Application of Aasho Road Test Results to Design of Flexible Pavements in Minnesota: Fid-Bau Portal

Application of Aasho Road Test Results to Design of Flexible Pavements in Minnesota

E. L. Skok / P. J. Diethelm

The paper is based on selected aspects of a continuing HPR study having the same title. The purpose of the study is to obtain data on existing pavements that will lead to the adaptation of AASHO Road Test concepts and equations for use in Minnesota. In 1963 and 1964 50 representative projects located throughout the state were selected for preliminary investigation. A 1200-foot long by one-lane wide test section was selected in each project for intensive study. The construction history of each project was studied and field inspections were made to obtain general information on the pavement design and condition, roadbed materials, drainage and topography. In the 1200-foot test sections, borings were made to check the uniformity of pavement structure thicknesses and roadbed materials. Initial PSI values were established either by estimation or by roughometer measurements obtained at the time of construction. Periodic roughometer measurements are being made to obtain PSI values for determining performance trends. Periodic plate bearing and Benkelman beam tests are being made to determine the strengths of the various pavement system components. Classification tests of all materials were made. Stabilometer and CBR tests were run on all roadbed materials and on some base and subbase materials. Asphalt was extracted and recovered from the asphalt concrete, and penetration, softening point and ductility tests were made on the recovered asphalt. Flexural beam, modified tension and repeated load tests are being made on the asphalt concrete. Traffic volume, classification and weight data were compiled and a procedure for determining traffic loadings in terms of equivalent daily 18-kip single-axle loads for each test section was developed.