DECIV - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/497
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Item Blast oxygen furnace slag as chemical soil stabilizer for use in roads.(2017) Diniz, Dayse Horta; Carvalho, José Maria Franco de; Mendes, Júlia Castro; Peixoto, Ricardo André FiorottiStabilization of poor soils is a technique that can improve engineering properties for road building. Chemical stabilizers such as cement and lime are commonly employed. However, environmental issues and costs involving the production of these materials are making their utilization questionable. Brazil has the fourth largest road network in the world, but only 12% of these roads are paved, which indicates a great need for transport infrastructure at low cost and with good technical and environmental performance. This work proposes the use of basic oxygen furnace steel slag (BOFS) as a chemical soil stabilizer. Sixteen different mixtures of lime, cement, and processed BOFS were tested and compared. The parameters evaluated were unconfined compressive strength, diametrical tensile strength, California bearing ratio, expansibility, and environmental contamination. Results indicate that soils stabilized with BOFS have the same environmental classification as soils stabilized with cement and lime. The BOFS fines successfully stabilized the studied soil, leading to an increase in CBR values of up to 230% along with a decrease in expansibility. The best mechanical performance was observed in the mixture with 15% BOFS and 5% cement by weight, which indicates high performance with high content of BOFS and low cement consumption.Item Ladle furnace slag as binder for cement-based composites.(2017) Marinho, Ana Luiza Borges; Santos, Carina Miranda Mol; Carvalho, José Maria Franco de; Mendes, Júlia Castro; Brigolini, Guilherme Jorge; Peixoto, Ricardo André FiorottiIn recent years, the environmental facet of industrial waste management has become imperative. The recycling of these residues in the civil construction sector is growing, since both industries have developed an increasing concern for the exhaustion of natural resources. In this scenario, one example is the ladle furnace slag (LFS), a by-product of the secondary refining of steel. It is mainly composed of calcium and calcium magnesium silicates. Thus, this research aims to develop a sustainable binder obtained from LFS as a substitution of hydraulic lime. In this sense, an extensive characterization of the LFS was carried out in its raw and processed forms. Subsequently, all the requirements for hydrated lime and hydraulic lime were verified according to Brazilian and Portuguese standards. Finally, mortars for coating and laying were produced with portland cement, lime, and the sustainable binder, and their main properties were evaluated in the fresh and hardened states. The chemical and mechanical properties of the sustainable binder were closer to those of the hydraulic limes. The obtained results indicate the technical feasibility of the use of LFS as binder for mortars in the replacement of lime.Item Using iron ore tailings from tailing dams as road material.(2016) Bastos, Lucas Augusto de Castro; Silva, Gabriela Cordeiro; Mendes, Júlia Castro; Peixoto, Ricardo André FiorottiThe present work aims to evaluate the feasibility of iron ore tailings from tailing dams as an alternative material for road infrastructure. The iron ore tailings were characterized according to their chemical, mineralogical, environmental, and physical properties. Subsequently, the tailings were chemically stabilized using cement, lime, or steelmaking slag as binder. The tailing-cement, tailing-lime, and tailing-slag mixtures studied consisted of 1, 2, 5, and 10% binder content, each. The characterization methodology included chemical and mineralogical analysis through X-ray fluorescence and diffraction; environmental analysis with leaching and dissolution tests; evaluation of compaction curves; California bearing ratio (CBR) tests and expansion assessment; compressive strength, with curing in moisture chamber or at open air; water absorption; and evaluation of durability of the mixtures. Overall, the results indicate that the iron ore tailings are a feasible solution for use as layers for road paving, once chemically stabilized. The cement is the most efficient stabilizer among the studied binders. The slag-tailing sample did not endure the durability cycles; thus, further research is required to ensure its technical feasibility. DOI: 10.1061/ (ASCE)MT.1943-5533.0001613. © 2016 American Society of Civil Engineers.