Flexural Behavior of Reinforced Concrete Partially

Abstract

This research deals with the flexural behavior of partially end restrained slabs subjected to burning by fire flame. The investigation is based on casting and testing 16 reduced scale (600×600×40mm) reinforced concrete slab specimens. Two concretemixes with design 28 days compressive strengths of (30 and 38 MPa) were adopted.Two steel ratios of (0.005, 0.009) were used. The specimens were exposed to fire flametemperature levels of (400,500 and 600211°C) at the lower surface of the slab specimenswith exposure duration of one hour, then after 24 hours; they were tested in flexure tofailure under uniformly distributed load while they are partially edge restrained againstlateral and rotational movements. It was found from the results that the values of ultimate load capacity, decreasedfor all specimens after exposing to fire flame. The residual ultimate load capacity forspecimens burnt at temperatures of (400 and 500°C) was higher than that for specimensburnt at 600°C. At temperature around 600°C and for steel ratios of (0.005 and 0.009),the percentages of residual ultimate load ranged between (85 and 87%) respectively.The residual compressive strength at 600°C was about (63 %). However the residualmodulus of rupture was in the range of (47 and 51 %) and the residual modulus ofelasticity ranged between (29 and 26%) at 600ºC.