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
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.