Evaluation of the suitability of dredged materials from river and coastal inlets as construction backfill

Abstract

Dredged materials from estuarine and coastal port areas are typically characterized by high plasticity, significant loss on ignition, and high expantion potential. Therefore, to assess the feasibility of using such materials as backfill, it is essential to conduct not only laboratory tests but also in-situ evaluations under real construction conditions. In this study, the research team carried out a pilot field trial over an area of 1000 m², using both dredged sludge and conventional backfill materials. The aim was to evaluate the applicability of dredged sediments by measuring key engineering indicators, including the compaction coefficient (K), California Bearing Ratio (CBR), and elastic modulus (E) of the constructed layers. The results indicate that when dredged materials from estuarine and port areas are stabilized with additives such as cement and ground granulated blast furnace slag (GGBFS), the improved materials fully meet the technical standards for subgrade and foundation construction as specified in TCVN 9436:2012 and TCVN 10379:2014 at various specification levels. These findings support the potential for widespread application of stabilized dredged materials in practical infrastructure development.