Durabilidade a longo prazo de concretos produzidos com agregados de escória de aciaria BSSF

Abstract

The steel slag is a steel co-product with an expansive behavior, which, for incorporation into civil construction products, needs to go through stabilization processes. The process called BSSF (Baosteel's Slag Short Flow) is a technological novelty in Brazil in which large amounts of material can be cooled and stabilized in less time compared to conventional treatment. Thus, this work aims to identify the technical feasibility of concrete produced with the incorporation of steel slag aggregates stabilized by the BSSF process. The concrete mixes were developed for environmental aggressiveness class II, with a minimum strength of 25 MPa at 28 days. As materials, CP V-ARI, granitic gravel, quartz sand, BSSF steel slag and superplasticizer additive were used. The mechanical properties of axial compressive strength (ages 7, 28, 365 days) and static modulus of elasticity (ages 28, 91 and 365 days) were determined. Regarding the properties related to durability, volumetric stability over 365 days of observation, carbonation depth (age 28 days) and penetration of chloride ions (ages 28, 91 and 365 days) were evaluated. Finally, the potential for contamination by solubilization and leaching of the produced concrete was evaluated. In general, in relation to the reference mix, concretes with BSSF steel slag aggregates presented superior mechanical performance, similar durability characteristics, and low contamination potential (within the limits of NBR 10004). The EA40 and EA60 traits stand out, with the best mechanical results, without losses in terms of durability. However, the concretes produced are not suitable for applications in environments subject to chloride ion attacks, such as coastal regions.