ASSESSING THE QUALITY OF GRAVEL SUB-BASE. UNBOUND AGGREGATES IN ROADS. PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM, UNIVERSITY OF NOTTINGHAM, APRIL 11-13, 1989

This paper describes research on the development of a rapid test to assess the suitability of granular materials for use in sub-base construction. Such a test would provide an alternative to the full-scale trafficking trials. The method used a modified 300 mm square shear box technique. The results obtained using this technique were compared with the results of full scale trafficking trials on various crushed rocks and gravels. The surface deformation caused by the traffic was found to correlate with the shear strength of the materials measured in a 300 mm square shear-box. It was found that many gravel sub-bases can perform as well as crushed-rock Type 1 sub-bases and that the shear-box test could be used to distinguish between the least and most suitable materials. However, the suitability of material with intermediate shear strength can only be assessed by carrying out trafficking trials. For the covering abstract of the conference see IRRD 827698.