Evaluation of performance of asphalt paving mixes under harsh conditions using the MMLS3

The Draft Test Protocol: DPG1: Method for evaluation of permanent deformation and susceptibility to moisture damage of bituminous road paving mixtures using the Model Mobile Load Simulator (MMLS) has load frequency as a test variable. This was added to the original test protocol adopted by the MMLS users group in Baton Rouge in 2004 to simulate harsh trafficking conditions. Indications are that the adaptation was necessary and successful in curbing premature failures. The paper reports on analysis and synthesis of national and international case studies of applications of this mode. Three are in South Africa: One in Western Cape (N1 - Hex River Pass), the other in KwaZulu Natal (N3 - Marianhill) and the third is from an APT HMA field study for Gauteng Government Department of Public Works and Transportation (a test section on the R80). The fourth case study pertains to airport pavements in Dubai and Australia. A synthesis of the case studies provided evidence of the relationship between slow speed MMLS tests and field performance of HMA under harsh full-scale trafficking, thus ratifying the guidelines in DPG1.