Lap Length of Steel Bars Between Novel Prefabricated Wall and Foundation Floor Structures: Full-Scale Experiment

Abstract

In the context of promoting environmentally friendly practices, prefabricated components are increasingly utilized in civil engineering design and construction. Prefabricated shear walls, in particular, have become prevalent in contemporary residential and office buildings. Following an economic analysis of the construction steps for prefabricated walls, Shanghai Hengxu Energy Conservation Company developed a novel type of prefabricated wall for use in building basements. This innovative wall consists of two thin plates joined by distributed tie pieces, with an internal steel bar cage positioned between them. The core concrete is cast in place between the plates. The wall is designed to withstand water and soil pressures from underground and connects to the basement floor through overlapping steel bars. The effectiveness of the wall's integration with the foundation floor depends on the lap length of the steel bars, a critical factor in structural design and construction. To optimize the lap length, three full-scale specimens were tested, differentiated by varying steel bar lap lengths: 0.8 lae, 1.0 lae, and 1.2 lae, where lae represents the basic anchorage length. The specimens were subjected to horizontal loading to assess failure modes, crack propagation, load-displacement behaviors, and stress-strain responses of the reinforcements. The experimental results revealed that increasing the lap length of the steel bars beyond 0.8 lae does not significantly enhance the bearing capacity or deformation potential of the specimens.