Browsing by Author "Karasin, Abdulhalim"

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The Effect of Voids on Flexural Capacity of Reinforced Concrete Slabs
(Budapest Univ Technology Economics, 2023) Kipcak, Firat; Erdil, Baris; Tapan, Mucip; Karasin, Abdulhalim
The voided reinforced concrete slab system is mainly produced with polyester foam placed mostly at the bottom of the slab. The aim of the voids is to reduce the weight of the slab. In this paper behavior of the voided reinforced concrete slabs in which voids placed at the mid-height of the slab cross-section, is examined analytically. A series of models were created to come up with a lightweight slab. Two distinct slab models were analyzed using the ABAQUS software. In the first group, slabs had three layers, in which bottom and top layers were of solid reinforced concrete, but the mid layer was of voided unreinforced concrete. In the second layer, in order to increase the contact between top and bottom layers of the slab, crossties were utilized, and the mid layer was reinforced accordingly. Since all the layers were 5 cm thick, the total thickness of the slabs were 15 cm. Slabs were 100 cm wide and 200 cm long. They were simulated the three-point bending test. Concrete damaged plasticity material model (CDPM) for concrete and elastoplastic material model for steel was selected. From the results it was found that moment capacity decreased with the increase in the volume of the voids. There was a sudden decrease in strength after reaching the yield strength in voided slab without a crosstie. In addition, crossties enabled the reduction of the weight of the slabs without significant decrease in moment capacity.
Investigation of Flexural Behavior of Voided and Crosstie Reinforced Slabs
(Wiley, 2025) Kipcak, Firat; Tapan, Mucip; Erdil, Baris; Karasin, Abdulhalim
Reinforced concrete slabs constitute a significant portion of the building weight. One of the methods developed to reduce the slab weight is the voided slab system. In this system, voids are formed with materials such as plastic or foam. In this study, voided slabs with concrete connections, which are rarely found in the literature, were investigated. Because there is no sufficient study regarding the bending capacity and behavior of voided slabs, 11 slabs with varying void ratios and crosstie reinforcement were tested to fill this gap. In this context, three solid slabs without voids and eight slabs with different void ratios were produced. Polystyrene foam was used to create three equal layers. The top and bottom layers are reinforced concrete, and the middle layer consists of square concrete connections and polystyrene foam, which has not been studied yet. The slabs were divided into two groups: the first group specimens had no crossties, whereas the second group had varying crossties. In this context, it was tried to determine the optimum weight and performance of the slab. A uniformly distributed load was applied using the three-point bending method. According to the results, the slab weakened with the use of polystyrene foams, and the ultimate load capacity decreased accordingly. The stiffness, ductility, toughness, and load capacity of solid slabs were found to be higher than those of voided slabs. When the void ratio was 20%, the failure mode changed from flexure to shear. By using crosstie reinforcement, shear failure was prevented, and ductile behavior was increased. Finally, the load capacity of the slabs was compared with ACI318-19 and other studies, and a new equation was proposed.