Review on the Determination of Sulfate Ion Concentrations in Deficient Post-Tensioned Grouts

摘要

Severe corrosion of steel strand in post-tensioned tendons developed in several bridges in Florida and Virginia in the 1990s and recently in the 2010s. The corrosion that developed in the 2010s was associated with segregated grout that was characterized by elevated sulfate concentrations and alkaline pore water pH. Recent specifications by the Florida Department of Transportation include sulfate measurements. However, the characteristics of the grout can be significantly different depending on the level of grout deficiency. The paper reviews different methods to sample the pore water of physically deficient grout to measure the free sulfate ion concentration.