Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.
aggregate larger than 19 mm be replaced by crushing the oversize material to less than 19 mm. Depending on the magnitude of the oversize material so treated and the manner of the crushing process the resulting density and CBR values obtained from duplicate tests may vary considerably and misrepresent the actual properties of the soil. The aim of the paper is to investigate the influence of oversize replacement (OR) on the laboratory CBR. The variations in maximum density and CBR that oversize replacement affect for materials with oversize fractions ranging from 20 to 40% are significant. Materials with large fractions greater than19 mm should not be tested for CBR as a strength criterion but should be treated in the manner of crushed stone materials by compacting to a specified solids ratio.
