scholarly journals Evaluation of the Coordination of Structural Layers in the Design of Asphalt Pavement

2020 ◽  
Vol 10 (9) ◽  
pp. 3178
Author(s):  
Hao Li ◽  
Naren Fang ◽  
Xuancang Wang ◽  
Chuanhai Wu ◽  
Yang Fang
Keyword(s):  
Structural Design ◽  
Asphalt Pavement ◽  
Material Design ◽  
Evaluation Index ◽  
Area Index ◽  
Test Road ◽  
Actual Use ◽  
Pavement Structure ◽  
Low Efficiency ◽  
Structural Layer

The purpose of asphalt pavement structural design is to get a materially-coordinated and structurally-durable product, and a pavement structure with good road performance by combining the structural layer materials reasonably. However, due to lack of a rational evaluation index on the parameter combinations of structural layer materials, the structural layer materials are poor in terms of coordination, have low efficiency, and the actual use period is much lower than the designed working life. Therefore, it is very important to conduct research evaluating the coordination of the structural layer materials. In this study, the sensitivity of mechanical parameters and equivalent envelope area are proposed as new indexes to evaluate the coordination of material design of asphalt pavement structure layers. Software is developed to calculate the equivalent envelope area that can quantitatively evaluate the coordination among different layers and visualize the mechanical transfer behavior of each structural layer. Based on the equivalent envelope area index, this study incorporates two new steps in the design of pavements, namely the structural form comparison and optimization, and proposes a new structural design process. Finally, the rationality and reliability of the equivalent envelope area index are verified by presenting fatigue life calculation and field verification in a test road. The results propose a clear evaluation index of the coordination of material design of each structural layer, which makes the structural design of the asphalt pavement more scientific and reasonable.

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.

scholarly journals Modulus Inversion Layer by Layer of Different Asphalt Pavement Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mingming Cao ◽  
Wanqing Huang ◽  
Yiwen Zou ◽  
Guomin Liu
Keyword(s):  
Transition Layer ◽  
Asphalt Pavement ◽  
Structural Characteristics ◽  
Inversion Layer ◽  
Crushed Stone ◽  
Inversion Method ◽  
Layer By Layer ◽  
Pavement Structure ◽  
Pavement Structures ◽  
Structural Layer

In order to improve the accuracy of modulus inversion of the pavement structure layer, a layer-by-layer inversion method was proposed to be compared with the traditional inversion method by inverting the modulus of each structural layer of the inverted asphalt pavement and semirigid asphalt pavement. The results show that the influence of cushion modulus on the modulus of inverted subgrade and modulus of cement-stabilized crushed stone is restricted by the cushion modulus and pavement structure characteristics, and the thicker cement-stabilized crushed stone layer is beneficial for improving inverted modulus of subgrade; besides, for the inverted asphalt pavement, the modulus of the graded crushed stone transition layer has a significant influence on the modulus inversion of cement-stabilized crushed stone. The modulus of the graded gravel transition layer inverted by these two methods is underestimated, the modulus of cement-stabilized gravel is overestimated using the traditional inversion method, and the inversion result of the inverted asphalt pavement is more significantly affected by the inversion method than the semirigid base asphalt pavement. Moreover, the modulus of the pavement structural layer is determined by the material and structural characteristics, and its recommended empirical value or the value in the indoor test does not conform to the actual value of the site; by contrast, the inversion modulus obtained using the layer-by-layer inversion method is closer to the actual value, which can be used in the design of similar pavement structures to accumulate data for determining the material modulus or the pavement structure adjustment coefficient in the pavement structure.

Prediction of Temperature Field of Asphalt Pavement Structure

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Zhizhong Zhao ◽  
Mengchen Li ◽  
Yu Wang ◽  
Wenwen Chen ◽  
Yulong Zhao ◽  
...  
Keyword(s):  
Temperature Field ◽  
Asphalt Pavement ◽  
Pavement Structure

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.

Experimental Investigation on the Effect of Arm Length on Accuracy of Torque Wrench

2016 ◽  
Vol 853 ◽  
pp. 216-220 ◽  
Author(s):  
You Gang Peng ◽  
Yong Wang
Keyword(s):  
Experimental Investigation ◽  
Structural Design ◽  
Bending Moment ◽  
Theoretical Solution ◽  
Calibration Laboratory ◽  
Moment Measurement ◽  
Torque Wrench ◽  
Actual Use ◽  
Good Agreement

Experiments were carried out to investigate the effect of arm length on the accuracy of two typical conventional torque wrenches, namely, setting type torque wrench (STW) and indicating type torque wrench (ITW). The experiment results demonstrate that the measurement values of STW rises rapidly with decreasing arm length while measured torque of ITW shows irrelevant to arm length. Theoretical solution with respect to STW shows quite good agreement with experiment results. Irrelevance of arm length regard to ITW may be attributable to compensation of bending moment measurement due to proper arrangement of circuit and structural design. In order to conduct a proper assessment at a calibration laboratory or ensure its reliability with reference to actual use conditions, a torque wrench should be used by a customer at the loading point as recommended.

Technological Study on Interlayer Bonding of Double-Layer Porous Asphalt Pavement

2013 ◽  
Vol 405-408 ◽  
pp. 1725-1732 ◽  
Author(s):  
Guo Qi Tang ◽  
Dong Wei Cao ◽  
Ke Zhong ◽  
Xiao Qiang Yang
Keyword(s):  
Double Layer ◽  
Asphalt Pavement ◽  
Layer By Layer ◽  
Simulation Experiments ◽  
Porous Asphalt ◽  
One Step ◽  
Bonding Technology ◽  
Pavement Structure ◽  
Technological Study ◽  
Interlayer Bonding

The interlayer bonding of double-layer porous asphalt pavement will show more variations with different construction technologies, such as one-step molding by double-layer (hot on hot) paver, or paving layer by layer (hot on cold) with or without tack coat, and the variations will definitely have influences on pavement structure. Different interlayer technologies are studied in this paper on three levels including simulation experiments on specimen by indoor preparation, calculation of pavement mechanics, and construction of testing road, so that optimal interlayer bonding technology for double-layer porous asphalt pavement is discussed in combination with its effect on permeability.

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