Effect of hole diameter on ultimate bearing capacity of hollow-core slabs by finite element method

Abstract

In recent years, extensive studies have been conducted on the load bearing and main members of reinforced concrete structures such as concrete beams, columns and slabs under shear, bending and even torsion to determine the ultimate bearing capacity of the members. Despite extensive research in these areas, little research activities have been done on a type of slab called hollow-core concrete slab. Also, the effect of hollow-core hole diameter on the volume of concrete placing, weight of the slab and consequently, of the entire structure, as well as the cost of construction and finally, the ultimate bearing capacity of hollow-core slabs is a fundamental issue that seems inevitable. Considering the importance of the above-mentioned issues, this paper examines the effect of hole diameter on the ultimate bearing capacity of hollow-core slabs using the finite element method. For this purpose, at first, the hollow-core concrete slab was modeled in in ANSYS software and then, for problem validation, it was compared with the laboratory model. After validation, the parameter of hole diameter was changed and the obtained results were evaluated. It should be noted that the changes was applied on four hollow-core slab of 1.5, 4, 6 and 9 m long shown in the studies. The maximum hole diameter of the slab can be used to reduce the weight of the slab and optimize the sections. This is because the ultimate bearing capacity of the hollow-core slab does not change as the diameter of the hole is reduced. In other words, by reducing the hole diameters in hollow slabs, their ultimate bearing capacity does not increase.