SETTLEMENT REDUCTION OF DREDGED MARINE SOILS (DMS) ADMIXED WITH CEMENT & WASTE GRANULAR MATERIALS (WGM): 1-D COMPRESSIBILITY STUDY

Abstract

Dredged marine soils (DMS) are considered as geo-waste and commonly disposed far into the
sea. Environmental impacts raised from dredging such as turbidity and disturbance of marine ecosystem had
increased the social demand to reuse DMS in engineering application. Typically, DMS have low shear
strength and low bearing capacity. Hence, the DMS could be strengthened up by soil solidification. In present
study, waste granular materials (WGM) such as coal bottom ash (BA) and palm oil clinker (POC) were
utilized as additional binder to cement. The DMS were solidified with 3 series of admixtures; namely cement
and/or WGM. The factor that influenced the compressibility of the soil sample such as percentages of
admixtures were considered. Proportioned samples of 10, 15 and 20 % of cement, and/or 50 and 150 % of
WGM of dry weight of DMS were subjected to one-dimensional oedometer test. The test samples were cured
for 7 days in room temperature. Results show that cement- and WGM-admixed DMS have reduced the soil’s
compressibility considerably than the untreated sample. As expected, the cemented soil had significantly
reduced the settlement better than WGM-admixed soil. Hence, homogeneous samples of 15C50BA and
10C100POC produced almost similar reduction of compressibility as sample 20C. Therefore, reusing WGM
as partial replacement of cement in DMS could provide beneficial reuse of these materials.