Cohesive zone fracture modelling of asphalt pavements with applications to design of high-performance asphalt overlays

2017 ◽  
Vol 19 (3) ◽  
pp. 319-337 ◽  
Author(s):  
Eshan V. Dave ◽  
Behzad Behnia
Keyword(s):  
Cohesive Zone ◽  
High Performance ◽  
Asphalt Pavements ◽  
Asphalt Overlays

scholarly journals Effect of Damage Caused by Site Materials on the Performance of Nonwoven Geotextiles Impregnated With Asphalt Emulsions Used on Paving

2020 ◽  
Author(s):  
Mateus A. Lima ◽  
Jefferson Lins da Silva ◽  
Maria L. C. Lopes
Keyword(s):  
Granular Materials ◽  
Polyethylene Terephthalate ◽  
Hydraulic Properties ◽  
High Load ◽  
Asphalt Pavements ◽  
Asphalt Emulsion ◽  
Rapid Setting ◽  
Damage Process ◽  
Asphalt Emulsions ◽  
Asphalt Overlays

A rehabilitation technique for asphalt pavements with geosynthetic is the application of impregnated nonwoven geotextiles between deteriorated and new asphalt overlays. The performance investigation of impregnated geotextiles proves that they are enhancing in mechanical and hydraulic properties. Although, the installation process may cause severe impacts on these materials’ performance. During the installation, the geotextile suffers damage due to the traffic of high load vehicles, as compactors and pavers, and the friction with granular materials found under its layer or poured above it. This paper aims to investigate how the damage caused by granular materials on nonwoven geotextiles impregnated with different asphalt emulsions effect on their strength resistance and permittivity. From two types of nonwoven geotextiles: polypropylene and polyethylene terephthalate, the comparison uses geotextiles in three conditions: not impregnated, impregnated with asphalt emulsion of rapid setting, and impregnated with asphalt emulsion changed by an elastomeric polymer. Part of the samples followed the damage according to ISO 10722 procedure, placed between three different scenarios of granular materials, applying gravel, sand, and clay. After the damage process, the samples were submitted to mechanical and hydraulic properties evaluations.

scholarly journals Use of unconventional aggregates in hot mix asphalt concrete

2014 ◽  
Vol 9 (4) ◽  
pp. 276-282 ◽  
Author(s):  
Viktors Haritonovs ◽  
Janis Tihonovs
Keyword(s):  
Asphalt Concrete ◽  
High Performance ◽  
Steel Slag ◽  
Asphalt Pavements ◽  
Maximum Efficiency ◽  
Concrete Pavements ◽  
Technological Waste ◽  
Laboratory Test Results ◽  
Dynamic Creep ◽  
Wheel Tracking

The study investigates use of dolomite sand waste as filler or/and sand material plus blast oxygen furnace steel slag as fine and coarse aggregate for design of high performance asphalt concrete. Both environmental and economic factors contribute to the growing need for the use of these materials in asphalt concrete pavements. This is particularly important for Latvia, where local crushed dolomite and sandstone do not fulfill the requirements for mineral aggregate in high and medium intensity asphalt pavements roads. Annually 100–200 thousand tons of steel slag aggregates are produced in Latvia. However, it has not been used extensively in asphalt pavement despite of its high performance characteristics. Dolomite sand waste, which is a byproduct of crushed dolomite production, is another widely available polydisperse by-product in Latvia. Its quantity has reached a million of tons and is rapidly increasing. This huge quantity of technological waste needs to be recycled with maximum efficiency. Various combinations of steel slag, dolomite sand waste and conventional aggregates were used to develop asphalt concrete AC 11 mixtures. The mix properties tests include resistance to permanent deformations (wheel tracking test, dynamic creep test) and fatigue resistance. Laboratory test results showed that asphalt concrete mixtures containing steel slag and local limestone in coarse portion and dolomite sand waste in sand and filler portions had high resistance to plastic deformations and good resistance to fatigue failure

scholarly journals Numerical Simulation of Crack Propagation in Flexible Asphalt Pavements Based on Cohesive Zone Model Developed from Asphalt Mixtures

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1278 ◽  
Author(s):  
Pengfei Liu ◽  
Jian Chen ◽  
Guoyang Lu ◽  
Dawei Wang ◽  
Markus Oeser ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Cohesive Zone ◽  
Fracture Behavior ◽  
Cohesive Zone Model ◽  
Mechanical Design ◽  
Design Methods ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Fracture Mechanisms ◽  
Zone Model

To give engineers involved in planning and designing of asphalt pavements a more accurate prediction of crack initiation and propagation, theory-based models need to be developed to connect the loading conditions and fracture mechanisms present in laboratory tests and under traffic loading. The aim of this study is to develop a technical basis for the simulation of fracture behavior of asphalt pavements. The cohesive zone model (CZM) approach was applied in the commercial FE software ABAQUS to analyze crack propagation in asphalt layers. The CZM developed from the asphalt mixtures in this study can be used to simulate the fracture behavior of pavements and further optimize both the structure and the materials. The investigations demonstrated that the remaining service life of asphalt pavements under cyclic load after the initial onset of macro-cracks can be predicted. The developed CZM can, therefore, usefully supplement conventional design methods by improving the accuracy of the predicted stress states and by increasing the quality, efficiency, and safety of mechanical design methods by using this more realistic modeling approach.

scholarly journals High-Performance Sustainable Asphalt Mixtures for High-Volume Traffic Roads in Severe Climates

2020 ◽  
Vol 12 (21) ◽  
pp. 8765
Author(s):  
Fernando Moreno-Navarro ◽  
Francisco Javier Sierra ◽  
Miguel Sol-Sánchez ◽  
M. Carmen Rubio-Gámez ◽  
Manuel Castillo ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
High Performance ◽  
High Volume ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Mechanical Resistance ◽  
Heavy Vehicles ◽  
Bituminous Materials ◽  
Traffic Volumes

This paper summarizes the work carried out in a research project whose main objective was to develop high-performance sustainable bituminous materials (using crumb rubber and additives to reduce their manufacturing temperature) to be used in roads that support high traffic volumes and/or severe environmental conditions. For this purpose, various studies were conducted both in a laboratory and in a real asphalt plant (at binder and mixture level). Later, these materials were used to construct a trial section in a highway at a mountain pass (at more than 1400 m above sea level) supporting more than 2600 heavy vehicles each day under severe environmental conditions (snow during winter, and high temperatures and many hours of solar radiation during the summer). The results indicate the viability of using these materials, since they provide a number of advantages such as improved workability at lower temperatures and an increase in the mechanical resistance against the main sources of distress that affect asphalt pavements.

Factors Related to the Appearance of Transverse Bumps in Asphalt Overlays Placed over Crack Sealant

2017 ◽  
Vol 2630 (1) ◽  
pp. 128-133
Author(s):  
Scott Shuler
Keyword(s):  
Asphalt Mixture ◽  
Application Rate ◽  
Asphalt Pavements ◽  
Transverse Cracks ◽  
Water Intrusion ◽  
Asphalt Overlay ◽  
Bow Wave ◽  
Tack Coat ◽  
Asphalt Overlays ◽  
Pavement Foundation

Crack sealants often are used as a preservation tool in asphalt pavements. These sealants are placed in cracks to prevent water intrusion into the pavement foundation. Through the reduction of water intrusion, the strength of foundation layers is maintained, and acceptable pavement performance is extended. However, when a hot-mix asphalt overlay is placed on top of a pavement that contains crack sealants, a bump and additional transverse cracks sometimes occur in the new overlay asphalt. These bumps and sometimes transverse cracks are initiated during breakdown rolling and become progressively more severe on further compaction. This paper presents the results of a 5-year study designed to identify factors that related to the appearance of these bumps and consequent cracks. The results of the study indicated that vibratory breakdown rolling, pavement gradient, sealant geometry, tack coat application rate, and tack coat adhesivity were factors that contributed most to the occurrence of bumps and transverse cracks during asphalt overlay construction over crack sealants. Observations suggested that transverse bumps and consequent cracks occurred in proportion to the size of the bow wave of asphalt concrete present immediately in front of the breakdown roller. The increase in the bow-wave size depended on asphalt mixture properties, breakdown roller size, speed, vibration characteristics, and pavement gradient. Three pavement test sections also indicated that the tack coat application rate had an effect on reduction in the appearance of transverse bumps.

IR Thermography Scanning Technique in the Assessment of Airport Pavements

2001 ◽  
Author(s):  
Antonia Moropoulou ◽  
Nicolas P. Avdelidis ◽  
Maria Koui
Keyword(s):  
Research Work ◽  
Asphalt Pavements ◽  
Transportation Engineering ◽  
Ir Thermography ◽  
In Situ Tests ◽  
Engineering Structures ◽  
Materials Engineering ◽  
Flow Through ◽  
Asphalt Overlays ◽  
Non Destructive

Abstract Corrosion of asphalt pavements is a major problem involved with materials engineering and transportation engineering. Asphalt pavements frequently start to deteriorate slowly primarily, gradually progressing to failure. Such failure can be expensive in terms of both money and lives, but can also be prevented. For that reason, intelligent techniques should be suggested, with the intention of examining the condition of such engineering structures. IR thermography is a non-destructive technique that has the ability to inspect effectively substantial areas, such as airport pavements. It has been used successfully in the detection of cracks, voids and other imperfections appearing either from the aging of the materials or due to poor workmanship. Investigation of asphalt overlays by the means of IR thermography is possible, given that subsurface defects in a material influence the heat flow through that material, generating surface temperature alterations. Despite that, other issues such as, environmental conditions and surface temperatures should also be considered, in an attempt to obtain reliable results. In this research work, a selection of asphalt pavements located at the International Airport of Athens, in Greece, are investigated by the use of scanning IR thermography. In conclusion, this paper describes the problem of deteriorated airport pavements, the process and the apparatus used for the in situ tests, whilst the results obtained lead to the suggestion of a predictive monitoring non-destructive technique for the inspection and appropriateness of airport pavements.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

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