高强混凝土简支梁高温下抗剪性能

Shear Behavior of High-strength Concrete Simply Supported Beams at High Temperature

为研究高强混凝土简支梁高温下的抗剪性能,基于ABAQUS有限元分析软件建立了强度为C80的7根有腹筋梁和3根无腹筋梁,采用顺序热-力耦合的作用方式,对高温下高强简支梁的抗剪性能进行模拟,分析了有无腹筋、不同的箍筋配筋率和纵筋配筋率对梁高温下抗剪性能的影响。结果表明:增加箍筋和纵筋配筋率可以提升高强混凝土梁的耐火极限,有腹筋梁耐火极限的提升幅度随纵筋配筋率的增加而降低;相同模拟条件下,无腹筋梁的截面温度分布低于有腹筋梁,使无腹筋梁的耐火极限略高于有腹筋梁。

In order to study the shear performance of high-strength concrete simply supported beams at high temperature,7 beams with web reinforcement and 3 beams without web reinforcement with strength of C80 were established based on ABAQUS.The shear performance of high-strength simply supported beams at high temperature was simulated by thermodynamic coupling.The effects of web reinforcement,different stirrup ratio and longitudinal reinforcement ratio on the shear performance of beams at high temperature were analyzed.The results show that increasing the reinforcement ratio of stirrups and longitudinal reinforcement can improve the fire resistance of high-strength concrete beams,the increase of the fire resistance limit of the beams with web reinforcement decreases with the increase of the longitudinal reinforcement ratio;Under the same simulation conditions,the section temperature field of the beam without web reinforcement is lower than that of the beam with web reinforcement,so that the fire resistance limit of the beam without web reinforcement is slightly higher than that of the beam with web reinforcement.