ABSTRACT
Normal portland cement concretes containing additional KOH up to 1.5% were water cured for 28 days. Later these were stored in 50% relative humidity condition till 90 days. These were tested for carbonation under accelerated condition. Potassium hydroxide addition decreased the concrete strength, which was 35–40% lower than the reference concrete at 28 days. The addition of alkali lowered the resistance of concrete to carbonation significantly. A chemical effect on the concrete matrix structure by the additional alkali is believed to be the reason for this. The carbonation process of concrete is theoretically discussed.
