Slabless Staircase Flexural Behavior with Multi Reinforcement Configuration

Slabless staircases represent a modern architectural innovation that eliminates traditional solid stair treads. They employ a series of open or partially supported steps, often reinforced by central support structures or narrow risers. The principal concern with this type of staircase is its flexural strength, which is restricted by the constraints of the steel reinforcement specified in the design criteria. This work investigates the enhancement of RC slabless staircases through the application of unique configurations. The examination of the staircase includes the impact of both standard and high strength concrete when reinforced with a unique type of steel rebar. Seven models were meticulously developed using the ABAQUS tool and validated against experimental data from the literature. The main characteristics examined were compressive strength and the arrangement of steel reinforcement. The findings indicated a notable enhancement in the ultimate flexural strength of a slabless reinforced concrete staircase utilizing both conventional and high-strength concrete. The reconfiguration of steel bars into a triangular formation in slabless staircases led to a significant enhancement in the final load bearing capacity, exhibiting varying percentages of improvement: a 25.2% increase in cracking load when compared to traditional models, with ultimate load improvements of 4.8% to 18%, depending on the configuration. The increase of the compressice strength could enhance the ultimate load carrying capacity with ratio reaching to 109%. The deflection increased by 7.8% with altered steel bar configurations, while ductility diminished; however, energy absorption significantly increased by many times as compressive strength rose from 50 to 70 MPa.