Page 9 - SAPEM-Chapter-10-2nd-edition-2014

South African Pavement Engineering Manual
Chapter 10: Pavement Design

5. Pavement Investigation and Design Process .................................................................................. 54
5.1 Design Investigation ............................................................................................................. 55
5.1.1 New Design ............................................................................................................... 56
5.1.2 Rehabilitation Design .................................................................................................. 56
5.2 Design Considerations ........................................................................................................... 62
5.2.1 Material Availability and Cost ....................................................................................... 62
5.2.2 Constructability .......................................................................................................... 62
5.2.3 Performance Adequacy ............................................................................................... 62
5.2.4 Maintainability ............................................................................................................ 62
5.3 Structural Pavement Design ................................................................................................... 62
5.3.1 New Design ............................................................................................................... 62
5.3.2 Rehabilitation Design .................................................................................................. 62
5.4 Economic Assessment ........................................................................................................... 66
6. Structural Capacity Estimation ........................................................................................................ 70
6.1 General Comments on Mechanistic-Empirical Design Methods ................................................... 70
7. Structural Capacity Estimation: Flexible Pavements ..................................................................... 74
7.1 South African Mechanistic-Empirical Design Method (SAMDM) ................................................... 74
7.1.1 Hot Mix Asphalt Fatigue .............................................................................................. 75
7.1.2 Unbound Granular Base and Subbase Layer Permanent Deformation ............................... 76
7.1.3 Waterbound Macadam ................................................................................................ 81
7.1.4 Cement Stabilized Base and Subbase Layers ................................................................. 82
7.1.5 Subgrade Permanent Deformation ............................................................................... 85
7.1.6 Analysis Positions for Critical Stress and Strain Parameters ............................................. 86
7.1.7 General Comments on SAMDM 1996 ............................................................................ 86
7.2 Pavement Number (PN) Design Method .................................................................................. 88
7.2.1 Applicability of Pavement Number Method .................................................................... 88
7.2.2 Rules of Thumb / Departure Points .............................................................................. 88
7.2.3 Pavement Number Calculation ..................................................................................... 92
7.2.4 Pavement Capacity Calculation..................................................................................... 92
7.2.5 Comment on the PN Method ........................................................................................ 92
7.3 Dynamic Cone Penetrometer (DCP) Method ............................................................................ 94
7.4 The AASHTO Structural Number (SN) Method .......................................................................... 97
7.5 Deflection Bowl Parameter Analysis ........................................................................................ 99
7.6 Falling Weight Deflectometer (FWD) SN design method.......................................................... 101
7.7 The TRRL Surface Deflection Design Method ......................................................................... 102
7.8 The Asphalt Institute Surface Deflection Design Method ......................................................... 105
7.9 Summary of Suitability of Structural Design Methods for Flexible Pavements ............................ 107
7.9.1 Comment on Determining Remaining Life ................................................................... 107
7.10 Software Packages for Flexible Pavement Design ................................................................... 107
7.10.1 CYRANO .................................................................................................................. 107
7.10.2 PADS Software Series ............................................................................................... 108
7.10.3 Rubicon Toolbox ....................................................................................................... 110

8. Structural Capacity Estimation: Concrete Pavements ................................................................. 112
8.1 Manual M10 ....................................................................................................................... 112
8.2 Mechanistic-Empirical Design Method for Concrete Pavements ................................................ 115
8.3 Summary of Suitability of Structural Design Methods for Concrete Pavements .......................... 118
8.4 Software Package for Concrete Pavements: cncPAVE ............................................................ 118
9. Structural Capacity Estimation: Concrete Block Pavements........................................................ 120
9.1 Equivalent Thickness Concept .............................................................................................. 120
9.2 Catalogue Design Method .................................................................................................... 120
9.3 Research Based Design Methods .......................................................................................... 121
9.4 Mechanistic Design Methods for Block Pavements .................................................................. 122
9.5 General Aspects for Design of Block Paving ........................................................................... 123
9.6 Software Packages for Concrete Block Pavement Design ........................................................ 123
9.6.1 Lockpave ................................................................................................................. 123
9.6.2 blokPAVE ................................................................................................................. 124
References and Bibliography ................................................................................................................... 125

Preliminary Sections
Page vi