CSIR-UCB research programme Road Pavements Forum 14 November 2001

Where did it start? Officially started in 1994 Officially started in 1994 Sale of two refurbished HVS Mk IIIs Sale of two refurbished HVS Mk IIIs Technology transfer package in addition to sale of HVSs Technology transfer package in addition to sale of HVSs Initial stages: HVS operation Initial stages: HVS operation Later stages: Value addition projects Later stages: Value addition projects

Organisational structure CALTRANS Tom Hoover PRC of ITS PI: Dr J Harvey University of California, Berkeley Contractor: Dynatest Inc Dr N Coetzee Subcontractor: Transportek, CSIR

Technology transfer CALTRANS Tom Hoover PRC of ITS PI: Dr J Harvey University of California, Berkeley Contractor: Dynatest Inc Dr N Coetzee Subcontractor: Transportek, CSIR Post-graduate training HVS and other value addition projects

Post graduate studies Masters degrees Masters degrees Louw du Plessis Louw du Plessis Leoni Louw Leoni Louw Jeremy Lea Jeremy Lea Ph Ds Ph Ds Fenella Long Fenella Long Non-linear visco-elastic modelling of asphalt Non-linear visco-elastic modelling of asphalt Jorge Prozzi Jorge Prozzi Empirical models of pavement deterioration developed from multiple data sources (near completion) Empirical models of pavement deterioration developed from multiple data sources (near completion) Andrew Heath Andrew Heath A constitutive model for unbound materials (in process) A constitutive model for unbound materials (in process)

HVS operation Field operations Field operations Rigid pavement testing Rigid pavement testing Rapid setting concrete Rapid setting concrete Dowel- and tie-bars Dowel- and tie-bars Widened slabs Widened slabs Dowel-bar retrofit Dowel-bar retrofit

HVS operation Field operations Field operations Palmdale – Operator and assistant operators Palmdale – Operator and assistant operators

Value addition projects Rigid pavements Rigid pavements 1 st level analysis of HVS data 1 st level analysis of HVS data Flexible pavements Flexible pavements Mechanistic-empirical design Mechanistic-empirical design Subgrade design Subgrade design Unbound materials Unbound materials Pozzolanic stabilization Pozzolanic stabilization Deep in situ recycling Deep in situ recycling

Value addition projects: Rigid pavements Warping of slabs Warping of slabs In John Harvey’s words: “Tell me the deflection you want and I’ll tell you the time to go and measure” In John Harvey’s words: “Tell me the deflection you want and I’ll tell you the time to go and measure” Longitudinal cracking of slabs because of cantilever effects Longitudinal cracking of slabs because of cantilever effects Preliminary conclusions Preliminary conclusions Reduce stiffness of support layer Reduce stiffness of support layer Narrow slabs with tie-bars better than Narrow slabs with tie-bars better than widened slabs without tie-bars and widened slabs without tie-bars and narrow slabs without tie-bars narrow slabs without tie-bars

Value addition projects: Flexible pavements Mechanistic-empirical design Mechanistic-empirical design Input at bi-annual workshops Input at bi-annual workshops Probabilistic design (risk of failure) Probabilistic design (risk of failure) Material response characterization Material response characterization Elastic response – Resilient modulus models Elastic response – Resilient modulus models Plastic response – Permanent deformation transfer functions Plastic response – Permanent deformation transfer functions Utilization of PMS data for validation of M-E design method Utilization of PMS data for validation of M-E design method

Value addition projects: Flexible pavements Subgrade design Subgrade design Analysis of all suitable HVS data from Richmond Field Station and South Africa Analysis of all suitable HVS data from Richmond Field Station and South Africa New insight into subgrade behaviour New insight into subgrade behaviour New subgrade design critical parameters and transfer functions New subgrade design critical parameters and transfer functions

Subgrade design: Elastic response

Subgrade design: Plastic response R 2 = 0,659 SEE = 0,375

Value addition projects: Flexible pavements Unbound materials Unbound materials Comparison with Californian aggregate Comparison with Californian aggregate Material specification Material specification Construction quality (density specification) Construction quality (density specification) Synthesis report on South African experience Synthesis report on South African experience Advanced laboratory testing and material modelling Advanced laboratory testing and material modelling HVS test results HVS test results Pozzolanic stabilization Pozzolanic stabilization Synthesis report on South African practice Synthesis report on South African practice Material and quality specification Material and quality specification Mechanical behaviour Mechanical behaviour Durability study (carbonation) of cement-treated material and lean concrete Durability study (carbonation) of cement-treated material and lean concrete

Value addition projects: Flexible pavements Deep in situ recycling Deep in situ recycling Synthesis report on selected South African experience Synthesis report on selected South African experience Process promoted by AALP in CALTRANS regions Process promoted by AALP in CALTRANS regions Lots of interest from regions and CALTRANS Research Lots of interest from regions and CALTRANS Research Gautrans comprehensive RDI plan Gautrans comprehensive RDI plan Meeting between E Sadzik, T Hoover, J Harvey and N Coetzee following PMS conference in Seattle Meeting between E Sadzik, T Hoover, J Harvey and N Coetzee following PMS conference in Seattle Pledged support for Gautrans process by funding HVS and laboratory testing Pledged support for Gautrans process by funding HVS and laboratory testing

Conclusions International Technology Transfer in action International Technology Transfer in action Financial benefit not only to CSIR but South Africa Financial benefit not only to CSIR but South Africa South African practical expertise exchanged for top international analytical skills South African practical expertise exchanged for top international analytical skills