Research on "Rotten Feet" Phenomenon in Cast-in-place Reinforced Concrete Columns of Liu Lu Apartment

"Rotten feet" phenomenon, represented by drain holes and exposed reinforcement, occurs in the cast-in-place concrete columns of Liu Lu Apartment. This paper analyzes the reasons of this phenomenon. Main reasons include concrete disintegration, which is represented by mortar and gravel separation; too much concrete unloading at one-time and inadequate vibration; inappropriate selection of concrete mix ratios and others. Corresponding preventive ways and countermeasures are provided in this paper. These methods of prevention and treatment are also applicable to drain holes and exposed reinforcement in beams and plates.