Sabita Bitumen Durability Project Johan Muller 6 May 2008

Background RSA vs. USA and the rest of the globe SUPERPAVE Sprayed Seals vs. HMA Penetration vs. Performance graded Ageing vs. Durability RTFOT vs. PAV vs. RCAT vs. RTFOT (extended) Lab vs. Field (trials) Validation

Ageing vs. Durability

Who is involved - Internally? Sabita funded Trevor Distin Univ. Stellenbosch Prof Kim Jenkins Tosas (research leader) Johan Muller Tosas (project executor) Tertius Joubert STFR (Jacques van Heerden STFRGerhard Harmse Natrefallows us to utilise facilities CSIREsbe van Assen CSIRBenoit Verhaeghe

RSA vs. USA vs. Europe vs. Australia USAProf Hussain Bahia Univ. Wisconsin EuropeProf Martin van de Ven TU Delft ARRBJohn Oliver / Peter Tredrea AAPAWalter Holcroft / Rob Vos? Who is involved - Externally?

What is involved? RTFOT, RTFOT, RTFOT Natref, Tosas STFR Penetration, R&B, Viscosity Natref PAV STFR RCAT TU DELFT? DSR STFR Bending Beam STFR FTIR Sastech SARA ( HPLC at CSIR or IATROSCAN at Natref )

What is involved? Courtesy of ARRB (John Oliver)

What do we want to achieve? Develop an internationally acceptable durability protocol Relate Laboratory ageing to the actual ageing in the field Ultimately predict the difference in the behaviour of the GOOD, the BAD and the UGLY

How do we want to achieve this Confirm CSIR durability protocol Refine the protocol where necessary

What are the variables? Temperatures / time relationship Higher temperature faster ageing Longer time more ageing The optimum rate of ageing yielding –the same chemistry and – SAME STIFFNESS WHICH RESULTS IN BITUMEN BECOMING TOO BRITTLE

What is involved? BINDERS Modified / Unmodified SEALS HMA Experimentation of ageing Measure ageing effect with time Laboratory Simulation Field Trials CORRELATION VALIDATION IN-SERVICEPLANT