Glosey

Modern suspension bridges are constructed by increasing use of high performance tension members in which parallel wire strand (PWS) type, has been used as a suspender (hanger) cable for long-span suspension bridges. The main cables of a suspension bridge system support the total bridge deck load through these suspender cables. This study focuses on the thermal effects of open-air hydrocarbon type pool fires which may possibly outcome of a freighter truck. Even though fire load is still not accounted for in suspension bridge design, the literature concerning design standardization for fire hazard does not exist. Therefore, bridge engineers are mostly not sure of how to assess fire-induced damage due to a lack of experimental findings on bridge structural components such as suspender cables. Most of the research on bridge fires is based on the theoretical finite element models whose validity has not been checked experimentally. In this project, an experimental testing was conducted to have a full understanding in the behavior with regard to tensile strength and ductility of PWS cable system. The program includes static loading tests at ambient temperature and transient elevated temperature tests which specimens held at constant load level at 45% of ultimate load capacity and exposed to a realistic gasoline pool fire scenario until rupture. The results of the static loading tests confirm that the mechanism of the bonding between galvanized coated wire and both Zn–Cu casting and epoxy resin-based medium were appropriate for the sockets of a PWS specimen. Cable specimens at ambient temperature sufficiently withstood the %95 MUTS without complete pullout. The fire test results confirmed that the cable system failed early during fire. The cable surfaces indicate that the elevated temperatures changed from rupture to ductile failure. Such study indicates the necessity of fire protection application to bridge cables at least to a certain height.