Experimental study on precast HPC slab-steel composite floor with high-strength grout shear key under uniform stacking loading

Mirmoghtadaei, Sayed Parsa; Mostofinejad, Davood; Eftekhar, Mohammad Reza

doi:10.22065/jsce.2025.547780.3820

Experimental study on precast HPC slab-steel composite floor with high-strength grout shear key under uniform stacking loading

Document Type : Original Article

Authors

Sayed Parsa Mirmoghtadaei ¹

Davood Mostofinejad ²

Mohammad Reza Eftekhar ³

¹ Master of Science, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

² Professor, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

³ Associate Professor, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

10.22065/jsce.2025.547780.3820

Abstract

In steel structures, selecting a floor system that lowers the structure’s self-weight, reduces labor-intensive tasks, and accelerates construction is crucial. Conventional steel-concrete composite floors are among the most commonly used composite floor systems, but the need for steel decking, temporary formwork, and in-situ concreting stops them from being ideal. This study introduces an innovative steel-concrete composite floor system, comprising precast high-performance concrete (HPC) slabs, steel beams with pre-welded shear studs, and high-strength expansive grout as a shear key, in both longitudinal and transverse directions. This composite floor system eliminates the above-mentioned problems of conventional steel-concrete composite floors. Thin HPC precast slabs lower the overall structural weight and seismic forces, facilitate the use of slender structural members, and accelerate construction. For more accurate evaluation of the composite action in the proposed floor system, a composite specimen was subjected to uniform stacking loading, which, unlike most previous research studies, takes advantage of having two spans, multiple precast slabs, and full-scale size. After bearing 15.2 kN/m² of uniform stacking load, the composite specimen not only did not fail, but also did not experience plastic deformation. The maximum deflection of the specimen’s middle beam was 6.7% less than that of an equal-sized in-situ steel-concrete composite floor. According to AISC 360-22 and ASCE/SEI 7-22, the composite specimen satisfies the serviceability deflection limit and minimum design loads for most residential and office uses. The proposed composite floor offers a reliable and efficient solution that expedites flooring in steel structures.

Keywords

Precast concrete slab

HPC

Steel-concrete composite floor

High-strength grout

Uniform loading

Subjects

Innovation in Design and Construction

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