| Summary: | The aim of this research has been to characterise the behaviour of a variety of locally available naturally occurring and artificially prepared aggregates in a form suitable for use in pavement analysis. The materials chosen are commonly used in developing countries as capping layers, subbases and road bases with a maximum size of 38 mm. A review of previous work is presented and details of some improved, simple and practical new experimental techniques developed for both static and dynamic testing of materials are included. The maximum proportion of volume occupied by solids (MPVS) for a granular mixture when compacted to refusal in a dry state was taken as a measure of laboratory compactability. Also the water required to saturate at this MPVS has been found to correspond with the optimum moisture content (OMC). Significant correlations were obtained between MPVS values against coefficient of uniformity on logarithmic scale, MPVS values against fines content (fraction passing 0.075 mm sieve) and MPVS values against angularity number. These correlations indicate that MPVS values obtained in the dry state provide a reliable measure of the combined effects of particle shape, texture, grading and degradation upon compactability. Laboratory testing of materials has been carried out according to the following modes of test: California Bearing Ratio (CBR), Modified Bearing Ratio (MBR), large direct shear box, simple impact hammer test (as developed in Australia) and in both dynamic bearing and triaxial apparatus capable of applying repeated stress in the axial directions. To simulate actual pavement conditions more closely, tests were carried out both on wet and dry mixes using three different gradings namely a normal Fuller grading, a coarser 'lower limit of DT ' grading and a finer Lees' grading.
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