Insights into pavement material density and strength

Abstract

Paper presented at the 25th Annual Southern African Transport Conference 10 - 13 July 2006 "2010: Will transport infrastructure and systems be ready?", CSIR International Convention Centre, Pretoria, South Africa. ABSTRACT: Properties of soils provide far more information than typically used in construction quality control. The aim of this paper is to present mathematical evidence of the relation between soil properties such as porosity, soil interlock and bearing capacity and to demonstrate it's applicability in pavement layer construction control. Basic soil parameters are presented, and their interrelationships, whereafter these parameters are combined in mathematical relationships and their application in quality control demonstrated. The determination and use of the soil parameters; porosity and degree of interlock is suggested as a more pragmatic means of assessment of a state of soil compaction than the more traditional Relative Compaction of a so called maximum laboratory density. Soil groups may be related to porosity at maximum density which can be mathematically calculated from a single "one-shot" density test. Strength in the form of a possible minimum CBR of a soil at different moisture contents and density is shown to be mathematically assessable.