Structure evaluation of a tropical residual soil under wide range of compaction conditions

Soil compaction is one of the most common techniques used to engineer the soil. It is especially appealing to developing countries for its cost-effective and sustainable attributes for improving the soil's geotechnical characteristics. The compaction process along with the complexity of residual soils, abundant in the tropics zone, can have an impact on the performance of geotechnical structures built with these soils. Therefore, it is important to understand the influence that certain compaction conditions have on the structure of these materials. To investigate that, mercury intrusion porosimetry tests were performed on compacted samples of a tropical residual soil from Brazil under different conditions of water content and compactive effort. Results show that the compacted soil under all studied conditions presents a bimodal pore-size distribution (PSD). It appears that the low availability of water within the macro-pores, hence suction, could have played a decisive role in maintaining the bimodal framework of the PSD. In this respect, this study contributes to a better understanding of the tropical residual soils’ structure when subjected to different compaction conditions, thus providing means to improve field applications.