scholarly journals 2045) Rigidity in the horizontal direction of the Precast Concrete Floor Slabs(Structure)

1959 ◽  
Vol 63.1 (0) ◽  
pp. 413-416
Author(s):  
Yoshisa Gyoten ◽  
Kazuhiko Takeyama
2016 ◽  
Vol 20 (5) ◽  
pp. 759-771 ◽  
Author(s):  
Feng Lin ◽  
Xiuming Yang ◽  
Keyu Li ◽  
Xianglin Gu ◽  
Xiang Li

Investigations on buildings severely damaged due to earthquakes or explosions have indicated that unreinforced masonry buildings with simply supported precast concrete floor slabs exhibit deficiencies in resistance to progressive collapse, compared to unreinforced masonry buildings with continuous cast in situ concrete floor slabs. The collapse mechanisms observed in the two types of unreinforced masonry buildings are closely related to wall–slab joint failure. The purpose of this study is to investigate the failure behavior of wall–slab joints and the effect on the collapse of the two types of unreinforced masonry buildings. Six wall–slab joint specimens and eight grooved wall specimens, induced by partial failure of wall–slab joints, were tested under monotonic vertical and horizontal loading. Numerical models were then developed, verified, and used to perform a parametric study. It was found that the wall–slab joints failed in various modes, that is, slab failure, wall failure, and slab pullout failure. The grooved wall could fail in bending or in compression. Analyses indicated that the collapse of unreinforced masonry buildings with simply supported precast concrete floor slabs develops in both vertical and horizontal directions. However, the collapse of unreinforced masonry buildings with continuous cast in situ concrete floor slabs is prone to develop only in the vertical direction, resulting in improved progressive collapse resistance.


PCI Journal ◽  
2019 ◽  
Vol 64 (4) ◽  
Author(s):  
George Morcous ◽  
Eliya Henin ◽  
Maher K. Tadros

Author(s):  
Lidiya Kosheleva ◽  
◽  
Sergey Mijusov ◽  
Sergey Kletenkov ◽  
Daniil Ryazantsev ◽  
...  

2017 ◽  
Vol 76 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Jan Ekr ◽  
Eva Caldova ◽  
Petr Vymlatil ◽  
Frantisek Wald ◽  
Anna Kuklikova

Author(s):  
Yevhen Dmytrenko

Traditional methods of calculation of beam constructions of floors and coverings of industrial buildings assume their consideration when calculating separately from the frame structures, in particular, reinforced concrete slabs, without taking into account their joint work, which leads to a significant margin of safety. Today in Ukraine there is a significant number of industrial buildings and structures that need strengthening and reconstruction. In this regard, of particular importance are studies of the actual load-bearing capacity of the frames of single-storey and multi-storey industrial buildings, and both in the reconstruction and in new construction, the results of which will significantly reduce costs and more rationally design structures. At the same time, one of the most relevant areas is the study of the joint work of metal load-bearing structures with prefabricated reinforced concrete structures of rigid disks of coatings and floors in their calculation.           Moreover, in the national building codes, as well as in the educational and methodological literature, the calculation methods of taking into account the joint work of such constructions are not fully covered. The purpose of this work is to estimate the reduction of mass of the metal beam structure in its calculation in bending, taking into account the joint work with the rigid disk of the floor consist of precast concrete. As part of the study, the calculation of the floor beam according to the traditional calculation scheme - without taking into account the joint work with the floor slab, the calculation of its cross-section taking into account the joint work with floor slabs and experimental numerical study of the floor by the finite element method. Modeling of the floor fragment was performed in the software packages "SCAD Office" and "LIRA CAD 2019". Numerical research is aimed at verifying the feasibility of using the calculation methodology of DBN B.2.6-98-2009 to determine the effective width of the shelf when calculating the T-sections for prefabricated reinforced concrete slabs, which are included in the joint work with the floor beams. A comparative analysis of the obtained cross-section of the beam with the beam which was previously calculated by the traditional method of calculation  in stresses in the most dangerous cross section and the total mass of the beams. According to the results of the analysis, the correctness of the application of the above normative method for determining the effective width of the shelf of T-bending reinforced concrete elements was confirmed.


Author(s):  
Noboru YUASA ◽  
Yoshio KASAI ◽  
Isamu MATSUI ◽  
Yoshio HENMI ◽  
Hirokazu SATOH

2019 ◽  
Vol 968 ◽  
pp. 330-341
Author(s):  
Talyat Azizov ◽  
Wit Derkowski ◽  
Nadzieja Jurkowska

The paper discusses the principles of precast concrete hollow-core slabs taking into account their spatial work. It is shown that consideration of spatial work makes it possible to determine the forces in individual floor slabs significantly more precise. The fact that strain redistribution between precast floor slabs depends on slabs’ bending and torsional stiffness is shown. The research has been mostly devoted to determination of the bending stiffness with regard to formation of cracks and the change in torsional stiffness, especially considering the presence of normal cracks, which is still unstudied. This paper presents the technique for determining the torsional stiffness of hollow-core slabs with normal cracks. In order to determine the components included in the resolving system of equations, it is proposed to use an approximation method based on the processing of numerical data using spatial finite elements.


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