الفهرس 
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Abstract
The uses of reinforced concrete flat slabs systems are becoming popular in most of
construction project. Flat slab systems are suitable for most floor cases and usage.
The flexibility of flat slab construction can lead to high economy and also allow
more freedom for architectural purposes.
The experimental work presented in this study was undertaken to investigate the
ultimate punching shear response of reinforced concrete slabs. The experimental
program consisted of twelve slab specimens of square shape, each with a column
stub at its center. The test specimens were intended to simulate a half scale interiorslab-
column connection. The tested slabs were divided into four series according to
test parameters. The parameters investigated include ratio of flexural reinforcement
in compression and tension, amount of shear reinforcement and arrangement of shear
reinforcement. All specimens were tested as simply supported slabs under one point
static loading. The load was applied as a static load.
A comparison established between the experimental and the analytical results
obtained from applying the punching shear strength formulae given in design codes,
and non-linear finite element analysis; NLFEA flowed by parametric study to
investigate the influence of concrete strength. A total of four building codes were
examined with regard to their provisions concerning the punching shear. ANSYS
10.0 software package was used for non-linear analysis.
Based on this investigation, the following conclusions can be drawn. Flexural
reinforcement ratio especially in tension side had a noticeable effect on the mode of
failure and ultimate punching capacity of flat slabs. Flexural reinforcement ratio and
shear reinforcement had insignificant effect on the cracking loads of the tested
specimens, with a noticeable effect on the cracking patterns and ductility. The
ultimate load of the tested specimens increased as the tensile reinforcement
increased. The enhancement in the ultimate loads due to increasing tensile
x
reinforcement ratio was ranging between 26.0% and 42.0%. Slightly enhancement
(up to 12%) in ultimate loads was observed as a result of increasing compressive
steel ratio. Provision of shear reinforcement was shown to increase the perimeter of
the failure. Specimens with shear reinforcement failed at larger perimeters than slabs
without shear reinforcement. The ultimate loads were increased with the addition of
single leg stirrups as shear reinforcement particularly in case of radial arrangement of
shear reinforcement. An increase in the ultimate load ranging between 6% and 27%
was recorded for specimens with shear reinforcement compared to test slabs without
shear reinforcement. To the range of the test parameters investigated, the application
of non-linear finite element analysis using ANSYS 10.0 package yielded satisfactory
load-carrying capacities and load-deflection responses with acceptable cracking
loads. Codes comparison indicates a significant variation in the punching shear
predictions from code to another. The ECCS shows the most conservative prediction
for punching shear capacity specially in case of using shear reinforcement as the
code provisions neglect the effect of shear reinforcement. The mean predicted-toexperimental
ultimate load is shown to be 0.7. The predictions following the ACI
and CSA are closet to the experimental results. The mean predicted-to-experimental
ultimate load is shown to be 0.8 and 0.96 for ACI and CSA, respectively. The BS
provisions for punching shear analysis were shown to be overestimated in some
cases, where the mean predicted-to-experimental ultimate load is shown to be 1.19.
The proposed equations for punching shear capacity of flat slab resulted in more
accurate results compared with the codes predictions.