Prof. Rui Pang
Henan University of Technology
China
Abstract Title: Experimental and Analytical Study on Vertical Bearing Behavior of Discretely Connected Precast Concrete Floors with Four Sides Simply Supported
Biography:
Prof. Rui Pang received his Ph.D. from Southeast University in January 2012. He is now the deputy director of the science and Technology Department of Henan University of Technology. His research focuses on prefabricated concrete structures, steel structures, super-high-rise buildings, and new warehouse structures. He has led 3 National Natural Science Foundation projects, 3 provincial-level projects, and over 10 industrial research projects. He has published more than 80 papers, including over 40 SCI/EI-indexed articles, and holds over 10 national invention patents. He has also edited and co-authored several national standards and textbooks.
Research Interest:
Floor is a horizontal load–bearing member in a building designed to bear and transmit gravity and lateral loads to the vertical load–bearing members. In order to transmit internal forces generated by vertical and horizontal loads through its slab joint connections, a creative discretely connected precast concrete floor (DCPCF) was proposed. The slab joint connections utilize hybrid connectors containing hairpin connectors (HPC) and cover-plate connectors (CPC). The validity of this design concept was confirmed through Previous studies. However, the mechanical properties of DCPCF are not very clear. In order to further investigate the load transfer mechanism and vertical bearing capacity of DCPCF, and the influence of factors such as the number of connectors, the number of PC slabs, and the type of connectors, a two-stage research program was conducted. The first step involved assessing the vertical bearing capacity of DCPCF in the OSL direction under the condition of simple support at two ends. Six DCPCF specimens and two cast-in-situ (CISS) specimens were tested and analyzed. During this stage, the influence of parameters such as the number of slab joints and connectors on the force transfer performance of DCPCF in the OSL direction was analyzed, providing a basis for establishing the bending stiffness of DCPCF in the OSL direction. The second step focused on assessing the vertical bearing capacity of DCPCF under the condition of simple support at four sides. Two DCPCF specimens and one CISS specimen were tested and analyzed. During this stage, the primary focus was on the two-way load transfer mechanism and vertical bearing capacity of DCPCF, with the main goal being to establish the calculation method for DCPCF’s bearing capacity and deformation under four-sided support conditions. This paper primarily presents the results of the second stage of research. The results showed that DCPCF had high bending stiffness and bearing capacity, which the same as those of CISS basically. The discrete slab connectors of DCPCF specimens exhibited good force transmission performance throughout the loading process, and no obvious local failures were observed. The flexural deformation shape, failure mode, and crack distribution of DCPCF were similar to those of CISS, which indicating that the slab joint connections can effectively transfer internal force in the orthogonal slab laying direction (OSL direction), and giving DCPCF the characteristics of a typical two-way slab floor. In addition, the initial stiffness and deformation of DCPCF specimens was slightly smaller than that of the CISS specimen, which shown that DCPCF had better deformation recovery ability. Compared with the CISS specimen, DCPCF specimens exhibited no obvious plastic stage and entered the nonlinear working stage earlier. A problem worthy to be pointed out was that simplified formulas for the equivalent bending stiffness of DCPCF in the OSL direction were derived by using the conjugate beam method. Furthermore, the vertical bearing capacity and deflection equations of DCPCF with simply supported on four sides under a uniform distributed load were derived based on the small deflection theory of orthotropic elastic thin slabs, and the theoretical calculation values were in good agreement with test values.