Effects of Grout Condition on Galvanic Coupling and Hydrogen Absorption in Post-Tensioned Bridge Tendons Constructed with Galvanized Steel Ducts

There has been concern that prestressing structural steel contained within galvanized bridge tendon ducts may become embrittled due to excessive galvanic coupling with the duct which may be exacerbated by deficiencies within the grout fill. This work strives to quantify the level of galvanic coupling achievable as a function of grout conditions and assess whether such conditions may promote water reduction and hydrogen absorption. Experimental tendon assemblies were used to quantify galvanic coupling considering a single prestressing steel wire and various grout conditions. The results were related to more realistic geometric configurations by simulations considering a range of possible kinetic boundary conditions. A model is used to estimate the amount of hydrogen that may be absorbed as a function of time considering the coupling current density.