Environmental risks and vulnerabilities in coastal regions include the massive deposits of brown algae of the genus Sargassum in regions such as the Caribbean, Gulf of Mexico, and northern Brazil. Efforts have been made to turn this problem into an opportunity by seeking new uses for this biomass in the sectors of food, agriculture, health, biofuels, bioremediation, and civil construction. Thus, this study aimed to produce quantitative data for different end-of-life scenarios of the Sargassum algae, seeking for potential applications of this macroalgae in the civil construction sector. For this purpose, we conducted a life cycle assessment (LCA) study of the Sargassum algae, in its natural destination, and evaluated its potential impact. This evaluation was then compared to the possible impacts of alternatives to their end of life, such as landfill disposal, drying and grinding to use as fibers or particles, burning the biomass to generate energy and fly ash, using a consequential LCA and the indicators of the ReCiPe 2016 method. For each of the proposed scenarios, the functional unit of 1 kg of the three types of unprocessed Sargassum algae that are found in the Brazilian deposits (natans I, natans VIII, and fluitans) was considered separately, and also for a composition that is closer to that found in the Brazilian deposits (50% fluitans, 15% natans I, and 35% natans VIII). The results for both natural decomposition scenarios demonstrated a dominant contribution to the categories of impact for climate change, marine eutrophication, and land use, thus justifying the search for new initiatives for the use of the algae. The burning process showed a significant contribution to most of the indicators, with emphasis on the massive generation of particulate, inherent to the biomass burning process; however, it showed a reduction in the magnitude of climate change emissions from around 47% to less than 2%. Finally, the proposed scenario of processing Sargassum biomass to obtain particles presented prevalence of magnitude for potential impact in most of the proposed indicators, due to the processes with high electricity consumption, but keeping climate change emissions’ relative reduction from 47% to 6%. Thus, new studies may further investigate the potential of application of these materials in different products and components of civil construction.
This paper aims the evaluation of water absorption and compressive strength of calcined clay lightweight aggregates produced using alkaline activators. The characterization of ceramic material was made by techniques of liquid and plasticity limits, particle size analysis and chemical analysis. The specimens made from these ceramic materials and alkali activators (potassium silicate, sodium silicate with NaOH (15M), phosphoric acid, sodium silicate, potassium hydroxide and sodium hydroxide) were burned at temperatures of 600 °C and 900 °C and they were characterized by evaluation of water absorption and compressive strength. Results of this research indicates that the burn temperature has influence on the final properties of calcined clay lightweight aggregates and, when this aggregates were made using some activators, as sodium silicate, they presented lower values of water absorption and higher values of compressive strength, for both burn temperature, which can generate significant energetic gain in the aggregates production process).
The objective of this research was to evaluate the use of the Life Cycle Assessment methodology to assist decision-making in structural projects of reinforced concrete. Were studied structural models for an eight-story building, with classes of compressive strength (fck) of concrete ranging from 25 to 50 MPa. Also, were evaluated changes in the dimensions of structural elements, as well as the consumption of component materials of the structure. Results showed that the structural models for classes C40 obtained the best results for 67% of the categories of potential impacts assessed, with potential impact values ranging from 7.4% to 21.2%, including the possibility of saving 18 thousand kg of CO2 emitted. After carrying out an economic analysis, was observed that the structural model for the C40 concrete presented the optimal environmental-economic solution. The results of this research indicate the feasibility of using the Life Cycle Assessment methodology and economic analysis as tools to assist in decision-making during the design process of reinforced concrete structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.