Testing of Engineered Concrete for Biologically Dominated Coastal Restoration Mechanisms

Abstract

Oysterbreak (patent pending) technology has been used for development of biologically dominated engineered coastal restoration mechanisms. These devices have a number of advantages over traditional (usually rock or concrete based) coastal protection devices. They require less material and hence are less expensive, as well as lighter, resulting in slower sinking rates in sediment dominated areas such as coastal Louisiana or other deltaic areas. They also take advantage of and encourage natural reef-building actions of animals such as the eastern oyster, which can form large, stable concretions which provide habitat and protection for other species. The concrete required for such devices must provide surface area for colonization of desired organisms (e.g. the eastern oyster, Crassostrea virginica), but still provide sufficient strength to survive most wave conditions in coastal areas where they will be deployed. A series of tests focused on measuring properties of composite concretes, with components including agricultural byproducts (e.g. cottonseed), oyster shell, coastal sands and muds, and various concentrations of cement, sand and gravel. These tests included crush (compression) as well as bending tests and reveal a wide variety of mechanical properties. This information has been useful in designing different components of oysterbreak devices and optimizing such devices for coastal maintenance and reclamation.