Effect of duct type, size, and embedment on bond behavior of post-tensioned mono-strand concrete members

Abstract

This research investigated the bond behaviour of mono-strand post tension systems with different duct types, sizes, and embedment length. Six specimens were considered in this study. Two different types of ducts were considered: plastic ducts and galvanic ducts. Two different duct sizes (9 cm × 4.2 cm and 6 cm × 2.4 cm), and embedment lengths (5 cm and 10 cm) for each duct type were considered in this study. Results showed that specimens with galvanic ducts had stronger bond than those with plastic ducts. In addition, it was found that extending the embedment length of the galvanic ducts form 5 cm to 10 cm improved the bond strength which was not the case for plastic ducts where the effect was null. Furthermore, specimens with galvanic ducts had greater bond strength when duct size was increased than those with plastic ducts.