Corrosion of Steel H Piles in Decomposed Granite

To study the corrosion of steel H piles in a completely decomposed granite, piles were exposed by excavation 22 years after their installation. The thickness of the pile sections was measured. The average corrosion rate of the steel piles was estimated to be 0.011 mm/year, and the maximum corrosion rate was estimated to be 0.015–0.018 mm/year. The rates are low. The results confirm the conclusions derived from tests done in places with temperate climate that steel piles installed in undisturbed, native soils undergo little corrosion. Thus, such conclusions are also applicable to the completely decomposed granite in a place like Singapore with high year-round temperatures ranging from 25 to 35°C.