scholarly journals Numerical Model for Calculating the Unstable State Temperature in Asphalt Pavement Structure

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 271
Author(s):  
Naiji Zhang ◽  
Guoxiong Wu ◽  
Bin Chen ◽  
Cong Cao
Keyword(s):  
Numerical Model ◽  
Asphalt Pavement ◽  
Atmospheric Temperature ◽  
Calculation Model ◽  
Measured Data ◽  
Unstable State ◽  
Maximum Deviation ◽  
Unsteady Temperature ◽  
Pavement Materials ◽  
Pavement Structure

In this study, we determined the factors that influence of the temperature on an asphalt pavement by developing a two-dimensional unsteady temperature numerical calculation model using the finite difference method and Matlab. Based on the temperatures obtained by a buried sensor in a construction project, we collected the temperatures at different depths in the pavement structure in real time, and we then compared and analyzed the calculated and measured data. The results showed that the temperature in the asphalt pavement structure was significantly correlated with meteorological factors, such as the air temperature, but it also exhibited obvious hysteresis. Compared with the measured data, the maximum deviation in the numerical model based on the variations in the atmospheric temperature and solar radiation was 3 °C. Thus, it is necessary to effectively optimize the selection of asphalt pavement materials by simulating the temperature conditions in the asphalt pavement structure.

Establishing and Checking the Temperature and Humidity Coupled Model about Asphalt Pavement Structure

2013 ◽  
Vol 423-426 ◽  
pp. 1126-1131
Author(s):  
Bo Wang
Keyword(s):  
Asphalt Pavement ◽  
Coupled Model ◽  
High Accuracy ◽  
Calculation Model ◽  
Predictive Analysis ◽  
Coupled Equations ◽  
Temperature And Humidity ◽  
Key Factor ◽  
Calculation Results ◽  
Pavement Structure

Temperature and humidity of the pavement affected the performance of the pavement structure as the key factor. In this paper, we used the classic migration theory of temperature and humidity, and considered the actual characteristics of the asphalt pavement structure，established a temperature and humidity coupled equations for the asphalt pavement and got the calculation model by discretization，determined the boundary conditions and calculation parameters。Compared the calculation results with the actual results, we found that the model has high accuracy，it was able to meet the requirement of the predictive analysis about internal temperature and humidity of asphalt pavement in the work of researching and designing.

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

Dynamic Mechanical Response Validation of Pavement Structural under Complex Stress State

2010 ◽  
Vol 163-167 ◽  
pp. 1645-1650
Author(s):  
Guo Ping Qian ◽  
Shuai Li ◽  
Li Jun Jiang
Keyword(s):  
Stress State ◽  
Model Calculation ◽  
Mechanical Response ◽  
Structural Response ◽  
Complex Stress ◽  
Calculation Model ◽  
Dynamic Strain ◽  
Response Model ◽  
Dynamic Mechanical ◽  
Pavement Structure

Under the heavy traffic, the stress state of asphalt pavement structure has such a complex change that it is difficult for conventional pavement structural response calculation model to deal with. Therefore, "Pavement structure dynamic mechanical response model under complex stress condition" is established in this paper. Kinds of cases are calculated according to the characteristics of heavy vehicle. Then the FWD deflection test and dynamic strain test are carried out. Finally, the rationality of pavement structural response model calculation model is proved by comparing the test results with the theoretical model calculation results.

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.

Durability of Cement Stabilized Cold-Recycled of Asphalt Pavement Materials

2012 ◽  
Vol 174-177 ◽  
pp. 1188-1192 ◽  
Author(s):  
Lian Yu Wei ◽  
Zhi Yu Guo
Keyword(s):  
Asphalt Pavement ◽  
Base Material ◽  
Road Construction ◽  
Thermal Shrinkage ◽  
Construction Process ◽  
Pavement Materials ◽  
Road Base ◽  
Wide Range ◽  
Dry Shrinkage ◽  
Recycled Material

In recent years, due to the dual pressures of resources and the environment,the clod recycled technology renovation and expansion of the old road and new road construction process increasingly attention increasingly wide range of applications. In this paper, the water stability of the cold recycled materials in asphalt pavement on cement additives, frozen stability, thermal shrinkage resistance, dry Shrinkage thefour indicators of experiments to evaluate its durability, and compared with the typical semi-rigid material. To verify the feasibility of the cold recycled material as road base material.

Reducing the variability of multi-source reclaimed asphalt pavement materials: A practice in China

2021 ◽  
Vol 278 ◽  
pp. 122389
Author(s):  
Jie Gao ◽  
Jiangang Yang ◽  
Di Yu ◽  
Yu Jiang ◽  
Kaiguo Ruan ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Pavement Materials

Response of Asphalt Pavement Structure Layer and Particle Movement Velocity Based on Particle Flow Theory

2021 ◽  
Vol 147 (12) ◽  
Author(s):  
Zhanyou Yan ◽  
Jiahui Liang ◽  
Yongming Bai ◽  
Lipeng Cao ◽  
Guofang Zhao
Keyword(s):  
Asphalt Pavement ◽  
Flow Theory ◽  
Particle Flow ◽  
Particle Movement ◽  
Movement Velocity ◽  
Pavement Structure ◽  
Structure Layer

Full-Scale Experimental Evaluation of the Flood Resiliency of Thin Concrete Overlay on Asphalt Pavements

2021 ◽  
pp. 036119812110615
Author(s):  
Angel Mateos ◽  
John Harvey ◽  
Miguel Millan ◽  
Rongzong Wu ◽  
Fabian Paniagua ◽  
...  
Keyword(s):  
Structural Damage ◽  
Water Saturation ◽  
Critical Time ◽  
Structural Response ◽  
Extreme Weather Events ◽  
Pavement Materials ◽  
Structural Capacity ◽  
Weather Events ◽  
Pavement Structure ◽  
Falling Weight

The capacity to resist flooding is one of the critical challenges of pavement resiliency in locations subject to inundation. Flooding increases moisture contents, which weakens most pavement materials. Although the effect of moisture on the mechanical properties of most pavement materials is reversible, the structural damage caused by trafficking applied on the weakened pavement structure is not. The critical time for structural damage is typically after the flood and before “life-line” pavements have dried back when trucks are bringing in relief supplies and hauling out demolition. This fact, together with the increased occurrence of extreme weather events and sea level rise resulting from climate change, emphasizes the need to better understand the impacts of flooding on identified life-line pavements. This paper evaluates the flooding resiliency of thin concrete overlay on asphalt (COA) pavements by studying the effects that water saturation produces on the pavement structure. The research is based on the structural response and distresses measured in five thin COA sections that were instrumented with sensors and tested with a heavy vehicle simulator (HVS) under flooded conditions. The research shows that the flooding did not produce a noticeable change in the structural capacity of the COA, based on the structural response measured under the loading of the HVS wheel and the falling weight deflectometer, but did result in some structural damage to the asphalt base in some of the sections.

Aeroelastic Analysis of NREL Wind Turbine

2017 ◽  
Author(s):  
Yaozhi Lu ◽  
Fanzhou Zhao ◽  
Loic Salles ◽  
Mehdi Vahdati
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Gas Turbines ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Measured Data ◽  
Forced Response ◽  
Cycle Fatigue ◽  
Aeroelastic Analysis

The current development of wind turbines is moving toward larger and more flexible units, which can make them prone to fatigue damage induced by aeroelastic vibrations. The estimation of the total life of the composite components in a wind turbine requires the knowledge of both low and high cycle fatigue (LCF and HCF) data. The first aim of this study is to produce a validated numerical model, which can be used for aeroelastic analysis of wind turbines and is capable of estimating the LCF and HCF loads on the blade. The second aim of this work is to use the validated numerical model to assess the effects of extreme environmental conditions (such as high wind speeds) and rotor over-speed on low and high cycle fatigue. Numerical modelling of this project is carried out using the Computational Fluid Dynamics (CFD) & aeroelasticity code AU3D, which is written at Imperial College and developed over many years with the support from Rolls-Royce. This code has been validated extensively for unsteady aerodynamic and aeroelastic analysis of high-speed flows in gas turbines, yet, has not been used for low-speed flows around wind turbine blades. Therefore, in the first place the capability of this code for predicting steady and unsteady flows over wind turbines is studied. The test case used for this purpose is the Phase VI wind turbine from the National Renewable Energy Laboratory (NREL), which has extensive steady, unsteady and mechanical measured data. From the aerodynamic viewpoint of this study, AU3D results correlated well with the measured data for both steady and unsteady flow variables, which indicated that the code is capable of calculating the correct flow at low speeds for wind turbines. The aeroelastic results showed that increase in crosswind and shaft speed would result in an increase of unsteady loading on the blade which could decrease the lifespan of a wind turbine due to HCF. Shaft overspeed leads to significant increase in steady loading which affects the LCF behaviour. Moreover, the introduction of crosswind could result in significant dynamic vibration due to forced response at resonance.

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