Experimental investigations of precast concrete column with spliced connections based on ultrahigh-performance fiber-reinforced concrete

When compared with normal concrete, ultrahigh-performance fiber-reinforced concrete (UHPFRC) could signally enhance the bond with reinforcing bars. Accordingly, incorporating UHPFRC to connect precast concrete columns allows smaller bar splice lengths and provides ease of construction. In this article, a two-stage research program was presented. First, the behavior of double-row spliced rebars in UHPFRC was tested under direct tension, and the bars adopted internal strain measurement to characterize the bond stress distribution along the splice length. The failure of specimens was governed by UHPFRC splitting, and the bond stress of spliced rebars in UHPFRC presented a two-local peaks profile. Second, the hysteretic performance of precast concrete columns with spliced connections based on UHPFRC was determined by full-scaled cyclic tests and numerical simulations. Precast columns with UHPFRC connections at the column base exhibited similar ductility, energy dissipation capacity, and higher bearing capacity to the monolithic concrete columns. Finally, some practical considerations and recommendations were proposed.