Terence Milne

1
South AfricanRoad Pavement Forum13 14
November 2002
Conference Report Back ICAP 2002 17 22 AUGUST
2002 COPENHAGEN

• Terence Milne

2
ATTENDANCE

• Over 40 countries represented by nearly 400
  delegates

• 34 Delegates from South Africa

3
SCOPE OF CONFERENCE

• Parallel Sessions

• Design

• Construction and Maintenance

• Performance

• Environment

• Accelerated testing

• Plenum Sessions

• www.asphalt.org

4
PRESENTATION

• Examples of World Wide presentations

• 120 papers presented

5
PLENUMS

• Perpetual Pavements

• Endurance of 50 years

• Asphalt Pavement Alliance (USA) Guidelines for
  Design and Construction

• UK Long life pavements

• Europe

• 10 Road Laboratories Project

6
PLENUMS (cont.)

• Keynote Addresses

• e.g. Prof Per Ullidtz

• Analytical tools for design of flexible pavements

• - Analytical empirical method of pavement design

• Differences between the assumptions for
  analytical models vs the reality of pavement
  materials and behaviour

• Linear electric theory vs back calculated layer
  moduli

7
PLENUMS (cont.)

• Keynote Addresses

• Analytical tools for design of flexible pavements

• Discrete element modeling deals with the forces
  on, and displacements of individual grains in a
  particulate medium

8
DESIGN

• Binder Rheology

• Belgium

• Looking at reliable standard testing method

• Bending Beam Rheometer or Dynamic Rheometer

• Long term ageing

• Design Parameters

• USA

• Uncertainty and appropriate use of CBR design of
  air fields

• Japan

• Structural design of airport asphalt pavements on
  soil with high water table

9
DESIGN (cont.)

• Material Models

• UK

• Constitutive material modeling for asphalt mixes

• Elastic visco plastic model with input required
  from uniaxial test data (3 temperature and 3
  displacement rates)

• Netherlands

• Design aspects for wearing courses on orthotropic
  steel bridge decks

• Development of a FEM based model going beyond
  linear elastic theory

• FEM modeling of elasticity, plasticity, cracking

10
DESIGN (cont.)

• Materials Models

• Netherlands

• Tools developed for the better understanding of
  the interaction between the different components
  of the structure

• South Africa

• Permanent deformation of asphalt concrete
  pavement development of a non-linear visco
  elastic model for mix design analysis

• FE simulations compared to real pavement data

• Non-linear visco elastic constitutive model to
  describe the rutting behaviour of asphalt

11
PERFORMANCE

• Europe

• The design and performance of thin surfacing
  layers

• Role of the binder considered

• Possible failure criteria considered

12
CONSTRUCTION AND MAINTENANCE

• South Africa

• Towards a Performance Related Seal Design Method

• Japan and USA

• Compaction of HMA using a high frequency, double
  drum vibrating roller

• Relationship between roller speed, vibrating
  frequency, number of roller impacts per metre and
  its effect on density obtained on a HMA pavement
  layer

13
IMPRESSIONS

• Materials modeling based on fundamental materials
  characteristics using both Theoretical and
  Empirical relationships (reality always differs
  from a model with its assumptions)

14
IMPRESSIONS

• Papers content ranged from highly involved
  simulations to practical papers such as roller
  compaction

• Cost of technology

• Europe and USA not always agreeing on the way
  forward

• South Africa to take the best from both groups

• Risk assessment in design using probabilities and
  modeling

15
IDEAS FOR CAPSA

• Good mix of plenaries and specialist parallel
  sessions

• Include all events in conference price to keep
  affordable, and delegates involved

• Good idea of display in lunch and tea area

• CAPSA compares well, personal touch too