Correction Factor of Surface Deflection for Inverted Asphalt Pavement Based on Linear-Anisotropy

2011 ◽  
Vol 255-260 ◽  
pp. 3311-3315
Author(s):  
Zhen Feng Li ◽  
Xiang Yun Guo ◽  
Ming Zhang
Keyword(s):  
Granular Material ◽  
Correction Factor ◽  
Asphalt Pavement ◽  
Practical Application ◽  
Material Anisotropy ◽  
Current Design ◽  
Surface Deflection ◽  
The Common ◽  
Different Thickness ◽  
Isotropic Theory

Inverted asphalt pavement has been widely used in practical application. Anisotropy of granular material has been proved by experiment, but the current design specifications are also based on isotropic theory. Based on linear-anisotropic model, on the condition of the high, medium and low strength of soil subgrade, 4 different thickness of asphalt layer and 3 different thickness of granular sandwich are been systematically studied, the results show that, the strength of the soil subgrade has bigger effect on the pavement deflection, the deflection difference of the low to the high subgrade is about 14~23%, with the increase of granular material anisotropy, the deflection correction factor is bigger, with the granular sandwich anisotropic rates from 0.1 to 0.5, the deflection correction factor is within 1.04, the thin asphalt layer and the thick granular sandwich have bigger effect on the deflection correction factor, for the common inverted asphalt pavement structure, the proposed deflection correction factor is 1.02~1.04, it can be used directly in asphalt pavement design.

Green Design and Manufacturing Technology on Hoisting Device of the Silt Coal Car Loader

2011 ◽  
Vol 328-330 ◽  
pp. 220-223
Author(s):  
Ping Huai Mao ◽  
Run Dong Chen ◽  
Bing Zhai
Keyword(s):  
Science And Technology ◽  
Manufacturing Technology ◽  
Design Concept ◽  
Green Design ◽  
Practical Application ◽  
Working Process ◽  
Manufacturing Technique ◽  
Design And Manufacturing ◽  
The Common ◽  
Working Device

This paper analyzes the common faults of the YMZ light silt coal car loader's hoisting device in working process, and supplies several solutions; Simultaneously, it mainly introduces two types of manufacturing technique about hoisting device's parts design and improvement in practical application and appraises the effect of the green design and manufacturing technique in the working device; The article concludes that improved workpiece performance is of great practical value; As the designers are designing the products, only when they should combine the new design concept and the mode of thinking with the green design concept, and attach importance to the innovation of science and technology during the designing process as well, and finally bring into play the advantages of the technology, can they produce safe, powerfrugal, efficient and shapely green products which are popular with people at home and abroad.

scholarly journals Construction Treatment Technology for Cracks in Asphalt Pavement of Road and Bridge

2020 ◽  
Vol 198 ◽  
pp. 03013
Author(s):  
Yueshu Li
Keyword(s):  
Service Life ◽  
Influencing Factors ◽  
Road Traffic ◽  
Asphalt Pavement ◽  
Construction Technology ◽  
Treatment Technology ◽  
The Common

In recent years, with the development of road traffic in China, road and bridge projects have gradually increased. While the number of projects has increased sharply, construction technology has been greatly improved. The increase in the use of roads and bridges has led to an increase in the probability of cracks on the roads and bridges. Starting from the common types of cracks, this article explains how to effectively ensure the service life of roads and bridges, improve the performance of roads and bridges, avoid road cracks, deal with the cracks, and emphasize the influencing factors of cracks and the corresponding solutions for the reference of relevant personnel.

Anisotropic Creep Behaviour of Bridgman Notch Specimens

2005 ◽  
Vol 219 (3) ◽  
pp. 163-175 ◽  
Author(s):  
T H Hyde ◽  
I A Jones ◽  
S Peravali ◽  
W Sun ◽  
J G Wang ◽  
...  
Keyword(s):  
Cross Section ◽  
Bulk Material ◽  
Creep Behaviour ◽  
Practical Application ◽  
Material Anisotropy ◽  
Yield Model ◽  
Anisotropic Parameter ◽  
Creep Analysis ◽  
Minimum Cross Section ◽  
Anisotropic Creep

A series of finite element anisotropic creep analyses of a Bridgman notch specimen have been performed. The anisotropic creep analysis is based on Hill's anisotropic yield model and the Norton creep law. An anisotropic parameter, p, is defined in order to quantify the degree of bulk material anisotropy which exists in a weld metal. The effects of p and the Norton stress exponent, n, on the stationary-state stresses, at the minimum cross-section of the notch, are presented. The material constants were chosen to include the practical range for engineering materials. Indications of the practical application of anisotropic analyses to welds are given.

An Application of Time Classification in the System Maintenance Allocation

2012 ◽  
Vol 251 ◽  
pp. 91-96
Author(s):  
Yong Xiang Li ◽  
Ying Li ◽  
Chuan Lv
Keyword(s):  
Practical Application ◽  
Maintenance Time ◽  
System Maintenance ◽  
The Common ◽  
Mean Time To Repair ◽  
Improved Model ◽  
Mean Time ◽  
Allocation Methods

The aim of the maintenance allocation is to allocate the maintenance time of the subsystems reasonably and accurately. Traditional MTTR (mean time to repair) allocation methods are most often based on the products’ complexity. However, there are a lot of deficiencies in practical application. To allocate the system MTTR of the subsystems more precise and reasonable, a better model is needed. The aim of this paper is to develop an improved model to allocate the maintenance time, as well as picke out the common maintenance time and allocating e the MTTR in the subsystems more accurately.

scholarly journals What Is Performance? A Scoping Review of Performance Outcomes as Study Endpoints in Athletics

Sports ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 66 ◽  
Author(s):  
Benjamin Raysmith ◽  
Jenny Jacobsson ◽  
Michael Drew ◽  
Toomas Timpka
Keyword(s):  
Qualitative Analysis ◽  
Scoping Review ◽  
Performance Metrics ◽  
Data Extraction ◽  
Selection Procedure ◽  
Performance Outcomes ◽  
Practical Application ◽  
Performance Metric ◽  
The Common ◽  
Future Direction

Purpose: This review set out to summarise, define, and provide future direction towards the use of performance outcome measures as endpoints in research performed at international benchmark events in athletics. Methods: Scoping review methodology was applied through a search of the PubMed and Sports Discus databases and a systematic article selection procedure. Articles that met the inclusion criteria underwent triage for further quantitative and qualitative analysis. A concept chart was generated to describe the methods by which performance had been measured and introduce descriptive labels for theoretical and practical application. Results: None of 2972 articles primarily identified from the database search met the triage standards for quantitative data extraction. Eleven articles were included in a qualitative analysis. The analysis identified the common methods by which performance has been measured, reported and analysed. The resulting concept chart collates labels from the qualitative analysis (categories, themes, and constructs) with sports practice labels (performance metrics, framework, and analysis). Conclusions: The state of knowledge concerning methods to employ performance metrics as endpoints in studies performed at major competitions in athletics has been summarised. Constructing a methodology that combines the performance metric variables (continuous and ordinal) that are currently utilised as endpoints remains a challenge.

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.

scholarly journals Investigation on the Combined Effect of Fibers and Cement on the Mechanical Performance of Foamed Bitumen Mixtures Containing 100% RAP

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ehsan Ashouri Taziani ◽  
Emanuele Toraldo ◽  
Filippo Giustozzi ◽  
Maurizio Crispino
Keyword(s):  
Research Study ◽  
Mechanical Performance ◽  
Asphalt Pavement ◽  
Construction Materials ◽  
Recycled Asphalt ◽  
New Methods ◽  
Dynamic Creep ◽  
Indirect Tensile ◽  
The Common ◽  
Foamed Bitumen

Concerns about virgin aggregate sources and increasing demands for construction materials of transport infrastructures as the key parameters in development are the most important reasons, which convinced pavement engineers to develop new methods in order to use higher amount of recycled asphalt pavement (RAP). One of the common methodologies to produce mixtures containing RAP is foamed bitumen mix (FBM). In addition, according to previous research studies, incorporating various types of fibers and hydraulic binders such as cement could significantly improve the mechanical performance of mixtures. The present research study evaluated FBM containing 100% RAP and two types of fiber and Portland cement. Dynamic modulus, unconfined dynamic creep compression, and indirect tensile strength were evaluated in the laboratory at optimum moisture content, which was investigated in this research. Both types of fiber and cement proved to enhance specific properties of mixtures.

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