A laboratory study was performed to assess the geotechnical benefits of mixing construction and demolition screenings (“CDS”) with cement-amended dredged materials. Different sample mixes were prepared and tested for geotechnical characteristics. Soil index properties, drying curves, permeability, consolidation, swell, compaction, and strength were determined. Based on the results of this study, it can be concluded that the mix of CDS and dredged materials has similar engineering properties to those of the dredged materials. Nevertheless, the final product has lower water content than the stabilized dredged material (“SDM”), making it easier to compact and more manageable.

Structurally, the strength of the material is reduced slightly with the addition of CDS. However, this reduction is not significant for normal structural applications. With the addition of CDS to dredged materials, the permeability of the soil media increases, thereby making it more suitable for structural fills. Compaction, consolidation, and swell conditions of the mix are similar to those of the original SDM.

The authors of this study recommend the field mixing of CDS and SDM provided that additional field testing is conducted to determine the most suitable mixing procedures before implementation. It is also recommended that to avoid any reduction in strength, CDS be mixed with SDM at proportions not to exceed 20 percent. During the implementation, a monitoring plan should be designed to better determine and/or confirm the actual geotechnical conditions of the soil media in the field.