Slabless Staircase Flexural Behavior with Multi Reinforcement Configuration

Abstract

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 highstrength 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 loadbearing 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.