Anchorage performance of grouted corrugated duct connection under monotonic loading: Experimental and numerical investigation

Abstract

The grouted corrugated duct connection (GCDC) has wide applications in column-to-cap beam and column-to-footing joint of precast bridges. The anchorage performance of GCDC has received more attention due to the lack of understanding. In this study, a two-phase experimental program was conducted to investigate the anchorage performance of GCDC. The pull-out tests of 40 specimens in Phase Ⅰ mainly focused on the effects of various factors on anchorage requirement of GCDC, in which factors such as anchorage length, duct-to-rebar diameter ratio were considered. Test results indicate that the failure modes of GCDC and the proposed equivalent bond stiffness are mainly governed by the anchorage length and duct-to-rebar diameter ratio. The anchorage length of 10–15 times rebar diameter and duct-to-rebar diameter ratio of 2.5–3.5 are recommended to ensure bond strength. In Phase Ⅱ, 40 design specimens were pulled out to investigate the bond-slip constitutive relationship of GCDC. The variation law of ultimate bond strength was analyzed with the variation of the anchorage length and duct-to-rebar diameter ratio. Based on experimental results, basic bond stress-slip relationship and bond stress distribution function were obtained through curve fitting, which were in good agreement with test results. Finally, the comprehensive bond-slip constitutive model incorporating location function was developed. The refined finite element model considering bond-slip constitutive relationship was established to investigate and verify the pull-out test results. Therefore, the anchorage requirement recommended can provide reference for the selection of anchorage length duct-to-rebar diameter ratio for engineering application of GCDC. Furthermore, the bond-slip constitutive model developed is the theoretical basis for finite element analysis of GCDC.