Li ◽  
Rui Guo ◽  
...  

In order to represent the mechanical response laws of high-modulus asphalt pavement (HMAP) faithfully and objectively, the viscoelasticity of high-modulus asphalt mixture (HMAM) was considered, and the viscoelastic mechanical responses were calculated systematically based on moving load by numerical simulations. The performances of the HMAP in resistance to the deformation and the cracking at the bottom layer were compared with the ordinary asphalt pavement. Firstly, Lubao and Honeywell 7686 (H7686) were selected as the high modulus modifiers. The laboratory investigations of Asphalt mix-70 penetration, Asphalt mix-SBS (styrene-butadiene-styrene), HMAM-Lubao and HMAM-H7686 were carried out by dynamic modulus tests and wheel tracking tests. The conventional performances related to the purpose of using the HMAM were indicated. The master curves of the storage moduli were obtained and the viscoelastic parameters were fitted based on viscoelastic theories. Secondly, 3D pavement models based on moving loads for the viscoelastic structures were built using the non-linear finite element software ABAQUS. The wheel path was discretized in time and space to apply the Haversine wave load, and then the mechanical responses of four kinds of asphalt pavement were calculated. Finally, the sensitivity analysis was carried out. The results showed that the addition of the high modulus modifiers can improve the resistance to high-temperature rutting of the pavements. Except for the tensile strain and stress at the bottom of the underlayer, other responses decreased with the increases of the dynamic moduli and the change laws of the tensile strain and stress were affected by the range of the dynamic modulus. The tensile stress at the bottom of the asphalt layer would be too large if the modulus of the layer were too large, and a larger tensile strain would result. Therefore, the range of the modulus must be restricted to avoid the cracking due to excessive tension when using the HMAM. The resistance of the HMAP to deformation was better and the HMAP was less sensitive to load changes and could better withstand the adverse effects inflicted by heavy loads.


2014 ◽  
Vol 1023 ◽  
pp. 28-31
Author(s):  
Li Min Li

With the constant increasing of traffic flow and axle load, the early failure of semi-rigid base asphalt pavement is increasingly serious in China. The bad durability and short service life of pavement have become main obstacles in road construction development. Based on the experience of successful application, the early failure of semi-rigid base asphalt pavement is solved, and the service life of pavement is increased by using of the composite asphalt pavement. To solve the design problem of the composite asphalt pavement , its mechanical properties influence results of are obtained by the factors, such as shear strain, shear stress, compression strain on top of subgrade, etc, by a lot of calculation using Shell pavement design software. These provide theoretical basis for durable asphalt pavement design based on rut-resistance property.


2014 ◽  
Vol 580-583 ◽  
pp. 632-635
Author(s):  
Li Ya Su

With the rapid development of traffic cause in our country, the operating requirement of driving load factors to pavement structure become higher and higher. The Semi-rigid base asphalt pavement structure exposed some defects and shortcomings, so the study of flexible base asphalt pavement structure is put on the agenda under the circumstances.Based on the research achievements at home and abroad of the existing asphalt pavement structure , choosing different elastic modulus and thickness to calculate and analyze the flexible base by ANSYS, gaining the law and trend of mechanics response (the vertical displacement and tensile stress) about pavement structure for the flexible base pavement of each layer foundation to provide the design reference.


2013 ◽  
Vol 361-363 ◽  
pp. 1869-1872 ◽  
Author(s):  
Sheng Jie Liu ◽  
Qing Long You

This paper examines theoretically the possible mechanical response changes on both bituminous pavement structure using linear elastic method, the change regulation of deflection,stress on the bottom of base and subbase and compress strain on the top of subgrades between semi-rigid base and flexible pavement pavement. In the load application procedure, a dual wheel with the a series of pressure was chosen.The results have shown that the deflection tensile stress and subgrade compressive strain on the surface increase with the increase of axle load and they would result in serious effect of overloading on the earlier damage of asphalt pavement.


2013 ◽  
Vol 405-408 ◽  
pp. 1745-1752
Author(s):  
Li Juan Zhang

The purpose of this paper is to study dynamic-characteristics of asphalt-pavement on semi-rigid base loaded with moving, heavy-load. Based on transient-dynamics theory, three-dimensional finite-element (FE) model was developed for structural dynamic-responses analysis using ANSYS software. The heavy-duty axle-load model was established according to Belgium-Design Code, and the dynamic-load was simplified as sinusoidal-wave load. For the pavement mechanics indexes (road-surface deflection, the vertical and lateral stress, the shear stress and the strain), the time-history curves and distribution conditions in the structure were presented. Expect tensile-strain at surface-layer, the relationship between axle-load weight and mechanic-indexes are almost linearly proportional. The calculation shows that under moving heavy-load, the surface-layer suffers from rather high vertical compressive-stress and shear-stress, the base and subbase are loaded with high tensile-stress and the subgrade top undergoes large vertical-strain . For asphalt-pavement on semi-rigid loaded with moving, heavy-load, besides the conventional indexes (including road-surface deflection and tensile-stress at the bottom of base or subbase), the design indexes should also include the shear-stress on road surface, the vertical-strain on the top of subgrade and the vertical compressive-stress on road surface.


2013 ◽  
Vol 838-841 ◽  
pp. 1221-1226
Author(s):  
Xu Liang ◽  
Yin Gu ◽  
Jin Chang Wang ◽  
Ming Xing Yan ◽  
Si Zeng You

Asphalt pavement with semi-rigid base is the major structure adopted in the new built highway and municipal roads in China. So as to reduce the unfavorable impact on the rehabilitation of municipal roads which require quick resumption of traffic, better base materials should be adopted. If a pavement base fails, the flexible base, i.e. large stone asphalt mixture (LSAM), should be employed in the pavement rehabilitation practice. Focusing on the practice pavement sections using LSAM as base in Hangzhou municipal roads, the effect factors of subgrade modulus, base modulus and base thickness on surface deflection and bending strain in base bottom is analyzed. That work is done through finite element method of software BISAR3.0. The results provide a practice reference for municipal roads rehabilitation needing to open traffic early.


2011 ◽  
Vol 97-98 ◽  
pp. 146-150 ◽  
Author(s):  
Chun Feng Yang ◽  
Hui Ran Pi ◽  
Tian Xiao ◽  
Can Zhang Jin

Viewing so many overload vehicles, this paper analyzes the stress distribution of asphalt pavement structure under heavy traffic theoretically, according to the main asphalt pavement structure form in our country. By using elastic layer theory and BISAR3.0 program, analyzed the mechanical response variation of semi-rigid base asphalt pavement under different axle loads. The results showed that the mechanical response and the stress indexes of pavement structure under heavy traffic changed significantly. Therefore, in asphalt pavement design, the impact of heavy traffic should be fully considered and we must take measures to control the overload situation.


2011 ◽  
Vol 255-260 ◽  
pp. 3426-3431 ◽  
Author(s):  
Jin Ting Wu ◽  
Fen Ye ◽  
Yin Ting Wu

The internal mechanical response of asphalt pavement structure is difficult to be obtained because of the limitations of theoretical calculation and present testing methods. In order to get practical information of instructure layers, this paper analyzed the cumulative and instantaneous strains of layers’ bottom of semi-rigid base asphalt pavement based on Accelerated Pavement Testing and Fiber Bragg Grating sensors, as well as got the spatial distribution and time-variation law of longitudinal, lateral and vertical strain responses under controlled loading condition. The research result shows that under the moving vehicle loads, there is an obvious alternative property of tension-compression as the strain response of the pavement structure, and different variation shapes of instantaneous stain are in different layers from top to down. Also the measured instantaneous three-direction strain of the bottom of each surface are higher than the calculated values with BISAR, while they anatomizes well in base. This paper can be regarded as useful and tentative research and application on future correlative study.


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