The effect ofwet–dry cycles in tapwater and in 3.5% NaCl solution on the passivating products of galvanized steel after concrete carbonation was investigated. The results show that carbonation destroys the passivating layer of calcium hydroxyzincate with the formation of the amorphous products ZnCO3 and Zn5(CO3)2(OH)6, which are also protective. The exposure to wet–dry cycles in tap water after concrete carbonation does not significantly increase the corrosion rate of the galvanized steel with respect to the values measured in non-carbonated concrete. On the contrary, the exposure to chloride solution after concrete carbonation leads to a marked decrease in the chloride threshold for galvanized steel corrosion with respect to that found in non-carbonated concrete.
Corrosion resistance of galvanized steel reinforcements in carbonated concrete: effect of wet–dry cycles in tap water and in chloride solution on the passivating layer / Roventi, Gabriella; Bellezze, Tiziano; Giuliani, Giampaolo; Conti, Carla. - In: CEMENT AND CONCRETE RESEARCH. - ISSN 0008-8846. - ELETTRONICO. - 65:11(2014), pp. 76-84. [10.1016/j.cemconres.2014.07.014]
Corrosion resistance of galvanized steel reinforcements in carbonated concrete: effect of wet–dry cycles in tap water and in chloride solution on the passivating layer
ROVENTI, Gabriella;BELLEZZE, Tiziano;GIULIANI, Giampaolo;CONTI, CARLA
2014-01-01
Abstract
The effect ofwet–dry cycles in tapwater and in 3.5% NaCl solution on the passivating products of galvanized steel after concrete carbonation was investigated. The results show that carbonation destroys the passivating layer of calcium hydroxyzincate with the formation of the amorphous products ZnCO3 and Zn5(CO3)2(OH)6, which are also protective. The exposure to wet–dry cycles in tap water after concrete carbonation does not significantly increase the corrosion rate of the galvanized steel with respect to the values measured in non-carbonated concrete. On the contrary, the exposure to chloride solution after concrete carbonation leads to a marked decrease in the chloride threshold for galvanized steel corrosion with respect to that found in non-carbonated concrete.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.