Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Punching shear

Punching Shear Behavior of Fibrous Self -Compacting Concrete Flat Slabs

Mutaz Kadhim Medhlom

Engineering and Technology Journal, 2014, Volume 32, Issue 12, Pages 2874-2890

This research is devoted to study the mechanical properties of fibrous self-compacting concrete (FSCC) as materials as well as studying the punching shear behavior of FSCC slabs. The experimental program includes investigating the effect of steel fiber volumetric ratio (Vf) and absence of limestone powder on some important mechanical properties of FSCC such as compressive strength, modulus of elasticity, splitting tensile strength and modulus of rupture. Additional experimental tests are also conducted to study the effect of Vf, steel reinforcement ratio (ρ) and slab thickness on the punching shear behavior (in terms of load-deflection response and ultimate failure load),and the failure characteristics of the punching shear (in terms of observation of failure, shape of the failure zone, size of the failure zone, failure angles, critical section perimeters and ultimate punching shear stress ) of simply supported reinforced FSCC slabs having dimensions of 1000×1000× 50 or 70 mm under concentrated load at the center of the slab.

Effect of Elevated Temperature on Punching Shear of Regular and Irregular Shaped Self-Compacted Concrete Slabs

Luma Fadhil H

Engineering and Technology Journal, 2010, Volume 28, Issue 19, Pages 5893-5906

The exposure of reinforced concrete slabs to high temperature causes changes
in their structural behavior.
This work aims to study the post-heating behavior of self compacted concrete
(SCC) regular (square) and irregular (trapezoidal) shaped flat plates and assessing
the residual punching shear strength of these slabs.
Twenty four reduced scale reinforced concrete slab specimens divided into
two main groups (square and trapezoidal slabs), each of which consists of twelve
slab identical in size and shape but different in concrete compressive strength
(30,50,70) MPa. These specimens are subjected to different temperature levels
(100, 300, 500) 0C and still heated in that temperature level for one hour using an
electric furnace and the results are compared with specimens tested at room
temperature 25 0C.
The effect of specimen shape, heating level, concrete compressive strength on
the punching shear resistance of slabs are discussed in details.
Results indicate that the reduction in punching shear strength is ranged between
(0 and 16) %, for square slab, at maximum temperature exposure (500) 0C, while
this rate is ranged between (6.3 and 40.4) % for trapezoidal slabs. This indicates
that the punching shear resistance of regular shaped slabs is higher than that of
irregular shaped slabs.