Abstract

AGUIRRE, Ana María; GUTIERREZ, Ruby Mejía-de; RESTUCCI, Jean Paul  and  ALVARADO, Alexander. Study of a repair technique in carbonated blended mortars: Electrochemical re-alkalization. Dyna rev.fac.nac.minas [online]. 2016, vol.83, n.196, pp.93-99. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v83n196.49249.

The present article studies the influence of two pozzolanic additions, metakaolin (MK) and silica fume (SF), and the water/binder ratio (w/b) on the electrochemical re-alkalization (ER) of reinforced mortars as a technique to prevent reinforcement corrosion in carbonated concrete. Mixtures with a 10% (by weight) addition as a replacement for cement at w/b ratios of 0.45 and 0.65 were prepared. Test specimens were exposed to carbonation in a chamber under controlled conditions (1% CO₂, 65%RH, and 25°C), until reaching two levels of carbonation (50% and 100%). ER was applied for a period of 15 days using sodium carbonate as the electrolyte and a current density of 1 A/m². From the evaluated additions, MK is highlighted, which generated a resistance increase of 53.51% relative to that of the reference mixture and contributes to improvements of durability properties. Regarding the ER technique, the specimens with greater w/b ratios and partial carbonation were more effective.

Keywords : Carbonation; Electrochemical Re-alkalization; Blended Mortars; Silica Fume; Metakaolin.

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