CORROSION BEHAVIOR OF STEEL IN HIGH-ALUMINA CEMENT MORTAR CURED AT 5,25 AND 55-DEGREES-C - CHEMICAL AND PHYSICAL FACTORS

Citation
A. Macias et al., CORROSION BEHAVIOR OF STEEL IN HIGH-ALUMINA CEMENT MORTAR CURED AT 5,25 AND 55-DEGREES-C - CHEMICAL AND PHYSICAL FACTORS, Journal of Materials Science, 31(9), 1996, pp. 2279-2289
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science
ISSN journal
0022-2461
Volume
31
Issue
9
Year of publication
1996
Pages
2279 - 2289
Database
ISI
SICI code
0022-2461(1996)31:9<2279:CBOSIH>2.0.ZU;2-R
Abstract
The corrosion behaviour of embedded steel was related to the compositi on of the pore phase in equilibrium with the hydrated phases and the p orosity of the high alumina cement mortars subsequent to curing at 5, 25 and 55 degrees C. The corrosion of reinforcements was evaluated by electrochemical techniques. The effect on corrosion of 3% by weight of cement of NaCl, added during the mixing process, and of the accelerat ed carbonation of mortars in CO2 atmosphere were also determined. The pH value and the chemical composition of pore fluid of plain high alum ina cement (HAC) mortar cured at all three temperatures suggested that the embedded steel was in a passivated state. The resistance of HAC t o carbonation and its greater potential for chloride binding by chloro aluminate formation are believed to make HAC inherently more protectiv e to steel, relative to normal Portland cement, during ingress of chlo ride from external sources. High corrosion rates reported in literatur e for steel embedded in HAC may be attributable to bad practice, not t o lack of passivity.