The role of unbound aggregate layers in reflective cracking

Title: The role of unbound aggregate layers in reflective cracking
Author(s): M. Zeghal, El H.H. Mohamed
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: 103 - 113
Total Pages: 11
Nb references: 3
Language: English

Abstract: 
Adding a new asphalt layer remains one of the most common road rehabilitation procedures. However, reflection of cracks in the existing layers onto the new surface continues to reduce the effectiveness of overlays. This phenomenon has been studied for more than twenty years and most of the effort was focused on the asphalt concrete layer. Consequently, the role of unbound aggregate layers in the mechanisms governing the initiation and propagation of reflective cracking received little attention.

This paper presents the results of an analytical investigation aimed at defining the contribution of granular base and subbase layers to the process of crack reflection. The discrete element modeling technique was used to determine if these layers contribute to crack reflection taking into account their discontinuous and heterogeneous nature. The crack in the original asphalt layer, responsible for uneven traffic load transfer to granular base layers, was modeled as a discontinuity in the pavement structure. Uneven load transfer is compounded more by the non-typical response of granular materials. This uneven loading condition results in a non-uniform stress distribution under the asphalt concrete and creates a state of stress that will contribute to the opening, reflection and propagation of cracks onto the asphalt overlay.

Online publication: 2009-12-23
Publication type : full_text
Public price (Euros): 0.00