Effect of elevated temperature on punching shear of regular and irregular shaped self-compacted concrete slabs

Abstract EN

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( .

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.

(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.