FRACTURE BEHAVIOR OF STEEL STRANDS CORRODED IN CONCRETE CONTAMINATED WITH SALT

The specimens of corroded steel strands were presented by concrete members mixed with salt. By static tension tests with the specimens of corroded steel strands and flexural fatigue tests with the specimens of wires got from corroded steel strands, the fracture behavior is studied in this paper. The results show that, the fractures of wires of corroded steel strands under static tension include 3 basic modes and their combined modes, the basic modes are cleavage, fraise and cup; the fracture depends on the comparison between strain effect and strain resistance in pits; strain effect must increase near pits, and strain resistance decreases near pits when fracture is cleavage. The flexural fatigue fracture of wires of corroded steel strands shows an obvious anisotropic characteristic. When corrosion is slight, fatigue is the leading factor to corrosion fatigue and corrosion plays a role to assist nucleation of crack; when corrosion is severe, fracture is controlled by both corrosion and fatigue, and corrosion play the roles not only to assist nucleation of crack but also to accelerate the developing of crack.