EXPERIMENTAL & NUMERICAL INVESTIGATION OF LAP-SPLICED R/C COLUMNS UNDER THREE POINT BENDING & AXIAL COMPRESSION

Abstract

There is a valuable research work around the strength capacity of lap spliced rebars in columns specifically in accordance with bond-slip behavior or column’s seismic response. Nonetheless, lap splicing of rebars with anchored ends under combined bending and compressive loads has not yet been fully explored with due consideration of its components. It is imperative to investigate a column’s behavior under bending for different levels of axial load ratio and with different reinforcing configurations employing either plain or ribbed steel bars. This paper comparatively demonstrates the results of experimental and non-linear numerical simulations pertaining to the effect of splice strength and anchoring on the compression lap splicing of rebars in concrete column. The experimental specimens are composed by prototype-scale square columns with dense or sparse stirrups, measuring 250x250 mm and 2000 mm in length, while the steel reinforcement includes a lap splice length of 400mm. Some of the tested specimens were reinforced with plain spliced bars with anchored ends; while others included ribbed spliced bars with free ends. All the specimens were tested under simultaneous bending and constant concentric, axial loading of ν =0.1. Finally, the investigation results outline the influence of lap splice to the structural integrity of the column as a part of a composite system and generally evaluate the resistance of the lap splices in a plastic joint area, under parametric analysis.