Page 29 - New Trends in Green Construction

ANALYSIS OF MECHANICAL PROPERTIES AND DURABILITY OF SELF- COMPACTING CONCRETE WITH MINERAL ADDITIONS
Marcos A. S. Anjos, Evilane C. Farias; Ruan L. S. Ferreira, Cinthia M. Perdeneiras
Keywords: Durability, Precast industry, Chlorides, Self-compacting concrete, sustainability. 1. Introduction
Precast concrete industry appears as a necessity for the construction industrialization, acting both in reducing the materials wastes and construction time, besides present a better-quality control. Thus, this industry appears as an important ally in the manufacture of basic infrastructure elements, such as power distribution poles. However, an early deterioration of these conventional reinforced concrete power poles it is observed, when it is subjected to hard conditions, such as marine zones and heavily regions industrialized, showing as the most common pathological manifestation, the armature corrosion.
The concrete armature corrosion is a result of concrete carbonation process combined with the penetration of chloride ions, these processes can act separately or jointly. Supplementary cementitious materials can minimize this process, such as fly ash, metakaolin, and silica fume, which have the capacity to bind them to chloride ions, contributing significantly to prolong the useful life of armatures once that improve the concrete ability to resist the penetration of chloride ions (Wongkeo et al., 2014). The use of supplementary cementitious materials such as metakaolin can mitigate the problem, since these materials contribute significantly on the concrete's ability to resist penetration of chloride ions, consequently prolonging the useful life of the armature, since these materials have the ability to bind them to chloride ions (EFNARC, 2005).
This study aims to examine the durability of self-compacting concretes compared to conventional ones used in precast industry, which main product are power distribution poles. To this end, the properties in state hardened, as to compressive strength and diffusion coefficient of chloride ions were analyzed.
2. Material and methods
Four mixtures of concrete were produced, two of self-compacting concrete (SCC), and two of conventional concretes (CCV), as showed on Table I. The choice of conventional concrete features was based on features used by the precast industry. The definition of SCC features was based on studies of cement consumption reduction of SCC of Anjos et al. (2014) and EFNARC (2005). The properties of the SCC studied were evaluated through the tests of compressive strength (ABNT NBR 5739:2015) and diffusion of chloride (LNEC E-463:2004).
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New Trends in Green Construction