Consolidation behavior and microstructure properties of cement-treated dredged soil during the stress curing

Abstract

The curing stress can significantly improve the engineering properties of cement-treated dredged soil (CDS). Based on the large-scale consolidation tests, this study investigated the settlement pattern of CDS under the curing stress of 0–100 kPa, and the pressure dissipation and chemical properties of pore water were also explored. The results showed that the application of curing stress greatly accelerated the settlement of CDS and significantly reduced its void ratio, however, the consolidation efficiency gradually weakened with the increase of cement content. With the curing stress increasing, the completion time of primary settlement of CDS was prolonged, and the pH and EC values of the pore water both gradually increased. The void-ratio reduction of CDS during stress curing arises from the combined effect of mechanical compression and chemical filling, and the two effects have different contributions to the reduction of void ratio at different consolidation stages. Moreover, the effects of curing stress on the microstructure of CDS were also investigated by the scanning electron microscopy (SEM) and mercury intrusion porosimeter (MIP) tests. The results show that with the curing stress applied, the volume of large pore in CDS significantly decreased and the structure became denser.

Keywords:

• Dredged soil
• cement-treated
• stress curing
• void ratio
• consolidation
• microstructure

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the National Science Foundation for Distinguished Young Scholars (51625903); National Natural Science Foundation of China/Hong Kong Research Grants Council Joint Research Scheme (51861165104); Youth Innovation Promotion Association CAS (2017376); Yixing “Taodu Talent” program of Technology Innovation and Entrepreneurship leading Talent Project (CXTD201601C).