Behavior of reinforced geopolymer concrete flat slab exposed to high temperature

Abstract

In this study, fifteen 700x500 mm concrete flat slabs made of geopolymer concrete were examined under concentrated to identify the maximum punching shear resistance under the influence of various factors such as steel fiber content, slab thickness, flexural reinforcement ratio, in addition to replacing 10% of metakaolin by silica fume under the influence of temperature increasing up to 300 oC in addition to testing ninty control specimens to investigate the mechanical properties. It was observed there was a beginning to change in the structural behavior when the temperature reached 100 oC due to an increasing in the pressure by the liquid vapor, then a important drop in the capacity and behavior when reaching the temperature 300 oC. The presence of iron fibers led to a decreasing in the distance between the edge of the column and the critical section, which reduced the punching shear values. Decreasing of the maximum and cracking of the punching shear were recorded at 37% and 42%, respectively, when the temperature increased to 300 ° C.