Kocouvi Agapi HOUANOU^1,, Constant Euloge ADJAGBONI¹, Kpomagbé Serge DOSSOU¹, Antoine VIANOU¹

This study explores the relationship between thermal conductivity and the California Bearing Ratio (CBR) index of lateritic gravel, an essential road construction material in tropical regions. The main objective is to assess how the thermal properties of this material, sourced from the Cana Atchia quarry in Benin, influence its mechanical performance with a view to optimizing the durability of road infrastructure. The methodology adopted consisted of conducting thermal conductivity and CBR tests on samples of lateritic gravel compacted at different rates: 90%, 95%, 97%, and 100% of the OPM dry density. For each compaction rate, the CBR was measured on test specimens that had undergone a thermal test and on unheated control specimens. This study showed that increasing the compaction rate leads to an increase in thermal conductivity. For each of the target compaction rates, the CBR values of the specimens subjected to thermal testing were consistently lower than those of the unheated specimens, demonstrating that heat has a negative impact on the bearing capacity of a lateritic gravel pavement layer. The test also showed that above 95% compactness, the CBR begins to fall as thermal conductivity increases. This phenomenon sheds light on the degradation of the mechanical properties of lateritic gravels under high temperatures.

Thermal conductivity, California Bearing Ratio (CBR) index, lateritic gravel, mechanical performance, temperatures