Experimental and numerical investigation on flexural behavior of non-prestressed concrete precast bottom slab with a section steel and two ribs

This study introduces a novel non-prestressed concrete precast bottom slab with a section steel and two ribs, designated as NPBS2R. The research aimed to evaluate the effect of section steel form and steel trusses on the flexural performance of NPBS2R. A comprehensive analysis, including three-point static loading tests and numerical simulations, was conducted on five full-scale specimens. The findings reveal that all NPBS2R specimens satisfy the free support construction requirements. Compared to conventional non-prestressed precast bottom slabs with steel trusses (NPB), the NPBS2R’s cracking moment improved by 43.5–59.5%. The section steel, remaining unyielded in tests, demonstrates potential for reuse, with its form exerting minimal impact on the overall flexural stiffness of NPBS2R. The presence of steel trusses was observed to marginally enhance the flexural behavior, contributing to a 15.0% increase. The numerical study highlights that the section size of the section steel, the chord diameter of the steel truss, and the truss quantity significantly influence NPBS2R’s flexural performance. The theoretical values derived from the study closely align with the experimental and numerical outcomes, confirming the established calculation formula’s accuracy and reliability for practical engineering applications.