Eco-friendly dredged material-cement bricks

Abstract

The increasing concerns about natural-resource depletion and environmental degradation have resulted in developing “green” products and switching to sustainable manufacturing processes. The conventional fired clay bricks and concrete masonry still play vital roles in the construction industry. However, the use of virgin materials and carbon emissions associated with their production have raised questions about their environmental sustainability. This study investigates the potential of using dredged material from a confined disposal facility (CDF) in Cleveland, Ohio, to fabricate eco-friendly bricks. The brick samples were made using mixtures of sand, sieved from the dredged material, with 8%, 10%, and 12%, by weight, of Type I/II cement, and compacting the samples using a pressure of 2 MPa or 4 MPa. The compressive strength, water absorption, and freeze–thaw resistance of the bricks were evaluated in the laboratory per American Society for Testing and Materials (ASTM) method C67. The compressive strength of the bricks ranged from 10.3 MPa to 17.2 MPa, whereas absorption ranged from 13% to 18%. The 50-cycle freeze–thaw (F-T) weight loss ranged from 0.1% to 0.4%, demonstrating that durable bricks, meeting the ASTM specifications (0.5% maximum F-T weight loss after 50 cycles), could be produced using the dredged material. Furthermore, a life cycle inventory of dredged material–cement brick (DM-CB) was established to compare its environmental impacts with conventional fired clay brick, concrete masonry units, and compressed stabilized brick. The DM-CB was observed to have the least embodied energy of 1.49 MJ/kg and an embodied greenhouse gas emission of 0.162 kg CO2e/kg, making it the eco-friendliest and environmentally sustainable product compared to conventional bricks.