Research of stressed-state stiffened hollow strengthened concrete slabs in cracked condition

In fact, while making engineering calculations, hollow slabs are presented as T-shaped and I-beams. In this case, the web face of a beam decreases according to the dimensions of cavity pockets inside a slab. The conventional theory of calculating building constructions with breaking stress involves the calculation of such hollow slabs focused on the beam theory. In this paper, the authors observe the stress condition of hollow slabs at failure. Numerical studies are carried out for slabs re-enforced in several ways. The authors perform calculations in nonlinear formulation with gradually increasing stress before the samples were distorted. The researchers compare the stress condition in the slabs with normal cross-sections to the stress condition in the similar I-beam slabs. The aim of the study is to outline the way the cross section shape representation influences the results of direct stress in section and the cracking moments from the bending moment in the center of the slab span. The scholars take into account various methods of reinforcing hollow-core slabs. The paper emphasizes that the moment of crack propagation for hollow slabs in a normal shape comes later than for I-beam slabs. (paper)