Simplified Characterization Techniques for (SUB) Tropical Base Materials and Modelling

Simplified Characterization Techniques for (SUB) Tropical Base Materials and Modelling

A. A. Araya

Ethiopian Roads Authority, Addis Ababa, Ethiopia

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Most pavements in developing countries are designed based on index material properties related to a single design chart, restricting the incorporation of marginal and new materials for which the index property data sets are not available. To promote the introduction of naturally abundantly occurring marginal materials as well as recycled road base subbase materials in the road construction in those countries, mechanical behaviour of granular material can be used for design. The mechanical properties of these materials can be obtained from a simplified repeated load California bearing ratio (RL-CBR) characterization technique. An extensive RL-CBR characterization has been carried out on (sub) tropical base and subbase granular materials. A finite element method analysis has been attempted for the purpose of modelling the RL-CBR and derives an equivalent resilient modulus of the sample material. Furthermore, a cyclic triaxial test was carried out to validate the result of the RL-CBR. Through the RL-CBR characterization technique not only the practical accessibility of characterizing the mechanical behaviour of unbound granular materials is enhanced but also the effect of moisture content and degree of compaction on these behaviours is well demonstrated.


granular road base, mechanical behaviour, modelling, repeated load CBR, triaxial test


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