Mechanism of bonding between Zn–Al-coated wires and Zn–Cu alloy casting medium in hot casting socket terminations for large bridge cables

•The bonding mechanism of large bridge cable sockets is investigated.•Poor cleaning of the wire causes premature failure of the bonding in sockets.•The wedging effect increases the bonding between the wire and casting medium.•High casting temperature in excess of 500 °C ensures reliable bonding resistance.•The bonding strength of Zn/Al-coated wire and Zn/Cu medium is higher than 20 MPa.

In this paper, we describe the mechanism of the bonding between the Zn–Al-coated wires and Zn–Cu alloy casting medium of the socket terminations of prefabricated parallel wire strands (PPWSs) used for the main cable of a suspension bridge. Single wire pullout tests were conducted using various design conditions to investigate the effects of the embedded length, cavity angle, cleanliness of the wire, and casting temperature on the hot casting socket terminations. Full-scale cable pullout tests were also conducted to clarify the bonding mechanism in real cable sockets. The test results revealed that the bonding resistance of the socket termination considered in this study was comparable to that of traditional galvanized-wire casting sockets, which confirmed that the new combination could be effectively used for the main cable of a suspension bridge.