Mechanics Analysis of Semi-Rigid Subgrade Pavement Structure

2014 ◽  
Vol 580-583 ◽  
pp. 105-108
Author(s):  
Li Ya Su
Keyword(s):  
Tensile Stress ◽  
Elasticity Modulus ◽  
Asphalt Pavement ◽  
Vertical Displacement ◽  
Pavement Design ◽  
Rigid Base ◽  
Mechanics Analysis ◽  
Pavement Structure ◽  
Early Damage

The semi-rigid base asphalt pavement structure was choose often used to the highway in our country, but the semi-rigid base asphalt pavement early damage almost has become a common phenomenon.In this paper, the rule and trend of mechanics response about pavement structure (the vertical displacement and tensile stress) were analyzed under the semi-rigid base choose different elasticity modulus and thickness by ANSYS for muti-layer foundation of semi-rigid base pavement design to provide reference.

Mechanics Analysis of Flexible Base Pavement Structure

2014 ◽  
Vol 580-583 ◽  
pp. 632-635
Author(s):  
Li Ya Su
Keyword(s):  
Elastic Modulus ◽  
Tensile Stress ◽  
Asphalt Pavement ◽  
Rapid Development ◽  
Vertical Displacement ◽  
Rigid Base ◽  
Load Factors ◽  
Mechanics Analysis ◽  
Flexible Base ◽  
Pavement Structure

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.

Effect of Asphalt Layer Modulus on the Mechanical Properties and Service Life of Heavy Load Semi-Rigid Asphalt Pavement

2011 ◽  
Vol 368-373 ◽  
pp. 193-196
Author(s):  
Xiao Hua Wang ◽  
Ji Shu Sun ◽  
Tian Xiao ◽  
Hui Ran Pi
Keyword(s):  
Mechanical Properties ◽  
Service Life ◽  
Tensile Stress ◽  
Asphalt Pavement ◽  
Pavement Design ◽  
Heavy Load ◽  
Surface Deflection ◽  
Pavement Structure ◽  
Base Course ◽  
Design Result

Asphalt layer modulus is one of the important mechanical parameters in pavement design. It will directly influence the design result and the mechanical properties of asphalt pavement structure. Using pavement design and analysis software, the effects of asphalt layer modulus on surface deflection, tensile stress at the bottom of base and sub-base course, stress at the the bottom of asphalt layer and service life of heavy load semi-rigid asphalt pavement structure were analyzed systematically. And the influencing laws were analyzed, too. The results indicate that the mechanical properties, deforming characteristics and service life of heavy load asphalt pavement were influnced significantly by asphalt layer modulus. With the increasing of asphalt layer modulus, the surface deflection, tensile stress at the bottom of base and sub-base course would significantly decrease, and service life of heavy load semi-rigid asphalt pavement structure would be improved.

scholarly journals Response Characteristics of Inverted-base Asphalt Pavement Structure in Cold Area under Multi-axle Loads

2020 ◽  
Vol 7 (4) ◽  
pp. 141-146
Author(s):  
Lin Wang ◽  
Chao Shan ◽  
Chuanfeng Zheng
Keyword(s):  
Tensile Stress ◽  
Asphalt Pavement ◽  
Base Layer ◽  
Rigid Base ◽  
Element Analysis ◽  
The Road ◽  
Response Characteristics ◽  
Pavement Structure ◽  
Axle Loads ◽  
Base Course

In cold areas, semi-rigid base asphalt pavement is prone to generate reflection cracks due to thermal contraction and dry shrinkage, and the base layer cracks can cause surface layer cracking and shorten the service life of the pavement. Aiming at understanding the response characteristics of asphalt pavement structure under multi-axle loads in cold areas, this paper took semi-rigid base asphalt pavement and inverted-base asphalt pavement as the research objects, and employed ANSYS to conduct finite element analysis on them to figure out the response characteristics of the asphalt pavement structure under the condition of different multi-axle loads and graded macadam base course. The research results showed that, the action of multi-axal loads increased the tensile stress of the base layer of the asphalt pavement and the tensile stress of the base layer of the semi-rigid base asphalt pavement, and increased the road surface deflection, which had resulted in insufficient bearing capacity of the pavement structure, and thus causing significant damages to the asphalt pavement; analysis of the response characteristics of the two types of asphalt pavement showed that, adding a graded macadam base course as the stress-absorbing layer is conductive to reducing the tensile stress of the base layer of the semi-rigid base asphalt pavement and effectively delaying or inhibiting reflection cracks generating on the pavement. The study of this paper provided a theoretical reference for the design and construction of asphalt pavement.

Key Technique on the Process Control for Construction of Hohhot Circle Expressway Asphalt Pavements

2012 ◽  
Vol 256-259 ◽  
pp. 1748-1753
Author(s):  
Bin Zhao ◽  
Pei Wen Hao
Keyword(s):  
Inner Mongolia ◽  
Raw Materials ◽  
Asphalt Pavement ◽  
Load Capacity ◽  
Asphalt Mixture ◽  
Natural Increase ◽  
Rigid Base ◽  
Construction Technology ◽  
Pavement Structure ◽  
Major Section

As vehicle flow on arterial highway in Inner Mongolia sharply increased, the originally designed natural increase rate of 8% per year has been exceeded on the vehicle flow in some sections. According to statistics, monthly average vehicle flow on major section of G6 expressway has reached a standard flow of 67478 vehicles per day and night, of which in 70-80% are large ones for coal transportation. Therefore, pavement load and road capacity have exceed the designed expressway load capacity. At present, semi-rigid base asphalt pavement structure is still widely used for high-grade highway pavement in Inner Mongolia. With years of construction for such pavement structure, a great deal of valuable experience has been gained on construction technology. However, there are still a few deficiencies in the quality of raw materials, gradation control of asphalt mixture and adjustment of equipment, etc. Hohhot circle expressway connects with the G6 and G7 expressways, suffering from problems such as large vehicle flow and load overweight. This paper introduced a key technique that should be properly controlled during construction of such pavement structure, emphasized technique control and management of the following aspects, i.e. ballast sizes and gradation control, asphalt concrete mixture, adjustment of pavers, validation of mixing proportion in production and reasonable arrangement of process, and summarized corresponding technical measures taken during construction of asphalt pavement in this project.

Mechanical Response Analysis of the Composite Asphalt Pavement

2014 ◽  
Vol 1023 ◽  
pp. 28-31
Author(s):  
Li Min Li
Keyword(s):  
Service Life ◽  
Mechanical Response ◽  
Asphalt Pavement ◽  
Road Construction ◽  
Pavement Design ◽  
Rigid Base ◽  
Response Analysis ◽  
Early Failure ◽  
Short Service Life ◽  
Design Software

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.

Analysis of Performance Decay Behavior for Asphalt Pavement Based on Aging

2013 ◽  
Vol 723 ◽  
pp. 22-26 ◽  
Author(s):  
Pei Long Li ◽  
Zhan Ding ◽  
Zheng Qi Zhang
Keyword(s):  
Shear Stress ◽  
Service Life ◽  
Tensile Stress ◽  
Simulation Analysis ◽  
Asphalt Pavement ◽  
Maximum Shear Stress ◽  
Maximum Tensile Stress ◽  
Pavement Structure ◽  
Analysis Of Performance ◽  
Decay Behavior

Aging is a main factor affecting the durability of asphalt pavement. To study decay behavior of asphalt pavement with aging, aged asphalt was extracted from stratified pavement mixtures for different service-life. The changes of asphalt properties with service time and depth variations of the pavement were discussed. And numerical simulation analysis of pavement structure was conducted with pavement gradient modulus changes caused by aging. The results indicate that asphalt stiffness increases and low-temperature performance decays sharply with the extension of pavement service life, especially in the first several years. The vertical aging differences from top to bottom of pavement were significant, the aging extents decrease continuously from the surface, which cause the gradient changes of pavement modulus. The maximum tensile stress and maximum shear stress all increase with surface modulus increasing, so more serious aging can induce greater gradient modulus, shear stress and tensile stress are larger under the same loads, which have more serious damage to the pavement structure.

Influence of Strength Attenuation for Silt Soil on the Fatigue Life of Semi-Rigid Base

2013 ◽  
Vol 353-356 ◽  
pp. 120-124
Author(s):  
Xiao Ming Yi ◽  
Song Gen Wang ◽  
Xiu Guang Song ◽  
Zhen Qing Liu
Keyword(s):  
Fatigue Life ◽  
Water Content ◽  
Yellow River ◽  
Asphalt Pavement ◽  
Rigid Base ◽  
Influence Of Water ◽  
Design Value ◽  
The Difference ◽  
Early Damage ◽  
Resilience Modulus

Influence of water content on the resilience modulus for silt soil in Yellow River alluvial plane is studied by laboratory tests. And its found that resilience modulus decrease dramatically when the water content exceeds the optimum. So the subgrade cant support the pavement structure enough, which could make the fatigue life of semi-rigid base little than the design value. Basing on the distribution of the water content in real, the silt subgrade is divided into three parts in accordance with the difference of resilience modulus. Then, the tensile stress and fatigue life of semi-rigid base is gotten, and results show the strength decay of subgrade reduced the fatigue life of semi-rigid base up to 50%, which exposes the causes of early damage of semi-rigid base asphalt pavement on silt subgrade.

Coupled Numerical Analysis of the Anti-Crack Mechanism for Open-Graded Large Stone Asphalt Mixes

2009 ◽  
Vol 79-82 ◽  
pp. 1149-1152
Author(s):  
Hong Bing Guo ◽  
Shuan Fa Chen
Keyword(s):  
Finite Element ◽  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Rigid Base ◽  
Reflective Cracking ◽  
Large Stone ◽  
Concrete Base ◽  
Test Road ◽  
Cracking Performance ◽  
Pavement Structure

The reflective cracking in asphalt surface is a technical problem that exists in the semi-rigid base asphalt pavement structure and the rigid base asphalt pavement structure, how to control its emergence and development is still a major problem for road engineering. At present, researches on the anti-cracking performance for Open-graded Large Stone asphalt Mix (OLSM) in China almost remain in the test road observations, very few study the mechanism of its anti-cracking from the mechanical point. Aiming at this problem, a method of using OLSM as the cracking relief layer is proposed, large mineral aggregate, low asphalt content and a great deal of void in OLSM can dissipate or absorb stress and strain around the crack. The 3-D finite element method is used to analyze the crack-alleviating layer of ordinary asphalt concrete and OLSM, and the large-scale commercial finite element software of ABAQUS is used to do numerical simulation analysis for the lean concrete base asphalt pavement structure with OLSM, the analysis result indicates that temperature-load coupling stress of OLSM are less than that of ordinary asphalt concrete. Depending on the test road on an expressway, research on the anti-crack mechanism of OLSM has been conducted. The investigation of the test road and the result of the theoretical calculation indicate that OLSM can prevent lean concrete base asphalt pavement from the reflective cracking effectively, OLSM has good anti-cracking performance, it is an effective material to alleviate the reflective cracking. As the crack-alleviating layer, OLSM can significantly enhance the anti-cracking ability of the semi-rigid base asphalt pavement structure and the rigid base asphalt pavement structure.

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