ZDGITS in Gradbeni vestnik » Gradbeni vestnik » Gradbeni vestnik - december 2011 » HISTORICAL OVERVIEW OF PRESTRESSING SYSTEMS AND PERMANENT PRESTRESSED GROUND ANCHORS

Summary

A course of development of prestressing systems from first ideas and ineffective trials of prestressing to the development of applicable prestressing systems is presented. Such system has been for the first time used in practice at the strengthe-ning of the Cheurfas dam in Algeria. After the World War II the development and the expanded application of ground anchors continued all over the world. The durability of installed anchors turned out increasingly important in practice, which resulted in further development of effective corrosion protection. The practical experiences indicate that the comprehensive corrosion protection can be regarded as the appropriate form of permanent prestressed ground anchors protection, whereas such anchors have been used in our practice since 1997. However, the durability of such anchors can be ensured only in the case of careful execution according to the (in advance) certified installation details with the exactly achieved anchor head protection. Moreover, the condition of corrosion protection has to be permanently inspected and maintained in good condition during all anticipated anchors service life to prevent ingress of (contaminated) water to the steel parts of anchors.