Title:
Experimental Investigations on Reinforced Concrete Walls with Staggered Lap Splicing (Prepublished)
Author(s):
Abhishek Kumar and G Appa Rao
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
bond mechanism; flexural and shear strength; lap splice of reinforcing bars; reinforced concrete; shear walls
DOI:
10.14359/51746673
Date:
3/17/2025
Abstract:
Lap splicing of longitudinal reinforcing bars in shear walls is often encountered in practice, and the transfer of forces in lap-spliced reinforcing bars to the surrounding concrete depends on the bond strength. Buildings with shear walls during an earthquake develop plastic hinges in the shear walls, particularly where the reinforcing bars are lap-spliced. Brittle failure is commonly observed in reinforcing bar lap-spliced shear walls, which needs to be minimized by choosing the appropriate percentage of lap-spliced reinforcing bars. Therefore, it is essential to address the detailing of the lap-spliced regions of reinforced concrete (RC) shear walls. Several seismic design codes provide guidelines on lap-spliced detailing in shear walls related to its location, length of lap-splice, confinement reinforcement, and percentage of reinforcing bars to be lap-spliced. In this study, the percentage of reinforcing bars to be lap-spliced at a section is examined with staggered lap-splicing of 100, 50, and 33% of longitudinal reinforcing bars, in addition to a control RC shear wall without lap-splicing. This study tested four half-scale RC shear walls with boundary element (BE), designed as per IS 13920 and ACI 318, under quasi-static reversed cyclic loading. From the experimental study, it is observed that the staggered lap splicing of reinforcing bars nominally reduces the performance of shear walls under cyclic load in terms of the reduced flexural strength, deformation capacity, energy dissipation, and ductility of the shear walls compared to the control shear wall without lap splicing. It is also observed that the unspliced reinforcing bars do not sustain the cyclic loading in staggered lap-splice after the post-peak. Current provisions of ACI 318, EC2, and IS 13920 recommend staggered lap-splice detailing in shear walls. However, from the current study, shear walls with different percentages of staggered lap splice show that the staggered lap-splice detailing in shear walls does not improve its seismic performance.