ROADBASES: ANALYSIS OF IN SITU TESTS ON TEST SECTIONS

This paper describes the results of several tests performed on both the paved and unpaved parts of ten test sections with different roadbase materials at the Road and Railroad Research Laboratory of the Delft University of Technology. The aim of the tests was to assess and model the mechanical-structural performance of roadbase materials. The following tests were performed: a) static and dynamic plate bearing test; b) Clegg hammer; c) falling weight deflection measurement; d) asphalt strain measurement; e) triaxial test with cyclic load; and f) four point bending test. The measurements were conducted for a period of more than one year in order to monitor the development of the roadbase stiffness. The analysis of the results with the linear-elastic multilayer programs BISAR and MISS is summarized. It appeared that with several materials the development of the stiffness still continues, even after a period of three months. The scattering, however, also increases considerably. It was observed that the Clegg hammer results do not correlate well with the roadbase stiffness. On the other hand the dynamic plate bearing test was found successful for a quick assessment of the stiffness of the road structure under construction. For the covering abstract of the conference see IRRD 867688.