terence milne south african road pavement forum 13 & 14 november 2002 conference report back:...
TRANSCRIPT
Terence Milne
South AfricanRoad Pavement Forum
13 & 14 November 2002
South AfricanRoad Pavement Forum
13 & 14 November 2002
Conference Report Back:
ICAP 2002
17 – 22 AUGUST 2002
COPENHAGEN
AFRICON
ATTENDANCE
Over 40 countries represented by nearly 400 delegates
34 Delegates from South Africa
SCOPE OF CONFERENCE
Parallel Sessions Design
Construction and Maintenance
Performance
Environment
Accelerated testing
Plenum Sessions
www.asphalt.org
PRESENTATION
Examples of World Wide presentations
120 papers presented
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
PLENUMS (cont.)
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
Keynote Addresses
Linear electric theory vs back calculated layer moduli
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
DESIGN
Binder Rheology Belgium:
Looking at reliable standard testing method
Bending Beam Rheometer or Dynamic Rheometer
Long term ageing
USA Uncertainty and appropriate use of CBR design of air fields
Japan Structural design of airport asphalt pavements on soil with
high water table
Design Parameters
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
DESIGN (cont.)
Materials Models
Netherlands Tools developed for the better understanding of the interaction
between the different components of the structure
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
South Africa
Non-linear visco elastic constitutive model to describe the rutting behaviour of asphalt
PERFORMANCE
The design and performance of thin surfacing layers
Europe:
Role of the binder considered
Possible failure criteria considered
CONSTRUCTION AND MAINTENANCE
Towards a Performance Related Seal Design Method
South Africa:
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
IMPRESSIONS Materials modeling based on fundamental materials
characteristics using both Theoretical and Empirical relationships (reality always differs from a model with its assumptions)
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
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