Effect of burning on load carrying capacity of reinforced concrete columns

الملخص EN

The experimental program consisted of casting and testing of 120 column specimens were divided into two series with target compressive strength (30 and 40 MPa) and named series A and B respectively.

Each series was divided into three main groups axially concentric loaded, 30mm and 80mm eccentrically loaded.

Results indicate remarkable reduction in load carrying capacity after exposure to fire flame.

The residual load capacity was (86-87 %), (83-85 %) for concentric loaded specimens for the two series A and B respectively, while it was (88-89 %), (85-87 %) and (110-112 %), (108-110 %) for column specimens loaded at eccentricity of (30 and 80mm) respectively at fire temperature (400oC), whereas the residual load capacity at fire temperature (600oC) was (43-46 %), (39-41 %) for concentrically loaded specimens and (46-48 %, 37-43 % and (46-52%), (45-47%) for columns loaded at eccentricity of (30 and 80 mm) respectively, whereas the residual load capacity at fire temperature (750oC) was (26-29 %), (24-27 %) for concentrically loaded specimens and (28-32 %), (23-28 %) and (40-42 %), (34-38 %) for columns loaded at eccentricity of (30 and 80mm) respectively Load-deflection curves indicate deleterious response to the fire exposure.

Also, it was noticed that the maximum crack width increases with increasing fire temperature and amount of spacing between lateral steel ties.