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CSIR-UCB research programme. Road Pavements Forum 14 November 2001. Where did it start?. Officially started in 1994 Sale of two refurbished HVS Mk IIIs Technology transfer package in addition to sale of HVSs Initial stages: HVS operation Later stages: Value addition projects.
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CSIR-UCB research programme Road Pavements Forum 14 November 2001
Where did it start? • Officially started in 1994 • Sale of two refurbished HVS Mk IIIs • Technology transfer package in addition to sale of HVSs • Initial stages: HVS operation • 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 Post-graduate training Contractor: Dynatest Inc Dr N Coetzee Subcontractor: Transportek, CSIR HVS and other value addition projects
Post graduate studies • Masters degrees • Louw du Plessis • Leoni Louw • Jeremy Lea • Ph Ds • Fenella Long • Non-linear visco-elastic modelling of asphalt • Jorge Prozzi • Empirical models of pavement deterioration developed from multiple data sources (near completion) • Andrew Heath • A constitutive model for unbound materials (in process)
HVS operation • Field operations • Rigid pavement testing • Rapid setting concrete • Dowel- and tie-bars • Widened slabs • Dowel-bar retrofit
HVS operation • Field operations • Palmdale – Operator and assistant operators
Value addition projects • Rigid pavements • 1st level analysis of HVS data • Flexible pavements • Mechanistic-empirical design • Subgrade design • Unbound materials • Pozzolanic stabilization • Deep in situ recycling
Value addition projects:Rigid pavements • 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” • Longitudinal cracking of slabs because of cantilever effects • Preliminary conclusions • Reduce stiffness of support layer • Narrow slabs with tie-bars better than • widened slabs without tie-bars and • narrow slabs without tie-bars
Value addition projects:Flexible pavements • Mechanistic-empirical design • Input at bi-annual workshops • Probabilistic design (risk of failure) • Material response characterization • Elastic response – Resilient modulus models • Plastic response – Permanent deformation transfer functions • Utilization of PMS data for validation of M-E design method
Value addition projects:Flexible pavements • Subgrade design • Analysis of all suitable HVS data from Richmond Field Station and South Africa • New insight into subgrade behaviour • New subgrade design critical parameters and transfer functions
Subgrade design:Plastic response R2 = 0,659 SEE = 0,375
Value addition projects:Flexible pavements • Unbound materials • Comparison with Californian aggregate • Material specification • Construction quality (density specification) • Synthesis report on South African experience • Advanced laboratory testing and material modelling • HVS test results • Pozzolanic stabilization • Synthesis report on South African practice • Material and quality specification • Mechanical behaviour • Durability study (carbonation) of cement-treated material and lean concrete
Value addition projects:Flexible pavements • Deep in situ recycling • Synthesis report on selected South African experience • Process promoted by AALP in CALTRANS regions • Lots of interest from regions and CALTRANS Research • Gautrans comprehensive RDI plan • 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
Conclusions • International Technology Transfer in action • Financial benefit not only to CSIR but South Africa • South African practical expertise exchanged for top international analytical skills