Einfluss der Rippengeometrie auf den Verbund von Betonstahl aus Ringen

Influence of rib geometry on the bond strength of reinforcing steel from coils. Reinforcing steel in coils has a modified rib geometry with wide ribs compared to conventional rebars, in order to ensure proper bending and straightening. The combination of small rib spacing and wide ribs result in reduced bond strength even though the rebars have a large relative rib area. To meet this concern, an experimental study with pull-out tests was carried out to investigate the influence of rib geometry on the bond strength of reinforcing steel from coils. In pull-out tests, significantly lower bond strength was obtained with reinforcing steel from coils compared with conventional straight reinforcing bars. By analyzing a test database with lap splice and anchorage tests from literature, a noticeable influence of the rib height and rib spacing on the bond strength was found. In addition, large rib widths resulted in lower bond strength. Contrary to previous findings, the bond strength was mostly independent of the value of relative rib area. The findings of the investigations reveal that other parameters and indicators would complement the value of relative rib area in order to describe the bond strength of reinforcing steel from coils in a more accurate manner. © 2023, Ernst und Sohn. All rights reserved.