To maintain adequate depth of commercial waterways, large quantities of earthen material are dredged and stored on undeveloped placement areas adjacent to the waterway. As dredge placement areas become overwhelmed, an environmental and financial sustainable solution for the reuse of dredged soil is prioritized. In this study, locally dredged material from the Sabine-Neches Waterway was used to explore the potential of dredged material in the production of compressed stabilized earth bricks (CSEBs) for small-scale structures in the region. CSEB mixture designs were developed containing fly ash (FA), Portland cement (PC), hydrated lime (HL), water (W), dredged material (DM), and natural and synthetic fibers. Optimized mixtures designs reached the recommended compressive strength of over 1200 psi. Results showed that that the addition of fibers reduced the compressive and flexural strength of the bricks, with a maximum compressive strength of 1394 psi with a corresponding flexural strength of 381 psi being obtained with fiberless dredge bricks. Multiple coating systems were also tested to increase the resistance of the bricks to weathering and erosion. Results showed that the use of coatings reduced water absorption and increased the bricks resistance to erosion, making them more adept in regions commonly subjected to flooding and heavy wind-driven rains.

Sediments are dredged from waterways to maintain maritime activities and prevent floods. Exorbitant amounts of money are budgeted for the removal of dredged material (DM) and its disposal in landfills. We investigated the potential for reuse of DM as a road construction material using so-called bio-enzyme products as stabilizing agents. To improve the mechanical properties of DM, such as compressive strength, compressibility, Atterberg limits and the California bearing ratio (CBR), mixtures of DM were tested with two different amounts of a commercially available bio-enzyme product, which yielded enzymatically stabilized dredged material (ESDM). Unconfined compressive strength (UCS), compaction and Atterberg limits were measured in accordance with ASTM specifications on all samples. Data show that the addition of bio-enzymes resulted in increases in UCS but did not affect the optimum moisture content (OMC), maximum dry unit weight or Atterberg limits of the DM. A comparative field study was carried out to evaluate the CBR of the CH subgrade before and after treatments with the bio-enzyme product and with lime as a traditional stabilizing agent. The results of the field study supported the laboratory findings. Based on these data and results from the literature, models predicting the effect of bio-enzyme treatments on the value of CBR and of UCS were developed statistically. These models also underlined the importance of the clay fraction and PI values for the improvement of the engineering properties of soil using bio-enzyme additives.

The deterioration of dams and levees is an increasing concern for both infrastructure integrity and environmental sustainability. The extensive repercussions, including the displacement of communities, underscore the imperative for sustainable interventions. This study addresses these challenges by investigating the stabilization of dredged material (DM) for diverse applications. Seven mixtures incorporating fly ash, lime, and cement were formulated. The Standard Compaction Test was used to determine optimal density–moisture conditions, which helped with brick fabrication. Bricks were tested for compressive strength over various curing periods, and the durability of the 28-day-cured samples was evaluated by performing water immersion tests following the New Mexico Code specifications. Scanning electron microscopy (SEM) was used to assess microstructural bonding. Results confirm that the inclusion of cementitious stabilizers modifies the material’s microstructure, resulting in enhancements of both strength and water resistance. Notably, the stabilized material demonstrates potential for use in non-fired brick manufacturing and as bridge stones for waterway erosion control. This dual-function application offers a sustainable and economically feasible approach to managing dredged materials.