# Development of Fiber Reinforced Sustainable Dredge Bricks
## 1 Introduction  
Waterways have a constant need to dredge channels for maintenance and must deposit the dredged material (DM) in placement areas making dredge waste management a burden to port and waterway facilities with the potential to restrict expansion capabilities. Waterway management were forced to use placement areas for dredge material storage as bans on ocean dumping became widespread more than twenty years ago causing facilities across the world to try to tackle this societal challenge [1, 2, 3]. Placement areas everywhere are over stretched making the management of dredged material a significant problem. Dredged soil has traditionally had very limited practical uses because of its undesirable material properties, however because it is becoming a major concern, the reuse of dredged material has been the object of some investigation by geotechnical and environmental professionals in the industry, none resulting in a cost-effective solution [1, 2, 3, 4]. Our research motivation is therefore to find a novel potential commercial use for dredge material instead of simply disposing of the soil in placement areas. The method we report on is based on different suggestions found in the literature. Using dredge material to produce earth fill has been proposed with some degree of success [3, 5], however, another more value-adding possibility is to use dredge materialto develop compressed stabilized earth bricks (CSEB). CSEB are easy to manufacture and are relatively uncomplicated to produce in bulk. CSEB can be manufactured using readily available materials and using low energy since they do not need to be fired in a high temperature kiln making them an economically viable alternative in the construction industry. The potential positive impacts for developing viable bricks from dredge material are numerous including the conservation of land that would otherwise be used as a dredge landfill saving taxpayers money and preventing the displacement of local wildlife. In fact, [PERSON] and [PERSON] report an industrial scale experiment of the fabrication of dredge material bricks [6]. If the dredge CSEB prove to be cheaper than typical concrete masonry units (CMU), a positive implication is the reduction of cement use in local construction projects. In fact, since the cement industry contributes 5% of worldwide emission of CO\({}_{2}\), the use of dredge bricks instead of typical CMUs would greatly benefit the environment because of the reduction in carbon emissions that utilizing less cement entails [7]. The best quality CSEB use soil having optimum compaction and construction properties. In particular, the plasticity index should be between 15 and 30 while the dry unit weight should be within the values of 102 lb/ft3 and 140 lb/ft3 [8]. CSEB made from such materials will increase in strength over a period of time, not only because the cementation of the material increases the strength properties, but water evaporation will cause the clay particles to move closer to one another due to an increase in capillary forces. This decrease in water content also increases the modulus of elasticity of the soil along with its compressive strength [9]. [PERSON] et al. studied the most efficient and economical ways to recycle dredged sediment by designing partition blocks. These partition blocks were tested with mixtures of Portland Cement, ground granulated blast-furnace slag, incinerated sewage sludge ash, dredge sediment, and recycled fine and coarse aggregates. Each mixture design contained 20% binder. Compression tests were performed on each mixture and found that after 7 days all mixtures achieved compressive strength of at least 1987 psi, which was well above the standard for partition bricks. The mixture with the highest strength was 16% Portland Cement, 4% ground granulated blast-furnace slag, 16% dredge sediment, 16% fine aggregate, and 48% coarse aggregate [10]. This study suggests that optimization of CSEB may require a variety of stabilizing agents such a Portland cement (PC), fly ash (FA), and lime (L).