Design of long life pavements based on thin high strength cement bound bases. M7/M8 Portlaoise Motorway experience (Ireland)

A long life pavement could be defined as that capable of withstanding the traffic loadings with no need to carry out a structural strengthening, being exclusively free of surfacing interventions during a 40 years design life period approximately. Based on this philosophy, both foundation and pavement have been designed in one of the major areas that conform the Irish Motorway network, the M7/M8 Portlaoise to Cullahill / Castletown PPP Motorway Scheme sections, which add up to 41 km in length. The long life pavement designed is a flexible composite one that includes the innovations as follows: a) Use of low noise surface course in order to achieve 3 dB(A) traffic noise reduction; b) Use of thin (150 mm thickness) high strength cement bound bases (above 20 MPa) in order to increase the pavement durability, achieve a water infiltration reduction through the upper asphalt layers caused by possible leaks, and reduce the pavement construction costs; c) Pre-cracking on the cement bound granular base at one meter spacing, in order to delay the down-up transversal cracking reflection caused by thermal retraction, throughout the design period; and, d) Design of a high strength foundation, achieving equivalent stiffness modulus above 400 Mpa; this is based on the use of a multi-layered system formed by two cement bound layers that perform as non-deformable leans and provide a lower susceptibility to water infiltration, instead of using the traditional foundation formed by capping and a granular sub-base.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 15p
  • Monograph Title: 24th World Road Congress Proceedings: Roads for a Better Life: Mobility, Sustainability and Development

Subject/Index Terms

Filing Info

  • Accession Number: 01519951
  • Record Type: Publication
  • ISBN: 2840602679
  • Files: TRIS
  • Created Date: Feb 28 2014 5:17PM