3rd REVISION OF TRH12

1
3rd REVISION OF TRH12

• Renaldo Lorio
• 12th Meeting of RPF - 8 November 2006

2
History of TRH12

• Road rehabilitation research work started circa
  1980
• TRH12 appear in 1983
• 1st revision in 1990/1
• 2nd revision 1997 (minor alterations)
• 3rd revision 2005/6

3
Third revision

• Need identified during 2003
• Obtained comments from individuals
• Workshops
• SANRAL committed funds
• Established committee in 2005

4
Committee

• Renaldo Lorio SANRAL
• Kobus van der Walt SANRAL
• Gerrit Jordaan Tshepega
• Ian van Wijk Africon
• Philip Joubert SSI
• Fritz Jooste MA
• Kim Jenkins US
• Johan Hattingh PHI
• Bryan Perrie CCI
• Andre Molenaar TU Delft - Moderator

5
Overview of comments

• Generally acceptable procedure
• TRH12 more a textbook than a guideline document
• Clear guidelines and procedures required
• Accuracy / correctness of criteria related to
  deflection measurements (different devices)
• Relevance of AI, TRRL and Shell overlay design
• Changes in traffic loading predictions

6
Overview of comments

• Design reliability concept and how to cater for
  variability
• Improve readability and provide examples

7
Objectives

• Define process more clearly
• Provide more definitive guidelines with
  explanatory appendices
• Repackage to make clearer include relevant
  available information
• Improve on some definitions
• Add examples
• Tendering for consultant services

8
Revision process

• Three step approach
• Based on comments received prepare first draft
• Review first draft
• Based on review prepare second draft
• Review second draft
• Prepare third draft
• Final review and finalization

9
Project phases
1997
Detail design
Present Detailed Assessment
Initial assessment
TRH12
Fact finding / diagnosis
Decision making
Finalisation
2006
IAR
DAR
PDR
DR
IR
TD
Investigation and Analysis Evaluation
Rehabilitation Design
10
Most significant changes to date

• Do away with remaining life / end of life
  concepts - replacement not clear as yet but
  will be related to the functionality of the
  pavement
• Relook at the design reliability concepts needs
  revision but not sure what the answer is as yet

11
Most significant changes to date

• Provide definitions for short, medium and long
  term
• Do away with deflection criteria as in Appendix 1
  of 1997 version - misuse
• Rather focus on relative differences
• Include well know Cusum plots

12
Most significant changes to date

• Provide guidelines for the provision of a
  detailed test plan
• What information is needed ?
• How is it to be obtained take account of
  variability
• How is it to be used ?
• Provide guidelines to collate information to be
  exported to other design methods most notably
  SAMDM

13
Most significant changes to date

• Inclusion of concrete (rigid pavement) solutions
  where appropriate
• Possibility of reviving SABITAS REACT software
  to be used in economic appraisal of various
  remedial options
• Literature referred to in the text will be
  provided on a CD as far as copy right
  restrictions provide

14

• Thank you