Esraa Kamal Jaffar,Zinah Waleed Abbas,Layth Al Jaberi1
الملخص الانجليزي
The main object of this study is to figure out the effects of the volume of fibers (Vf) on the punching shear behavior of hybrid system of flat slab that made of Lightweight Concrete (LWC) and Reactive Powder Concrete (RPC). Five flat slabs, two of them made fully of Normal Strength Concrete (NSC) (named as S1) and LWC (named as S2), and the rest three made of LWC and RPC (named as S3, S4 and S5). The variable in S3, S4 and S5 is the values of Vf which are (0.5%, 1% and 2%) respectively. The hybrid flat slabs are designed that RPC to fill the critical zone of the punching shear area, and LWC to fill the remaining area. At 28 days age of concrete, the slabs are simply supported along the all edges and single point load applied at the center of slab until the failure is happened. The experimental work indicates that S1, S2 and S3 are failed with punching shear failure. While S4 and S5 are suddenly failed in the region occupied by LWC. The results show that S2 exhibits the weaker behavior, followed by S1. S3 has the best behavior of failure among all. The load deflection curves for all tested slabs behaves first as linear relation followed by nonlinear relation up to failure. The values of of (fcu), (Pc) and (Pu) for S1 are higher than those for S2 by about (69%, 29% and 42%) respectively. While the values of the same properties for S3 are higher than those for S2 by about (622%, 128% and 142%) respectively, and about (326%, 78% and 71%) respectively than those for S1
زينة وليد عباس | zinah waleed Abass | 13622