| dc.description.abstract | The residential building market has long been dominated by concrete floor systems due to their shallow depth, which allows for more floors in multi-story buildings. However, hot-rolled asymmetric I-beams, or A-shapes, are a path forward to enable structural steel into the residential market. The wider bottom flange allows for their use in shallow-depth steel-concrete composite floor systems since the bottom flange can support precast concrete panels. Overall, this type of floor system is shallower than traditional steel-concrete composite floor systems and faster to construct.
This research study involved the design and experimental testing of a shallow-depth steel-concrete floor system to further the knowledge of A-shapes in such systems. This information will eventually lead to standardized A-shapes. The floor system concept consists of A-shapes, precast hollow-core concrete panels, and a cast-in-place concrete slab. The testing involved taking measurements during construction, which included the placement of the panels and concrete pour, service loading, and loading of the system to failure.
The major unknown parameters included the system's constructability, the system's stability during construction, how well the system would perform under live load, and the level of composite action.
This experiment revealed the system was constructed easily and quickly and remained stable during construction. The system performed well under service live load (100 psf), experiencing deflections equivalent to L/3000. The system failed due to the bond breaking between the concrete and steel, going non-composite after experiencing partially composite behavior. This occurred at an actuator load equivalent to 500 psf, or five times the service live load. All of this indicates the floor system proposed in this test is a legitimate path forward to faster construction and shallower floor systems for use in steel residential floor system design. This validates the need for the research and development of standardized A-shapes in the United States. | |
