Winterization Methods in Post-tensioning Tendons

Abstract

Prestressed concrete elements are nowadays used in several applications very different from the standard concrete structures built in the past. In such cases, post-tensioning systems are by far the best choice, considering their great flexibility. To achieve the most effective results for post-tensioning applications, a dedicated careful design is always required, even more when special boundary conditions are given to the project, such as construction of a post-tensioned structure in arctic climates. This case is nowadays more and more common, due to research in new energy sources like the use of liquefied natural gas.

In these conditions, special winterization measures for the post-tensioning system have to be designed, in order to manage properly extreme low temperature conditions. Among post tensioning activities, ones of the most important requiring special winterization measures are the grouting operation, i.e. how to fill tendons’ ducts, and the pouring of special post-tensioning anchorages. In all these cases, heating of ducts and anchorages is required to guarantee proper grout curing.

The aim of this article is to provide a review of the possible winterization systems used in post-tensioning works, highlighting pros and cons for each one of them. Then, several applications used in job sites are presented.