Strength characteristics of hydraulically dredged mud slurry treated by flocculation-solidification combined method

Abstract Using conventional cement solidification method (CCSM) to form surface working platform (SWP) is a common option for resolving the accessibility problem at bottom mud dumping site. Nevertheless, if the dumping site is filled with hydraulically dredged mud slurry at extra high water content (EHW-MS), the treatment efficiency of CCSM is rather low or even marginal. In this paper, a new method, i.e. flocculation-solidification combined method (FSCM), is proposed for building SWP on EHW-MS dumping site more efficiently and economically. A large number of laboratory experiments are performed to confirm the superiority of FSCM and to evaluate the feasibility of two measures, i.e., adding retarder and replacing a portion of cement by quicklime, for FSCM optimization. Besides, the superiority of FSCM and the feasibility of the two measures are rationalized via analyzing the microstructural images and the intrinsic function mechanism of the additives admixed. It is shown that FSCM shows significant superiority over CCSM for EHW-MS treatment, and the solidification efficiency of FSCM is at least 4.8 times larger than that of CCSM. Adding appropriate amount of retarder and replacing an appropriate portion of cement by quicklime are two practically reasonable options for substantially improving the holistic performance of FSCM.