Effects of subbase geogrid reinforcement on residual deformation characteristics of asphalt pavement

2012 ◽  
pp. 474-479 ◽  
Author(s):  
D Hirakawa ◽  
Y Miyata
Keyword(s):  
Asphalt Pavement ◽  
Residual Deformation ◽  
Deformation Characteristics ◽  
Geogrid Reinforcement

scholarly journals The Influence of the Carbo-Glass Geogrid-Reinforcement on the Fatigue Life of the Asphalt Pavement Structure / Wpływ Zbrojenia Siatka Weglowo–Szklana Na Trwałosc Zmeczeniowa Asfaltowej Nawierzchni Drogowej

2012 ◽  
Vol 58 (1) ◽  
pp. 97-113 ◽  
Author(s):  
J. Górszczyk ◽  
S. Gaca
Keyword(s):  
Fatigue Life ◽  
Asphalt Pavement ◽  
Field Tests ◽  
Traffic Loading ◽  
Geogrid Reinforcement ◽  
Traffic Conditions ◽  
Pavement Structure ◽  
Number Of Cycles ◽  
The One ◽  
Stress Fatigue

Abstract This paper describes the analyses of the fatigue life of the asphalt pavement reinforced with geogrid interlayer under traffic loading. Finite Element ANSYS package with using nCode applications, as well as macros specially designed in APDL programming script and VBA were used to model the considered problem. Our analysis included computation of stress, fatigue life, damage matrix and rainflow matrix. The method applied was the one of fatigue calculation: stress - number of cycles in short S-N. On the basis of the performed high cycle fatigue analysis, the influence of the location of the used geogrid and of its bond with asphalt layers on the fatigue life and the work of the asphalt pavement structure were determined. The study was carried out for three temperature seasons i.e. spring and fall (assumed as one season), winter and summer. The variability of the traffic conditions were taken into account by assuming weekly blocks of traffic loading. The calculations were made using the real values of loading measured in field tests on the German highways by means of HS-WIM weighing system. As a result of the performed tests, it was proved that the use of geogrid-reinforcement may prolong the fatigue life of the asphalt pavement. However, it is required that: the geogrid should be located in the tension zone as low as possible in the structure of the asphalt layers. Moreover, it is necessary to provide high stiffness of the bond between the geogrid and the asphalt layers.

scholarly journals Long Term Behaviour of An Asphalt Pavement Structure Constructed on a Geogrid-Reinforced Subgrade Over Soft Soils

2019 ◽  
Vol 14 (3) ◽  
pp. 384-404
Author(s):  
Aurimas Šiukščius ◽  
Viktoras Vorobjovas ◽  
Audrius Vaitkus ◽  
Šarūnas Mikaliūnas ◽  
Atis Zariņš
Keyword(s):  
Load Transfer ◽  
Asphalt Pavement ◽  
Soft Soil ◽  
Soft Soils ◽  
Geogrid Reinforcement ◽  
The Road ◽  
Road Pavement ◽  
On The Road ◽  
Term Performance

Many roads with asphalt pavement are being reconstructed every year, as their quality becomes insufficient by the requirements. As it is well- known, old roads were built not in the very best quality, so doing reconstruction projects in the most cases there were required to deal with soft soils that are under the existing road structure. Geogrid reinforcement was widely used to solve issues of soft soil in Lithuania. There are projects where geogrid reinforcement is used to control road pavement roughness when there are layers of peat or silt under road structure instead of using concrete piles or geosynthetic-encased soil columns. This type of geogrid reinforcement application is unexplained in any normative-technical document but widely used in Lithuania. This application was usually made constructively without any calculations, choosing the reinforced solution by reducing the geogrid tensile strength or layer quantity compared to reinforced load transfer platform over piles. This paper evaluates the long-term influence of geogrid- reinforced subgrade on the roughness of asphalt surfacing and bearing capacity of the road structure when the soft peaty soils stratify in the deeper layers of the subgrade. There were compared the reinforced sections to adjacent sections to see the effect and fortunately a large number of adjacent sections were also strengthened, mostly by lime stabilisation. Therefore, this comparison allows making more insights on the long-term performance of the strengthened subgrade and influence on the road quality. This research gives recommendations on how the geogrids has to be selected to be used in this kind of application.

scholarly journals FIELD TEST ON CONFINED-REINFORCED EARTH METHOD USING GEOGRID REINFORCEMENT FOR ASPHALT PAVEMENT

2012 ◽  
Vol 27 (0) ◽  
pp. 89-92 ◽  
Author(s):  
Shinichiro TSUJI ◽  
Naoki TATTA ◽  
Tsutomu ISHIGAKI ◽  
Hideki OHTA
Keyword(s):  
Field Test ◽  
Asphalt Pavement ◽  
Geogrid Reinforcement ◽  
Reinforced Earth

Investigation of shock-wave deformation history from recovered structure

1986 ◽  
Vol 44 ◽  
pp. 434-435
Author(s):  
M.A. Mogilevsky ◽  
L.S. Bushnev
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Shock Waves ◽  
Shock Front ◽  
Single Crystals ◽  
Residual Deformation ◽  
Deformation Structure ◽  
Deformation History ◽  
Deformation Velocity

Single crystals of Al were loaded by 15 to 40 GPa shock waves at 77 K with a pulse duration of 1.0 to 0.5 μs and a residual deformation of ∼1%. The analysis of deformation structure peculiarities allows the deformation history to be re-established.After a 20 to 40 GPa loading the dislocation density in the recovered samples was about 1010 cm-2. By measuring the thickness of the 40 GPa shock front in Al, a plastic deformation velocity of 1.07 x 108 s-1 is obtained, from where the moving dislocation density at the front is 7 x 1010 cm-2. A very small part of dislocations moves during the whole time of compression, i.e. a total dislocation density at the front must be in excess of this value by one or two orders. Consequently, due to extremely high stresses, at the front there exists a very unstable structure which is rearranged later with a noticeable decrease in dislocation density.

Transmission Electron Microscopic Observations of Al3Li and Al3Ti Precipitation in A Rapidly Solidified Al-3Li-0.2Ti ALLOY

1980 ◽  
Vol 38 ◽  
pp. 336-337
Author(s):  
J. E. O’Neal ◽  
K. K. Sankaran ◽  
S. M. L. Sastry
Keyword(s):  
Rapid Solidification ◽  
Metallic Substrate ◽  
Deformation Characteristics ◽  
Phase Decomposition ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Supersaturated Solid Solutions ◽  
Transmission Electron Microscopic ◽  
Rapidly Solidified ◽  
Microstructural Homogeneity

Rapid solidification of a molten, multicomponent alloy against a metallic substrate promotes greater microstructural homogeneity and greater solid solubility of alloying elements than can be achieved by slower-cooling casting methods. The supersaturated solid solutions produced by rapid solidification can be subsequently annealed to precipitate, by controlled phase decomposition, uniform 10-100 nm precipitates or dispersoids. TEM studies were made of the precipitation of metastable Al3Li(δ’) and equilibrium AL3H phases and the deformation characteristics of a rapidly solidified Al-3Li-0.2Ti alloy.

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