revision of tg3 from asphalt reinforcement to subgrade ... · tg3 (2008) – asphalt reinforcement...
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Revision of TG3 - From Asphalt Reinforcement to Subgrade Stabilisation
Colin Gewanlal Arno HeferTensar International Rubicon Solutions
Current TG3
• Only covered Asphalt Reinforcing
• The geosynthetic industry has grown significantly
• Geosynthetics are now accepted globally for:
subgrade stabilisation,
optimisation of the structural pavement layers
asphalt reinforcement
TG3 Revision
• Practical, state-of-the-art approaches
• Best practice, knowledge and experience
• A diverse variety of product types and application areas connected to all components of road pavement layers
• Great care is being taken to maintain a generic focus on products and systems.
Benefits to Society
Society
• Better use of tax-payers money
• Labour-based construction practises can be designed in > Job-creation.
• Improved quality of life and economic opportunities for low-income communities
• Less inconvenience for the road-user.
Benefits for the Planet
Environment
• Can be made from recycled materials > Job-creation.
• Reduced project carbon footprint due to reduced granular thickness
• Marginal fills can be used
• Can be made from natural materials > Job-creation.
Benefits for the TG3 User
Students
• Use as a reference
• Get an introduction to the industry
• Use for study purposes
Benefits for the TG3 User
Practicing Engineers
• Be aware of the state of the art
• Design methods guidance
• Model specifications
• Construction monitoring guidance
Benefits for the TG3 User
Contractors
• Construction guidelines
• Improved workmanship
• Improved production
• Less wastage
Benefits for the TG3 User
Project Owner
• Understanding how to leverage geosynthetic technology to save money
• Incorporating labour based construction practises into his project
Sources of Information
• Collaboration of the TG3 Working Group with national committees responsible for the development of local standards was facilitated
• Some TG3 group members are also members of the SABS committee on geosynthetics (SABS/TC081/SC05), representing the national mirror committee of the ISO technical committee on geosynthetics.
Structure of document
Design with Geosynthetics
Design with Geosynthetics
Design with Geosynthetics
Design with Geosynthetics
• PAVED ROADS: ASPHALT LAYERS
• PAVED ROADS: GRANULAR LAYERS (INCL. SUBGRADE)
• UNPAVED ROADS
• MECHANISMS
• CONCEPTS & PRINCIPLES
• DESIGN METHODS
Design with Geosynthetics
PAVED ROADS: ASPHALT LAYERS
Design with Geosynthetics
PAVED ROADS: ASPHALT LAYERS
Design with Geosynthetics
Design with Geosynthetics
PAVED ROADS: GRANULAR LAYERS – 2D
Design with Geosynthetics
PAVED ROADS: GRANULAR LAYERS – 3D
Design with Geosynthetics
PERFORMANCE IMPROVEMENT FACTORS
OUTPUT - BASED INPUT - BASED
Traffic Benefit Ratio (TBR)
Base Course Reduction Factor
(BCR)
Layer Coefficient Ratio (LCR)
Modulus Improvement Factor (MIF)
• Concepts & principles adopted internationally• ISO TC 221 (on geosynthetics) and Dutch Guidelines• Validation of performance factors with AASHTO R50-09 framework as basis
Design with Geosynthetics
• Include methods well-established in geosynthetics community; such as AASHTO
• Focus on compatibility with local methods; such as SAMDM
Conclusions
TG3
TG3 (2008) – Asphalt Reinforcement for Road
Construction TG3 (Revision) – The use of Geosynthetics
in Pavements
Paved - AsphaltPaved – Granular
Unpaved
SelectionDesign
SpecificationsConstruction & QC
Best practice guideline, in line
with international trends and local
experience
Industry workshops
Draft early 2020