Welcome to TRB WORKSHOP 153 SOUTH AFRICAN HIGHWAY TECHNOLOGY AND PRACTICE Marriott Hotel 21 January 2007 1
TRB WORKSHOP 153 SOUTH AFRICAN HIGHWAY TECHNOLOGY AND PRACTICE Moderator Prof. Kim Jenkins SANRAL Chair in Pavement Eng University of Stellenbosch, South Africa 2
Big 5 3
TRB WORKSHOP 153 SOUTH AFRICAN HIGHWAY TECHNOLOGY AND PRACTICE 1 South African Roads Technology in Context Mr Nazir Alli CEO South African National Roads Agency Ltd (SANRAL) #226716 v3 4
EVOLUTION OF ROAD ADMINISTRATIONS NETWORKS, RESEARCH AND DEVELOPMENT Interdependent Political/Economic/Social Systems Various Stages of Research and Development Birth Growth Upgrading Maturity 1830 1935 1935 1955 1955 1976 1976 onwards 5
Development of Mountain passes Bain s team (Andrew Geddes and son Thomas),1800 s Result: - Engineered drainage - Selected gravel layers - Geometry At the time applied research did not exist 6
INSTITUTIONS Academic The South African College, established in 1829 University of Cape Town, first to offer Civil Engineering Courses during the years 1902-1918 Others Roads and Bridges Committee established in January 1925 - Appointed by Minister of Mines and Industries The Cape Society for Civil Engineers established in 1903 - requested research use of tar in 1933 7
South African Roads Board Appointed in 1935 1938 road surfacing specifications evolved The Cement and Concrete Institute was established in 1938 The Council for Scientific and Industrial Research (CSIR) formed in 1945 1949: CSIR requested to research into tar rather than bitumen from imported crude Use of tar products now discontinued Bituminous Binder Research Unit, 1951: CSIR - 1 st road surfacing experiment 8
National Institute for Road Research, 1955: CSIR National Institute for Transport and Road Research, 1975: CSIR Committee of State Road Authorities, late 1970 s Southern African Bitumen and Tar Association established in 1979 - representing industry 9
PAVEMENT ENGINEERING Late 60 s and early 70 s subset of geotechnical engineering Chair in Transportation at the University of Pretoria in mid 80 s - Department of Transport Dedicated Chair, University of Stellenbosch, SANRAL, 2001 Research - properties of materials - behaviour under loads - transfer mechanism 10
SOUTH AFRICAN MECHANISTIC DESIGN METHOD Origin of Current SAMDM Damage Models Fatigue of asphalt concrete wearing courses - Freeme 1970s Fatigue of asphalt concrete base layers including temperature - Published data 1970s to 1980s Permanent deformation for unbound material - Maree 1970s to 1980s
Effective fatigue and crushing failure for cement stabilized layers - de Beer 1980s Vertical strain criteria for subgrade - Dorman and Metcalf 1965 Stress in Motion, measures 3 D contact stresses - de Beer 1995 12
DESIGN OF CONCRETE PAVEMENTS IN SOUTH AFRICA Design approach of the USA was selected as a guide - late 60 s early 70 s Experimental road on S12 Ogies - Mid 1970 s Department of Transport issued standard details for design and construction based on Road Note 29 (UK) - 1977 13
Design Manual M10 launched using nomographs based on mechanistic principles - 1995 Probabilistic computer program cncrisk released - 2001 Updated programme cncpave launched - 2003 cncpave updated based on data from HVS testing - 2005 14
Ultrathin continuously reinforced concrete pavement (UTCRCP) - 2006 cncpave being updated to include UTCRCP - 2007 15
PUBLICATIONS Technical Recommendations for Highways - established in the early 70 s - contains the compilation of research technology in a specific field - compiled by state authorities - used by all institutions as references and handbooks Technical Methods for Highways - established the late 70 s - mandatory documents 16
ACCELERATED PAVEMENT TESTING Heavy Vehicle Simulator Static linear tracking pavement loading device, late 1960 s Various improvements Mobile Load Simulator, 1991 Various improvements 17
OBSERVATIONAL TECHNIQUES Microscope - crack movement on concrete Scanning Electron Microscopy - Bitumen on soil particles - different types of sands Atomic Force Microscopy - Binder surface properties 18
Computerised Tomography - aggregate packing - void distribution - density gradients Infrared Thermography - construction control 19
FUTURE? Integration of two components Information system based on past performance Mechanistic-Empirical analysis and design system Performance based information system Validation data set for reality checks and calibration Starting point for design coupled with MEdesign using default input values for preliminary design and training 20
ME-design component Provides opportunity for design refinement Project specific input combined with design expertise Utilisation of available road-building material Pre-processing Post-processing Traffic loading Axle load and contact stress histograms are timedependent Frequency Frequency Extent of fatigue Frequency ME-design core Time Fatigue life Axle load Contact stress Rut Frequency Terminal rut Spatial variation of field variables Layer thickness Temperature Binder content Relative density Saturation Grading etc. Certain field variables are time-dependent in addition to spatial variability Time Rut life T 1 T 2 T 3 T n RD 1, S 1 RD 2, S 2 RD 3, S 3 RD n, S n Riding quality Frequency σ 1 b, ε1 b σ 2 b, ε2 b σ 3 b, ε3 b σ n b, εn b Unacceptable Time Riding quality life 21
PROCUREMENT Advances in contractual arrangements comparable Technological advances in other sectors 22
OUR AIM WITH TECHNOLOGICAL ADVANCES Vehicle Now User Vehicle Our aim User Common ground created by legal and technology architecture 23
RATIONALE FOR NEW STYLE CONTRACT Where fraud is exposed, complex process required to differentiate between causes: - human responsibility - equipment deficiencies Single point of responsibility Incentivise: - risk sharing - quality - delivery/costs 24
BENEFITS OF ADVANCES IN CONTRACTUAL ARRANGEMENTS Business practices Business processes Organisation structures Take advantage of opportunities offered and reflect needs of workforce Law must reflect expectations of society Benefits Pro-active Efficient Quality driven 25
THANK YOU www.nra.co.za 26