PSI - Issue 11

Stefanie A. Campos et al. / Procedia Structural Integrity 11 (2018) 145–152 Stefanie A. Campos et al./ Structural Integrity Procedia 00 (2018) 000–000

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hydration phase. The coating humidity was analyzed at 28 days. Were observed the values of 4.68%, 4.18%, 5.61% and 5.42% for the mixes of 0, 10, 20 and 30%, respectively. The average coating moisture is higher in mixtures with higher sand substitution due to the higher porosity of the recycled aggregate, which absorbs more water. Also, the shape of rupture of the 48 specimens was analyzed. It can be observed that most of the samples broke in mortar, showing that measured resistance values refer to the mortar used and not to the substrate. The ruptures in coating mortar are due to the presence of voids or failures in layer application. The coating mortars were analyzed for the occurrence of cracks at 28 days in samples used in the test of tensile bond strength. No cracks were observed at 28 days in any of the panels run for each mix. For use of the steel slag as an aggregate in substitution of sand, initially, it must be observed that steel slag is obtained from steel mill as a large aggregate and its use as a fine aggregate generates a cost of grinding due to its abrasion loss index Los Angeles of 22.8%. In addition to reduction of granulometry, sieving must also be done to adjust the grain size curve to that of sand, for effective replacement. These are two costly processes required to make the use of this recycled material as a fine aggregate possible. In the general analysis of slag expansion, low values of expandability were obtained. However, there are no normative values to allow the comparison of these results with others previously obtained, and future studies are necessary for a better analysis of the expandability of this material. It was observed that the higher the substitution content of sand for the slag, the higher the density obtained. In analysis of mortar resistances, the traces with 10% and 20% of substitution had a similar performance to the reference trace, while the 30% mix obtained a lower performance in compressive strength. Regarding the tensile strength, all traces analyzed obtained a good performance with resistances close to 0.3 MPa and could be used as a coating of internal walls with paint finish. In analysis of mortar coatings at 28 days, no cracks were found in any of executed mixes. As shown above, it can be concluded that steel slag has technical feasibility to be used as a fine aggregate in replacement of sand in execution of mortar coatings with substitution of up to 20% sand for slag, since from this percentage, there is a decrease in compressive strength and increase in cement consumption. Associação Brasileira de Normas Técnicas (ABNT). NBR 15577-01: Aggregates – Alkali reactivity of aggregates. Part 1: Guide for the evaluation of potential reactivity of aggregates and preventive measures for its use in concrete. Rio de Janeiro, 2008 (In portuguese). Associação Brasileira de Normas Técnicas (ABNT). NBR 13528: Render made of inorganic mortars applied on walls – Determination of tensile bond strength. Rio de Janeiro, 2010 (In portuguese). Bessa, I.S. et. al . Analysis of the influence of size on the shape properties of analyzed aggregates through digital image processing. 8º Congresso Brasileiro de Rodovias e Concessões, Santos, SP, 2013 (In portuguese). Calmon, J. L. Industrial and Agricultural Waste. Civil Construction Materials and Principles of Materials Science and Engineering. ed. G. C. Isaias, São Paulo: IBRACON, 2007, 2v (In portuguese). Centro de Gestão de Estudos Estratégicos (CGEE). Overview of Steel Sector. Brasília, 2008 (In portuguese). Centro de Gestão de Estudos Estratégicos (CGEE). Steel industry in Brazil 2010-2025: Grants for decision making. Brasília, 2010 (In portuguese). Departamento Nacional de Infraestrutura de Transportes (DNIT). Standard DNIT 113. Road paving - Artificial aggregate - Evaluation of the expansion potential of the steel slag - Test method. Rio de Janeiro, 2009 (In portuguese). Gumieri, A. G. Study of the technical feasibility of the use of slag from the LD process as addition in cement. 2002. 226 p. Tese (Doutorado em Engenharia Civil) –Escola de Engenharia, Universidade Federal do Rio Grande do Sul, Porto Alegre (In portuguese). John, V. M. Recycling of waste in construction: contribution to research and development methodology. 2000. 113p. Tese (Livre Docência) – Escola Politécnica de São Paulo, Universidade de São Paulo, São Paulo, 2000 (In portuguese). Machado, A. T. Comparative study of the test methods for evaluation of the expansion of steel slag. 2000. 153 f. Dissertação (Mestrado em Engenharia Civil) - Universidade de São Paulo, São Paulo, 2000 (In portuguese). Machado, A. T. et al. The use of steel slag as an aggregate in civil construction. IX Encontro Nacional de Tecnologia do Ambiente Construído, Foz do Iguaçu, 2002 (In portuguese). Menezes, R. R. et al. Granite sawing waste recycling for mortar production. Cerâmica, v. 55, p. 263-270, 2009. 4. Conclusion References Associação Brasileira de Normas Técnicas (ABNT). NBR 13281: Mortars applied on walls and ceilings – Requirements. Rio de Janeiro, 2005 (In portuguese). Associação Brasileira de Normas Técnicas (ABNT). NBR 11582: Portland Cement – Determination of soundness by Le Chatelier test. Rio de Janeiro, 2016 (In portuguese).