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Abstract. In present time, dredged marine soils (DMS) are generally considered as geo-waste in Malaysia. It is also known to contain high value of water and low shear strength. Lightly solidified soils such as soilcement slurry and flowable fill are known as controlled low strength materials (CLSM). On site, the CLSM was tested for its consistency by using an open-ended cylinder pipe. The vertical and lateral displacement from the test would determine the quality and workability of the CLSM. In this study, manufactured kaolin powder was mixed with different percentages of water. Cement was also added to compare the natural soil with solidified soil samples. There are two methods of flowability test used, namely the conventional lift method and innovative drop method. The lateral displacement or soil spread diameter values were recorded and averaged. Tests showed that the soil spread diameter corresponded almost linear with the increasing amount of water. The binder-added samples show no significant difference with non-binder sample. Also, the mixing water content and percentage of fines had influenced the soil spread diameter.

Abstract. Dredged marine soil (DMS) is considered as weak and soft problematic soil. It is possible to give this type of soil a second life if only its geotechnical properties are improved. Infusing soil with solidification agent is the common practice of soil improvement. This study uses binder and waste granular material (WGM) such as cement, bottom ash (BA) and palm oil clinker (POC). The aforementioned materials are capable to fortify the poor features of the soil. Series numbers of soil bed samples were tested for its shear strength and shear resistance. Test results show that the mentioned soil parameters were corresponded with each other. In short, geo-waste and biomass materials are possible to be reused instead of being discarded.

Dredged marine soils that obtained from dredging work were characterize as geo-waste, which is prone to be dumped rather than to be reused. This type of soil is high in compressibility and low in load bearing capacity. The engineering properties of this soft soil can be improve via soil solidification method. Cement is the common hydraulic binder used in soil solidification, were found to generate the emission of greenhouse gasses (GHG), particularly carbon dioxide (CO2) which also had affected the earth's atmosphere. Therefore, there has been an increasing interest in using alternate pozzolanic materials such as waste granular materials (WGM) to fully or partially substituted the use of cement in soil solidification. WGM such as coal bottom ash (BA) and palm oil clinker (POC) were opted due to its pozzolanic properties. Prior to the planning of reclamation work using DMS admixed with conventional and/or alternate pozzolanic materials, the consolidation characteristics of the admixed materials must be acknowledged. Hence, the present study will examine the amount of settlement and coefficient of permeability (k) of DMS treated with cement and/or WGM in laboratory-scale experiments. Samples were prepared in various proportion in order to examine the individual effect of the cement and/or alternate pozzolanic materials on compressibility and permeability. For cement-admixed DMS, sample with 20 % of cement have significantly reduced the settlement than untreated and 10 % cemented DMS. For WGM-admixed DMS, the initial void ratio is low as compared to the untreated DMS due to the rearrangement of soil particles, which is densely packed. For cement-WGM-admixed DMS, samples of 15C50BA and 15C50POC displayed significant settlement reduction than 10C100BA, 10C100POC and untreated samples.

The use of fiber as soil reinforcement is not new in civil engineering field. In the earlier times, rice straw was mixed together with mud or clay to produce construction materials such as brick and concrete. Conventional concrete mix without fiber tends to exhibit brittleness behaviour. Hence, there is a growing attention on using current reinforcement materials such as steel, polypropylene and glass fibers. It is reported that fiber in concrete provide bridging effect, which transfer and distribute load evenly, thus increasing ductility. Now, similar concept of fiber inclusion in concrete can be applied to the case of problematic soil. The addition of chemical additives such as cement in soil resulted with stiffness and brittleness. As solution, numerous studies have shown that the fiber inclusion in soil have increased strength, permeability and ductility. Due to the many studies of fibre-reinforced soil related to its shear strength, the present study will investigate the compressibility behaviour of the fibre-reinforced soil through oedometer test. In this study, the dredged marine soil (DMS) was mixed together with 0.25, 0.5, 0.75 and 1 % of polypropylene (PP) fiber. Two conditions of soil, namely high water content (1.40LL) and low water content (0.90LL) were tested. Samples with 0.90LL water content show great reduction of settlement than samples with 1.40LL water content. The outcome of this study will suggest the beneficial reuse of DMS for engineering application such as backfill material, land reclamation or clay liner for landfills.