Anchorage behavior of grouting sleeves under uniaxial and cyclic loading-A comparative study of the internal structure of sleeves

Abstract

Grouting sleeves as one of connection methods of splice rebars are used widely in prefabricated construction. The performance of sleeve connection has a significant influence on the seismic performance of prefabricated structure. The internal structure of sleeve is a key factor affecting the bond performance of the sleeves. In this study, a new kind of sleeve was developed, where internal threads and wedges were the main variables studied contrastively. Three specifications of threads and wedges were designed and 10 groups (30 specimens) were tested under uniaxial loading, cyclic loading at high stress and cyclic loading at large strain. The results of failure mode, load-displacement relation, load-strain relation and internal damage phenomenon were analyzed comparatively. The results showed that both threads and wedges can improve the anchoring performance of sleeves, while the specimens with threads exhibit a more ideal stress distribution and a lower damage compared to the ones with wedges. Furthermore, the combination of these two methods showed excellent mechanical properties. The threads size and the wedges slope angle of sleeves influence the stress distribution and damage state of grouting materials greatly. For the rebar with diameter of 12 mm, threads with a height Ht of 1.5 mm and the wedges that dw is 1 mm–2 mm were suggested, and the cost was acceptable.