Mode of loading in reflective and flexural fatigue cracking - A numeric evaluation

Title: Mode of loading in reflective and flexural fatigue cracking - A numeric evaluation
Author(s): J.B. Sousa, J.C. Pais, R.N. Stubstad
Paper category : conference
Book title: Fourth International RILEM Conference on Reflective Cracking in Pavements - Research in Practice
Editor(s): A. O. Abd El Halim, D. A. Taylor
and El H. H. Mohamed
Print-ISBN: 2-912143-14-4
e-ISBN: 2351580265
Publisher: RILEM Publications SARL
Publication year: 2000
Pages: 23 - 35
Total Pages: 13
Nb references: 7
Language: English

Abstract: 
Consulpav International is working closely with the University of Minho in Portugal under a contract from the Rubber Pavements Association to develop a mechanistic procedure for overlay design that directly takes into account the mechanism of reflective cracking as well as classical flexural fatigue cracking. The problem of properly modeling the mechanism of reflective cracking is particularly prevalent in thin asphalt concrete overlays.
To correctly model and predict asphalt fatigue mechanisms in overlays (both flexural and reflective cracking), it is necessary to utilize the correct mode of loading in laboratory tests. The mode of loading chosen should, as closely as possible, reflect the mode of loading which causes crack propagation in the field.
For each of the possible distress mechanisms that cause cracking in pavements, such as thin or thick existing pavement sections, and thin or thick overlays, fatigue characterization using any model must recognize that controlled stress, strain or "work" (stress x strain) will induce significantly different fatigue lives in laboratory tests. As layer moduli are reduced by fatigue mechanisms, it is necessary to investigate which of these parameters (stress, strain or work) remains mostly constant in a field situation so that it can be used as an input control parameter in laboratory fatigue tests.
This paper presents a numerical evaluation, through a finite element simulation, of mode of loading for several types of flexible pavements and overlays placed on these pavements. Stress (load), strain (displacement) and work (load x displacement) control modes are investigated.

Online publication: 2009-12-23
Publication type : full_text
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