Considering Material Heterogeneity in Crack Modeling of Asphaltic Mixtures

2003 ◽  
Vol 1832 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Jorge Barbosa Soares ◽  
Felipe Araújo Colares de Freitas ◽  
David H. Allen
Keyword(s):  
Fracture Mechanics ◽  
Numerical Method ◽  
Laboratory Tests ◽  
Global Analysis ◽  
Asphalt Mixture ◽  
Local Scale ◽  
Monotonic Loading ◽  
Crack Evolution ◽  
Material Heterogeneity

Cracking in the asphaltic layer of pavement has been shown to be a major source of distress in roadways. Previous studies in asphaltic mixture cracking have typically not considered the material heterogeneity. A numerical method of analysis is presented that is based on the theory of fracture mechanics, in which the binder and the aggregates are treated as distinct materials. The simulations performed are verified and calibrated from simple and conventional laboratory tests. The study investigates crack evolution under monotonic loading, even though the method outlined can be further developed for the investigation of asphalt mixture fatigue. The approach discussed is part of a multiscale framework for pavement analysis, in which the damage due to cracking at the local scale can be considered in a global analysis at the actual pavement scale.

Numerical Method of Discontinuous Displacements in Spatial Problems of Fracture Mechanics

2021 ◽  
Vol 56 (1) ◽  
pp. 119-130
Author(s):  
A. V. Zvyagin ◽  
A. A. Luzhin ◽  
D. I. Panfilov ◽  
A. A. Shamina
Keyword(s):  
Fracture Mechanics ◽  
Numerical Method ◽  
Spatial Problems

On the Multiscale Finite Element Analysis for Interfacial Fracture in Cu/Low-K Interconnects

2007 ◽  
Author(s):  
Tz-Cheng Chiu ◽  
Huang-Chun Lin
Keyword(s):  
Thin Film ◽  
Fracture Mechanics ◽  
Interface Crack ◽  
Integrated Circuit ◽  
Flip Chip ◽  
Thermal Loading ◽  
Global Analysis ◽  
Crack Problem ◽  
Element Analysis ◽  
Low K

The interface crack problem in integrated circuit devices was considered by using global and local modeling approach. In the global analysis the thin film interconnect was modeled by a homogenized layer with material constants obtained from representative volume element (RVE) analysis. Local analyses were then considered to determine fracture mechanics parameters. It was shown that the multiscale model with RVE approach gives accurate fracture mechanics parameters for an interface crack under either thermal or mechanical loads; while significant error was observed when the thin film layers are ignored in the global analysis. The problem of an interface crack between low-k dielectric and etch-stop thin film in a flip-chip package under thermal loading was also investigated as an application example of the multiscale modeling.

Fracture mechanics in design and service: ‘living with defects’ - Concluding remarks

1981 ◽  
Vol 299 (1446) ◽  
pp. 237-239
Keyword(s):  
Fracture Toughness ◽  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Static Loading ◽  
Laboratory Tests ◽  
Stress System ◽  
Unstable Fracture ◽  
Reliable Tool ◽  
System A ◽  
Original Objective

The original objective of this meeting was to assess how fracture mechanics is now being used in practice, both in design and service, in different industries, and the extent to which it is now established as a reliable tool. It was hoped to bring together engineers and scientists with experience in different applications of fracture mechanics. My own impressions of some of the important conclusions that have emerged from this meeting are as follows. 1. The simple concept of a constant fracture toughness controlling unstable fracture under nearly l.e.f.m. and quasi-static loading conditions seems to work remarkably well for a variety of materials, including alloys, plastics and composites (see Professor Williams’s paper). But when plastic deformation becomes significant, there are complications, in particular the effects of triaxiality of the stress system, a point stressed by Professor Burdekin, and also of high rates of strain, which must be taken into account in applying toughness values obtained from laboratory tests to actual structures in service.

scholarly journals Effect of percent air voids content on the deformation properties of the asphalt mixture

2021 ◽  
Vol 1209 (1) ◽  
pp. 012078
Author(s):  
J Bokomlasko ◽  
J Mandula
Keyword(s):  
Laboratory Tests ◽  
Asphalt Mixture ◽  
Road Construction ◽  
Air Voids ◽  
Aggregate Fraction ◽  
Deformation Properties ◽  
Load Effects ◽  
Air Void

Abstract Asphalt mixture is a building material with many advantages. Therefore, it is most used in road construction. If the asphalt mixture is laid with the prescribed technology, it can withstand load effects to long-term. It is necessary to take samples that will be subjected to laboratory measurements. There are several laboratory test, for example measurement thickness of the asphalt mixture layers, the aggregate fraction, quantity of binder in the mixture, determination of air void in asphalt mixture layers. Samples taken directly from the construction site are subjected to laboratory tests. This article focuses on one of the laboratory tests and it is determination of air void in asphalt mixture layers. The determination of air void in asphalt mixture layers is test in detail, because this effect has influence on the deformation properties of asphalt mixture layers. Therefore, it was necessary to model of air void in asphalt mixture layers with different degrees air void. On this purpose was use program Abaqus. The results were plotted. This graphs showed that increasing the air void in asphalt mixture layers has effect on the expansion of deformations. This can lead to faster pavement degradation.

Laboratory Investigation of Asphalt Pavements with Low Density and Recommendations to Prevent Density Deficiency

2013 ◽  
Vol 723 ◽  
pp. 128-135
Author(s):  
Alireza Zeinali ◽  
Phillip B. Blankenship ◽  
R. Michael Anderson ◽  
Kamyar C. Mahboub
Keyword(s):  
Laboratory Testing ◽  
Construction Projects ◽  
Laboratory Tests ◽  
Asphalt Mixture ◽  
The United States ◽  
Binder Content ◽  
Asphalt Pavements ◽  
Construction Sites ◽  
Superpave Gyratory Compactor ◽  
Field Compaction

In most USA asphalt construction projects the goal of compacting a hot-mix asphalt (HMA) layer is to achieve the optimum density which is 92% of the maximum specific gravity (Gmm) of the asphalt mixture. However, this level of density is not always achieved. This paper evaluates the effect of field compaction deficiencies on the HMA durability through laboratory testing. HMA samples were collected from construction sites in the United States. A series of laboratory tests were conducted to compare the performance of HMA mixtures at their actual in-place density as well as the desired density of 92% of Gmm. The statistical analysis on the results showed that the performance of the pavements could significantly improve by eliminating the deficiencies in their in-place densities. Moreover, the compactibility of the mixtures was investigated using the compaction data from the Superpave gyratory compactor. Compaction characteristics of the mixtures were compared to a control mixture, and the results showed that the shortage in the binder content of the mixtures could be a major factor which may have caused the density deficiencies. Furthermore, the effect of higher-than-optimum binder content was evaluated on the compactibility of the control mixture.

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