Aspects of Current MLS APT Activities in southern Africa Fred Hugo Road Pavement Forum 7 November 2006

Applications of MLS technology  ITT - Univ of Stellenbosch Evaluation of Proprietary Cold mixes Evaluation of Proprietary Cold mixes Development of new design approach for the ANE in Mozambique [MLS10 and MMLS3] Development of new design approach for the ANE in Mozambique [MLS10 and MMLS3]  SRT laboratory KZN Evaluation of HMA performance on airports and highways Evaluation of HMA performance on airports and highways Local evaluation of design mixes prior to paving (field and lab) Local evaluation of design mixes prior to paving (field and lab)  Roadlab Local evaluation of design mixes prior to paving Local evaluation of design mixes prior to paving Participation in research project of GDPWT in conjunction with the HVS Participation in research project of GDPWT in conjunction with the HVS   See:

Applications of MLS technology  ITT - Univ of Stellenbosch Cold mixes Cold mixes Development of new design approach for the ANE in Mozambique [MLS10 and MMLS3] Development of new design approach for the ANE in Mozambique [MLS10 and MMLS3]  SRT laboratory KZN Evaluation of HMA for application on airports and highways nationally and internationally Evaluation of HMA for application on airports and highways nationally and internationally Evaluation of factors affecting mix performance Evaluation of factors affecting mix performance  Roadlab laboratory Gauteng Evaluation of design and construction of mixes for consultants contractors and authorities Evaluation of design and construction of mixes for consultants contractors and authorities Participation in research project of GPWTD in conjunction with the HVS Participation in research project of GPWTD in conjunction with the HVS   See:

ITT University of Stellenbosch Testing of Cold Mixes  Evaluate performance of five proprietary cold asphalt mixes available in South Africa tested to evaluate rutting performance and tested to evaluate rutting performance and susceptibility to moisture damage susceptibility to moisture damage  Laboratory characterisation supplementary

SRT commercial laboratory Testing of  Binders  Different materials  Different mix types  National roads  Wide range of airports Specimens transferred across countries and continents – SA, Africa, Australia, Dubai Specimens transferred across countries and continents – SA, Africa, Australia, Dubai  Higher temperatures  Varying speeds

Roadlab commercial laboratory Testing of  UTFC to evaluate influence of flakiness  Comparison of lab design mix performance to field mix performance.  Scheduled to do testing in conjunction with the CSIR - HVS to evaluate asphalt surface layers  Factors include among other: Layer thickness Layer thickness Contact stress Contact stress Temperatures Temperatures Varying speeds Varying speeds Aging Aging

Evaluation of Long-Term Behaviour of Pavement Layered Materials by means of APT and Supplementation/Verification Testing in Mozambique With permission of Administraçao Nacional de Estradas (ANE) Contract 206/CON/ES/DEN/2003 The University of Texas & MLS Mozambique JV

Location: Stellenbosch and Mozambique

Pavement Composition

Mozambican Pavement Structure Actual Performance

Project Background  ANE embarked on an APT program as most cost effective means to: Evaluate construction techniques Evaluate construction techniques Determine most economical use of available “sub-standard” materials Determine most economical use of available “sub-standard” materials Develop a mechanistic-empirical design system best suited for its needs with due regard to materials and environment Develop a mechanistic-empirical design system best suited for its needs with due regard to materials and environment

MMLS3 MOBILE MODEL LOAD SIMULATOR

Third Scale Construction in Laboratory

Construction

Laboratory Test Conditioning Hot air used for heating surface to 55 C Recirculated water on surface at 20 C Trafficking alternated between heated load applications and wet load applications Protocol selected to simulate critical field conditions

Distress Development

MLS10 ROAD TESTER FULL SCALE PAVEMENT TESTING

Construction of Full Scale Test Sections

MLS10 in laboratory in Stellenbosch during shake down testing Pre-commission Testing Stellenbosch University March/April 2006

MLS10 VIDEO

MLS10 Characteristics  Max speed 26 k/h  Max no. of load applications per hour 7,200  Wheel load - half axles: 4 ton – 7.5 ton (max) on duals 4 ton – 7.5 ton (max) on duals 5,5 ton on Super single wheels. 5,5 ton on Super single wheels.  Wheel size, tire type/pressure 295/60 R22.5 and 295/60 R22.5 and Super single 385/65. Super single 385/65. Continental 850 kPa pressure – testing up to 1,000 kPa Continental 850 kPa pressure – testing up to 1,000 kPa

MLS10 testing on site: Manhiça Mozambique

Wheel Path on Pavement

Surface Damage: Cracking and Pumping

Rut Accumulation

Distress monitoring via P SPA

Diagnostic Removal of Trafficked CTB Slab

1.5m 400mm 150mm Extracted fractured pavement - confirming manifestation of distress Planview Section

MMLS3 and MLS10 proving to be APT tools for evaluating pavement performance in terms of shear, interlayer distress, rutting, fatigue and susceptibilty to moisture damage, in the laboratory and in the field under different environmental and age conditions

QUESTIONS? QUESTIONS? See: