Lecturer, University of the West Indies, St. Augustine,
Pages: 22 Published: Jan 1989
Integration of the asphalt concrete mix design procedure can be achieved through interaction between pavement distress identification, desired mix design parameters and selection of criteria, and territorial constraints including economic, technological, physical, and human resources capabilities. Surveys and investigations in Trinidad and Tobago have identified the critical types of distress as rutting and fatigue cracking, the occurrence of which are dependent on subgrade type and high pavement temperatures. A review and selection of related proven criteria from developed countries has been done to account for them. Structural analysis of full depth asphalt pavement sections has been used to generate strain-stiffness profiles for both types of distress and these profiles were combined with the selected criteria to establish a target mix stiffness. Through trial testing with a selected binder, and use of the Shell Nomograph analysis, it is shown that the target mix stiffness can be converted into stability criteria that can be substituted into Asphalt Institute criteria to provide a complete set of mix design specifications. The procedure has worked well over the past nine months.
mix design, constraints, rutting, fatigue (materials), subgrade type, strain, stiffness, thickness, binder, stability, criteria, asphalt concrete, asphalt specifications
Paper ID: STP20072S