Title:
Development of Design Recommendations for Hooked Bar Lap Splices
Author(s):
Zack Coleman
Publication:
Web Session
Volume:
ws_S24_ZacharyColeman.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
3/24/2024
Abstract:
Hooked bar lap splices are used by over 50% of state departments of transportation and have been investigated as connection details in precast concrete moment frames. The chief advantage of hooked bars over straight bars are that the former allow for shorter splice lengths, reducing required joint widths and thereby improving speed of construction. Since hooked bar lap splices are addressed neither in the ACI 318 or AASHTO LRFD codes, design of such splices is largely speculative. To address this knowledge gap, a substantial experimental program was undertaken at Virginia Tech to develop design equations and accompanying provisions for the anchorage strength of hooked bar lap splices. Fifty-eight large-scale beam specimens containing hooked bar lap splices were tested under static loading to investigate the behavior and strength of hooked bar lap splices (Fig. 1a). The experimental results were complemented with nonlinear finite element analyses of the beams to further understand the flow of forces in such details (Fig. 1b). The ACI and AASHTO hooked bar development length equations were found to be deficient in predicting the strength of such hooked splices (Fig. 1c). Thus, the experimental and numerical results were used to develop a first-of-its-kind equation for the minimum required splice length with accompanying code provisions (Fig. 1d). The results of this research provide practitioners guidance for designing hooked bar lap splices and researchers knowledge regarding the mechanisms of force transfer in lapped bars with end anchorages.