ABSTRACT
The concrete specimens made from three types of cement binder with water-binder ratios of 0.35, 0.40 and 0.75 were exposed to chloride environment under different conditions: that is, exposed to 1) real seawater, 2) artificial seawater with pH-regulation, 3) artificial seawater without pH-regulation, 4) NaCl solution with a CΓ concentration similar to the seawater, and 5) NaCl solution with a Cl- concentration as about 10 times high as in the seawater. Some specimens were subjected to dry-wet cycles at the frequencies of 1:1, 3:1 and 5:1 weeks. The chloride profiles from different positions of a specimen were determined after one year exposure.
The results show that the highest penetration of chlorides appears at the position just close to the interface of wet-dry, on the dry side. The seawater exposure results in a lower chloride penetration. Wet-dry cycles do not increase the chloride penetration in the tidal zone. The exposure to a concentrated chloride solution results in a higher chloride penetration, but does not proportionally increase the chloride content in the concrete. The practical consequences of the results will be discussed in this paper.
