Corrosion evaluation of post-tensioned tendons with dissimilar grout

Corrosion evaluation of post-tensioned tendons with dissimilar grout Conference

Lau, K, Paredes, M, Rafols, JC. (2012). Corrosion evaluation of post-tensioned tendons with dissimilar grout . 7 5712-5727.

The presence of voids in the grout of post-tensioned tendon ducts provides conditions whereby corrosion development may occur. The causes of the voids have been attributed to development of bleed water during grouting and subsequent re-absorption or evaporation from the grout. Poor grouting during construction is of concern as well. Recent early corrosion failure of tendons and ongoing tendon repair of a bridge (constructed with grout conforming to low bleeding requirements) has led to interest in gauging the extent to which corrosion may develop for repaired post-tensioned systems where void spaces (or segregated grout) have been re-grouted with dissimilar grouting materials. Preliminary results on the application of electrochemical impedance spectroscopy (EIS) to characterize grout properties and corrosion condition of strand after repair of PT systems with dissimilar grouting materials are presented. ©2012 by NACE International.