Experimental study on flexural performance of iron tailings concrete beams after fire
In order to study the effect of replacing natural sand with iron tailings sand on the flexural performance of concrete beams after fire,static load tests were carried out on three concrete beams exposed to fire for 45 min and three concrete beamsnon-exposed to fire.The temperature distribution of concrete and reinforcement in the beam during fire,the mid span deflection of the beam,the load deflection curve of standard post fire static load test,the residual bending capacity,and the failure mode were compared.The plane section assumption was verified,and the influences of all iron tailings sand replacing natural sandand thestrength of different iron tailings sand concreteon the bending resistance of reinforced concrete beams after fire were analyzed.The results show that there is no significant difference in the temperature fieldof concrete and steel bars and mid span deflectionbetween iron tailings sand concrete beam and natural sand concrete beam under fire,and both meet the plane section assumption after 45 minutes of fire.The residual flexural capacity of iron tailings sand concrete beams after fire is not significantly different from that of natural sand concrete beams,but the mid-span deflection increases significantly during failure.The strength C30 or C40 of concrete with different iron tailings has little effect on the flexural capacity of beams after fire.
iron tailings sand concretesimple supported beamafter fireflexural behaviorplane section assump-tion
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