Flocculant effects on fluidity and strength behavior of cemented dredged clay with high water content

Abstract

The dredged clay (DC) could not be directly reutilized for its extra-high water content. So, the dewatering is needed before further improvement. At present, the commonly used self-weight sedimentation and natural air-drying are often difficult to meet the engineering requirements and time-consuming, thus chemical flocculants are used to improve the dewatering process for their excellent flocculation in recent years. In this study, the flocculant effects on the fluidity and strength behavior of cement-treated dredged clay, are investigated based on experimental results. For the dredged clay, its fluidity firstly increases with the increasing content of FeCl₃ and Chitosan, and then reaches a stable value; while the addition of PAM would decrease its fluidity. Compared with the dredged clay, relatively small changes in the fluidity of solidified dredged clay are found with the addition of flocculants. The flocculant with a suitable dosage has an overall enhancement in the undrained strength of solidified soils. The flocculation of dredged clay/cemented clay induced by the flocculant is responsible for changes in the fluidity and undrained strength. For flocculants used in this study, the appropriate content corresponding to the target fluidity and maximum strength is in the range of 0.1% to 0.5%.

Keywords:

• Dredged clay
• flocculant
• solidification
• fluidity
• unconfined compressive strength

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the Natural Science Foundation of Jiangsu Province (Grants No BK20170477), the National Natural Science Foundation of China (Grants No 51808481, 51778556 and 51978597).