A. A. Mahdi - Civil Engineering Department, College of Engineering, University of Diyala, Diyala, Iraq
M. A. Ismael - Civil Engineering Department, College of Engineering, University of Diyala, Diyala, Iraq

Reinforced concrete hollow-core slab (HCS) is a new type of lightweight slabs in which the longitudinal voids provide the ability to reduce the concrete amount. Reducing the concrete amount causes a reduction of the dead loads which consequently leads to cost-saving, fast construction, and getting long-span. The experimental program includes constructing and testing slab species with dimensions ۱۷۰۰×۴۳۵×۱۲۵mm to investigate the effect of eliminating concrete ratio by changing the size of the longitudinal void and the number of longitudinal voids on the performance of HCS. The experimental results showed that elimination of the concrete with percentages ۱۰.۸۳, ۱۷.۲۰ and ۲۴.۳۷% from the hollow-core high strength slabs using three longitudinal voids of diameters ۵۰, ۶۳, and ۷۵mm, respectively, resulted in saving the ultimate strength by ۹۰.۰۶, ۸۷.۸۴ and ۸۵.۰۷%, and increasing the ultimate deflection by ۵.۴۸, ۱۰.۸۰ and ۱۷.۴۴%. While, elimination of the concrete with percentages ۱۶.۲۵, ۲۴.۳۷ and ۳۲.۵۰% from the hollow-core high strength slabs using two, three, and four longitudinal voids of ۷۵mm diameter resulted in saving the ultimate strength with percentages ۸۹.۲۹, ۸۵.۰۷ and ۸۰.۶۱%, and increasing the ultimate deflection with percentages ۷.۵۷, ۱۷.۴۴ and ۲۲.۸۱% respectively when compared with the reference solid slab.

Hollow-core Slab, High strength, reinforced concrete, Self-Compacting Concrete