Process stabilization–solidification (PSS) is a convenient technology for amending high water content dredged sediments (DS) with binders. The PSS equipment comprises of a chassis that carries a pugmill and silos of up to four binders. Primary binders such as cement can be supplemented with pozzolanas materials. In this study, physicochemical interactions of single and composite (ternary) binders on strength development of treated DS are examined based on laboratory and a large–scale field tests. The findings of this study show that fixed amount of cement content at increasing initial water content of the DS contribute to decreased level of calcium ions in the blend. Organic matter in the DS retains calcium ions liberated during cement hydration. This causes delay in formation of calcium hydroxide (CH), nucleation and crystallization of calcium silicate hydrates (CSH). Delay in the formation of CH hinders pozzolanic reaction of mineral admixture. Furthermore, increased amount of free water surrounding the stabilized mass causes weakening effect on CSH bond and pH neutralization. It is concluded that strength development of dredged sediments will depend on the amount of cement in the blend in relation to mineral admixture, initial water content of the DS, and the amount of organic matters.