Date of Award
Master of Science
Konstantin Sobolev, Benjamin Church, Habib Tabatabai
Beneficial Uses, Dredged Material, Geopolymer Concrete
Dredging harbors and rivers are necessary to maintain the appropriate water depth for navigation. However the disposal facilities for storing dredged materials around the U.S. Great Lakes are at or near their capacities and finding beneficial uses for these materials is a major concern. On the other hand, carbon emission and global warming have become the greatest environmental issues during the last decade. Cement manufacturing is a major contributor to CO2 release into the atmosphere. The objective of this study was to develop a low-cost, environment-friendly geopolymer concrete paste with dredged materials as a substantial mix ingredient. Geopolymer concrete does not use the portland cement binder. Dredged materials used in this study were obtained from the confined disposal facility at the Port of Milwaukee, Wisconsin. Different geo-polymer paste mix designs were tested to obtain optimum compressive strength while maximizing the use of dredged materials. Paste mix ingredients included dredged materials, Class F fly ash, and a combination of sodium hydroxide and sodium silicate liquids (alkali liquids). The ratios of alkali liquids to fly ash and sodium silicate to sodium hydroxide used in the test mixes were selected chosen based on work by Rangan et al. (2005). The mixtures were placed in a 60˚C oven for 24 hours followed by air curing at room temperature. Compressive strength test were performed on 2-in (51mm) cube specimens. Results indicate that compressive strength exceeding 20 MPa was achievable (at an age of 14 days) with dredged materials comprising up to 40% of the total mass of the geopolymer mixture. Therefore, beneficial use of substantial quantities of dredged materials is possible in geopolymer concrete applications. Previous research has shown that geopolymer concretes can also reduce leaching of contaminants that may exist in mix ingredients.
Dashti, Sara, "Experimental Evaluation of Beneficial Use of Lake Michigan Dredged Materials in Flyash Based Geopolymer Concrete" (2015). Theses and Dissertations. 1046.