火灾后配筋混凝土梁受力性能试验与分析

为研究火灾后配筋混凝土结构的受力性能,对3根有粘结预应力混凝土简支梁和2根钢筋混凝土简支梁进行了抗火试验和火灾后的常温静力试验,基于试验结果,提出了火灾后配筋混凝土梁正截面承载力计算公式、裂缝宽度计算公式和刚度计算公式.从5根试验梁中取出20根普通钢筋和9根预应力钢丝进行单向拉伸力学试验,获得了火灾后HPB235级钢筋、HRB335级钢筋、1670级低松弛高强钢丝的力学性能.

Experiment and analysis on mechanical properties of reinforced concrete beam after fire

To study the mechanical properties of reinforced concrete structure after fire,experiments on fire resistance performances of 3 bonded prestressed concrete simple-supported beams and 2 reinforced concrete simple-supported beams and static load tests at normal temperature on these 5 simple-supported beams after fire were carried out. Based on test results of the 5 beams after fire,calculation formulas of the flexural bearing capacity,the crack width and the stiffness for prestressed concrete beams and reinforced concrete beams after fire were presented.Tensile tests on 20 ordinary reinforcements and 9 prestressed steel wires taken from the 5 beams were performed,and mechanical properties of HPB 235,HRB335 and 1670 grade of low relaxation and high strength steel wire after fire were obtained.