Two-way flexural behavior of biaxial voided slab using cuboidal shape of void formers

Abstract

A biaxial voided slab is an innovative type of slab system developed recently, that has proven its excellence in terms of its structural, environmental, and economic benefits. In the present research, an experimental study was carried out to investigate the two-way flexural behavior of biaxial voided slab using the cuboidal shape of void formers. Two-way flexure test was performed over two voided slab specimens (VS-100 and VS-140) and one solid slab specimen using a new technique of sixteen-point loading. An innovative type of positioning reinforcement was used to fix the voids at their desired locations in voided slab. The ultimate load carrying capacity, deflection, flexural stiffness, and crack pattern were examined through experimental and theoretical investigations and compared the results with solid slab. Nonlinear finite element analysis was performed to validate the experimental results using ABAQUS software. Parametric study was undertaken to investigate the flexural performance of voided slab thoroughly; varying the factors like type of loading, positioning reinforcement, and grade of concrete. These investigations revealed that the voided slab with a cuboidal shape of void former exhibits classical flexural behavior which was same as that of a solid slab. Also, it was observed that yield line theory and the finite element model predicts the similar load-carrying capacity precisely enough with the experimental investigations. Parametric study reveled that prediction of ultimate load capacity of voided slab depends on type of loading, and with uniformly distributed loading predicting relatively higher load carrying capacity. Incorporating the proposed positioning reinforcement helps to improve the overall two-way flexural behavior of voided slab.