Stress Characteristic Analysis of Repaving Asphalt Pavement Structure on Old Cement Road

2012 ◽  
Vol 594-597 ◽  
pp. 1377-1381 ◽  
Author(s):  
Hong Lu Mao ◽  
Pei Zhi Zhuang ◽  
Ya Nan Zang ◽  
Xiao Ming Yi
Keyword(s):  
Shear Stress ◽  
Compressive Stress ◽  
Asphalt Pavement ◽  
Rigid Base ◽  
Cement Concrete ◽  
Characteristic Analysis ◽  
Finite Element Software ◽  
Splitting Failure ◽  
Cement Concrete Pavement ◽  
Pavement Structure

To solve the early destruction problems occurred when overlaying asphalt pavement structure containing semi-rigid base on broken cement concrete pavement, finite element software is used to compare the stress characters between the repaving pavement and ordinary pavement, and analyze the repaving structures under different loads and different road transverse grade. It shows that the value of compressive stress at the top of base of repaving pavement is significantly higher than that of ordinary pavement, meanwhile, its value of tensile stress of base bottom is lower; the asphalt surface and new base top of repaving pavement need to bare a high value of shear stress and compressive stress under overload, so it’s prone to splitting failure in the base. With the increase of transverse grade, both the shear stress difference of road surface and maximum vertical compressive at top of the base increase in a lower position, but the situation is opposite in the higher position.

Influences on the Axle Load Stress of the Cement-Concrete Pavement Structure Caused by the Crack or Cutting Crack of the Semi-Rigid Base

2013 ◽  
Vol 857 ◽  
pp. 200-203
Author(s):  
Bin Yang ◽  
Hua Tan ◽  
Jia Xi Deng ◽  
Chan Pang
Keyword(s):  
Working Conditions ◽  
Crack Width ◽  
Concrete Pavement ◽  
Rigid Base ◽  
Cement Concrete ◽  
3D Fem ◽  
Cement Concrete Pavement ◽  
Dry Shrinkage ◽  
Pavement Structure ◽  
The One

Some horizontal cracks will appear during the strength formation of the semi-rigid base, for the influences of dry shrinkage and temperature shrinkage exist, so the engineers often adopt the manual method of equidistant cutting crack to avoid the irregular cracks. In order to analyse the influences on the axle load stress of the cement-concrete pavement slab which caused by the width and position of the base cracks or cutting cracks, the 3D FEM was used to study them under the different working conditions considering the crack, width and position. By the above research, the results show the existing cracks affect the integrity and continuity of the pavement structure; The crack width has no large influence on the stress of the pavement slab, while the base stress decreases apparently with the increasing width, and it becomes stable finally; The stress of the pavement slab is maximum when the crack or cutting crack is located in the middle, while it's small when the crack or cutting crack is located in the one fourth of the pavement slab.

Dynamic Response of Asphalt Pavement on Semi-Rigid Base due to Heavy Load

2013 ◽  
Vol 405-408 ◽  
pp. 1745-1752
Author(s):  
Li Juan Zhang
Keyword(s):  
Shear Stress ◽  
Surface Layer ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Asphalt Pavement ◽  
Road Surface ◽  
Rigid Base ◽  
Heavy Load ◽  
Vertical Strain ◽  
Surface Deflection

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.

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.

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.

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.

Mechanism Analysis of Rutting at Urban Intersections Based on Numerical Simulation of Moving Loads

2010 ◽  
Vol 152-153 ◽  
pp. 1192-1198 ◽  
Author(s):  
Ze Jiao Dong ◽  
Zong Jie Sun ◽  
Xiang Bing Gong ◽  
Hao Liu
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Asphalt Pavement ◽  
Moving Load ◽  
Maximum Shear Stress ◽  
Uniform Motion ◽  
Dynamic Mode ◽  
Mechanism Analysis ◽  
Horizontal Shear ◽  
Pavement Structure

Frequent starting and braking of vehicles causes rutting of asphalt pavement at urban intersection. As a result, dynamic response of pavement subjected to these kinds of vehicle loadings can be used to analyze rutting mechanism. At first, vehicle loading at urban intersection was described by a vertical and horizontal combined moving pressure with variable speeds. Then, three-dimensional finite element model in transient dynamic mode is developed based on the practical pavement structure. And the moving load, boundary conditions and material parameters were briefly introduced. Finally, through the comparison of time histories and spatial distribution among accelerating, decelerating and uniform motion, mechanism of rutting of asphalt pavement at urban intersections was illustrated according to the finite element simulation. It shows that frequent starting and braking of vehicle at urban intersections, obviously change the stress distribution within pavement structure compared with uniform motion case. The distribution and amplitude of maximum shear stress and horizontal shear stress was observed during the passage of the loading, which will result in shear flow deformation. Pavement structure subjected to moving load exhibits an alternative characteristic which will accelerate the rutting damage of pavement.

Stress Analysis for Cement Concrete around Joint Dowel after Loosing

2013 ◽  
Vol 857 ◽  
pp. 222-226
Author(s):  
Rong Guo Hou ◽  
Kai Min Niu
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Load Transfer ◽  
Concrete Slab ◽  
Concrete Pavement ◽  
Cement Concrete ◽  
Transfer Capability ◽  
Cement Concrete Pavement ◽  
Contraction Joint ◽  
Increasing Load

The stress concentration will appear in cement concrete around joint dowel set in contraction joint of cement concrete pavement with repeated loads. And concrete around joint dowel will damage gradually.In this paper, the stress of concrete around joint dowel and deflection of concrete slab are analyzed when joint dowel loosing. It is indicated that the shear stress is key to damage of concrete around joint dowel. when the loosing width reaches certain extent. With loosing width increasing, load transfer capacity will decrease gradually. And it is shown that the load transfer capability will lower rapidly when the loosing width comes in 4cm.

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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