Abstract:
This research investigates the effects of palm oil fuel ash on compressive strength, chloride penetration, and steel corrosion of concrete after being exposed to the marine environment for 7 years. Water-to-binder ratios (W/C) were carried at 0.40, 0.45 and 0.50. Palm oil fuel ash to partially replace Portland cement type I at the percentages of 0, 15, 25, 35 and 50 by weight of binder. The 200-mm concrete cube specimens were cast and steel bars with 12-mm diameter and 50 mm in length were embedded with the covering depth of 10, 20 and 50 mm. Then the cylindrical specimens of 100-mm in diameter and 200-mm in height were cast for testing compressive strength then cured in fresh water for 28 days. Subsequently, the specimens were tested to determine the compressive strength, the chloride penetration, and the steel corrosion after being exposed to tidal zone for 7 years. The results indicated that chloride penetration and steel corrosion clearly decreased with replacing palm oil fuel ash is less than 25% by weight of binder including the increased of compressive strength. However, with a high volume of palm oil fuel ash replacement (up to 50% by weight of binder) did not well prevent the chloride resistance and steel corrosion. This study found that concretes with the palm oil fuel ash replacement of 15 to 35% by weight of binder with a W/B ratio of 0.40 can be efficiently employed to enhance the durability of concrete structures in seawater. Because of they provide the highest compressive strength and lowest chloride penetration and steel corrosion in concrete