scholarly journals Equivalent temperature for design of asphalt pavements in Poland

2019 ◽  
Vol 262 ◽  
pp. 05010 ◽  
Author(s):  
Marek Pszczola
Keyword(s):  
Design Process ◽  
Asphalt Pavement ◽  
Climatic Conditions ◽  
Design Methods ◽  
Pavement Design ◽  
Asphalt Pavements ◽  
Climatic Data ◽  
Equivalent Temperature ◽  
Calculation Methods

The paper presents application of equivalent temperature for design of asphalt pavements. The calculation methods of equivalent temperature: the Shell method, the French method, the methods that use the AASHTO and the Asphalt Institute fatigue criteria were presented. The results of calculations of equivalent temperature for Polish climatic conditions were presented and discussed. It was shown that different asphalt pavement design methods and utilization of Polish climatic data resulted in various calculated values of equivalent temperature that could be used in the design process.

Impaction of Climate Change on Asphalt Pavements

2013 ◽  
Vol 723 ◽  
pp. 617-622
Author(s):  
Er Hu Yan ◽  
Fu Pu Li ◽  
Rong Ma ◽  
Fei Chen
Keyword(s):  
Climate Change ◽  
Heat Wave ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Climatic Conditions ◽  
Extreme Heat ◽  
Asphalt Pavements ◽  
Asphalt Cement ◽  
The Past ◽  
Change Climate

Climate change is one of the most key global topics well-known in international community. Over the past decades years, the change climate and its impact on asphalt pavement in China is very obvious. Many expressways of asphalt pavement come forth severe rutting failure during only a few days of extensive, long-lasting, extreme heat wave in summer, which resulting in the change of asphalt cement specification and the selection practice of asphalt cement. So it is necessary to review climate change and its impact in the past, and forecast the probable situation in the future. The paper focuses specifically on the issue of asphalt binder selection under changing climatic conditions.

scholarly journals The Impact of Heavy Vehicle Traffic Trends on the Overdesign of Flexible Asphalt Pavements

2020 ◽  
Vol 12 (7) ◽  
pp. 2688
Author(s):  
Paolo Intini ◽  
Nicola Berloco ◽  
Pasquale Colonna ◽  
Vittorio Ranieri
Keyword(s):  
Cost Benefit ◽  
Design Methods ◽  
Pavement Design ◽  
Asphalt Pavements ◽  
Heavy Vehicle ◽  
Traffic Data ◽  
Heavy Vehicles ◽  
Vehicle Traffic ◽  
Traffic Volumes ◽  
The Impact

Given their environmental impact, the careful design of asphalt pavements is crucial. Previous research has highlighted the influence of several parameters on the outputs of different pavement design methods. In this study, the focus is on heavy vehicle trends, considering both the percentage of heavy vehicles in the average traffic flow and its evolution over time, which is usually included as a growth factor in the design inputs. Since these factors are very often assumed to be based on old estimates, the first aim of this study was to update them by exploring a recent series of continuous data collected on the Italian motorway network and showing how to infer estimates from historical traffic data. Subsequently, the variability of these input factors is introduced in standard pavement design methods to assess their influence on the design process and to quantify the risk of overdesign. While the analysis of historical heavy vehicle traffic data may reveal an overall zero-growth traffic tendency, different scenarios should be considered and assessed in cost-benefit analyses given the not negligible influence of growth factors on pavement thicknesses. This influence is shown here in different simulated design conditions, with different initial traffic volumes, share of heavy vehicles, and resilient moduli.

scholarly journals Comparative Study of French and Chinese Asphalt Pavement Design Methods

2015 ◽  
Vol 15 (6) ◽  
pp. 923-928 ◽  
Author(s):  
Pierre Guy Atangana Njock ◽  
Li Yueguang
Keyword(s):  
Comparative Study ◽  
Asphalt Pavement ◽  
Design Methods ◽  
Pavement Design

scholarly journals Research on Application of Chinese Codes in Asphalt Pavement Design of French Speaking Countries

2021 ◽  
Vol 719 (3) ◽  
pp. 032076
Author(s):  
En-kuan Tang ◽  
Kang Cai ◽  
Lian-feng Qu ◽  
Run-yao Zhang ◽  
Peng Zhang
Keyword(s):  
Asphalt Pavement ◽  
Pavement Design ◽  
French Speaking ◽  
Research On Application

Impact of Secondary Flow on the Accuracy of Simplified Design Methods for Steam Turbine Stages

2012 ◽  
Author(s):  
Jan Schumann ◽  
Ulrich Harbecke ◽  
Daniel Sahnen ◽  
Thomas Polklas ◽  
Peter Jeschke ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Steam Turbine ◽  
Design Process ◽  
Design Method ◽  
Computing Time ◽  
Leading Edge ◽  
Design Methods ◽  
Preliminary Design ◽  
Line Design ◽  
Radial Equilibrium

The subject of the presented paper is the validation of a design method for HP and IP steam turbine stages. Common design processes have been operating with simplified design methods in order to quickly obtain feasible stage designs. Therefore, inaccuracies due to assumptions in the underlying methods have to be accepted. The focus of this work is to quantify the inaccuracy of a simplified design method compared to 3D Computational Fluid Dynamics (CFD) simulations. Short computing time is very convenient in preliminary design; therefore, common design methods work with a large degree of simplification. The origin of the presented analysis is a mean line design process, dealing with repeating stage conditions. Two features of the preliminary design are the stage efficiency, based on loss correlations, and the mechanical strength, obtained by using the beam theory. Due to these simplifications, only a few input parameters are necessary to define the primal stage geometry and hence, the optimal design can easily be found. In addition, by using an implemented law to take the radial equilibrium into account, the appropriate twist of the blading can be defined. However, in comparison to the real radial distribution of flow angles, this method implies inaccuracies, especially in regions of secondary flow. In these regions, twisted blades, developed by using the simplified radial equilibrium, will be exposed to a three-dimensional flow, which is not considered in the design process. The analyzed design cases show that discrepancies at the hub and shroud section do exist, but have minor effects. Even the shroud section, with its thinner leading-edge, is not vulnerable to these unanticipated flow angles.

Review on Renewable Energy Potential in Australian Subtropical Region (Central and North Queensland)

2011 ◽  
Vol 347-353 ◽  
pp. 3846-3855 ◽  
Author(s):  
Ali Baniyounes ◽  
Gang Liu ◽  
M. G. Rasul ◽  
M. M. K. Khan
Keyword(s):  
Renewable Energy ◽  
Wind Speed ◽  
Spatial Databases ◽  
Cost Effective ◽  
Climatic Conditions ◽  
Energy Resources ◽  
Climatic Data ◽  
Renewable Energy Resources ◽  
Subtropical Region ◽  
Energy Potential

In Australia the future demand for energy is predicted to increase rapidly. Conventional energy resources soaring prices and environmental impact have increased the interest in renewable energy technology. As a result of that the Australian government is promoting renewable energy; such as wind, geothermal, solar and hydropower. These types of energy are believed to be cost-effective and environmentally friendly. Renewable energy availability is controlled by climatic conditions such as solar radiation, wind speed and temperature. This paper aims to assess the potential of renewable energy resources, in particular wind and solar energy in an Australian subtropical region (Central and North Queensland) namely, Gladstone, Emerald, Rockhampton, Yeppoon, Townsville, and Cairns. Analysis is done by using the latest statistical state of Queensland energy information, along with measured data history of wind speed, solar irradiations, air temperature, relative humidity, and atmospheric pressure for those sites. This study has also shown that national assessments of solar and wind energy potential can be improved by improving local climatic data assessments using spatial databases of Central and North Queensland areas.

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.

Study on Load Stress of Lean Concrete Base in Asphalt Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1495-1498
Author(s):  
Li Jun Suo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Asphalt Pavement ◽  
Element Model ◽  
Pavement Design ◽  
The Other ◽  
Three Dimension ◽  
Traffic Loading ◽  
Concrete Base

Load stress, which is caused by traffic loading, is important parameter used in the analysis of the new pavement design. In order to study the load stress of lean concrete base in the asphalt pavement, first of all, three–dimension finite element model of the asphalt pavement is established. The main objectives of the paper are investigated. One is calculation for load stress of lean concrete base, and the other is analysis for relationship between load stress of lean concrete base and parameters, such as thickness, modulus. The results show that load stress of lean concrete base decreases, decreases and increases with increase of base’s thickness, surface’s thickness and ratio of base’s modulus to foundation’s modulus respectively. So far as the traffic axle loading is concerned, it has a significant impact on load stress of lean concrete base, and it can be seen from results that when load is taken from 100kN to 220kN, load stress increases quickly with the increase of the traffic axle loading.

scholarly journals Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Pederzani ◽  
Vera Aldeias ◽  
Harold L. Dibble ◽  
Paul Goldberg ◽  
Jean-Jacques Hublin ◽  
...  
Keyword(s):  
Human Behavior ◽  
Late Pleistocene ◽  
Tooth Enamel ◽  
Climatic Conditions ◽  
Climatic Data ◽  
Human Scale ◽  
Winter Temperatures ◽  
Archaeological Materials ◽  
Climatic Records

AbstractExploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.

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