The durability of Prestressed High-strength Concrete (PHC) pipe pile is affected by the corrosion resistance of their metal ends, which depends on the material of end plate (EP), apron (AP) and pretensioned PC steel bar (PC). There are three kinds of EPs: cast steel, cold-bended steel and Q235A steel, which are widely used in pratical engineering. Their electrochemical corrosion behaviors in four typical simulated soil solutions including chloride salt soil, salina soil, neutral meadow soil and acid soil were investigated by natural immersion tests and electrochemical measurement techniqus. The results show that the corrosion rate of three kinds of EPs is smaller than that of PC and AP. The corrosion of PC and AP accelerated by cast steel EP is smaller than that by cold-bended steel and Q235A steel; but the corrosion resistance of cast steel EP is poor. There is contact galvanic corrosion between EP and AP, EP and PC in simulated soil solutions. In couple of EP/AP, AP is anode. Cast steel EP is anode when the galvanic couple of cast steel EP/ PC was in saline soil. In galvanic couples of cold-bended steel EP/PC and Q235A steel EP/PC, PC is anode. Contact corrosion quickens the damage of thin-walled AP and small-area PC, leading the premature failure of prestress. The corrosion of the existing metal ends in pratical engineering should be improved.
