HRB500钢筋混凝土梁静动态受弯承载力试验研究

Static and dynamic experimental investigation on flexural bearing capacity of HRB500 reinforced concrete beam

为研究HRB500钢筋混凝土简支梁的受弯承载力,进行7组21根适筋梁的静、动态三分点弯曲加载试验,分别采用0.6%、1.0%两种配筋率,C40、C60两种强度等级的混凝土,3种加载速度,获得梁的截面应变分布曲线,以及开裂载荷、屈服载荷、极限载荷和延性比等参数。通过对比分析试验结果,认为在动态载荷作用下,平截面假定依然成立,梁的开裂载荷可提升1倍以上,屈服载荷和极限载荷有小幅提升。动态屈服载荷可采用静载时的计算方法进行计算,但需要将钢筋和混凝土的静态强度替换为动态强度。梁的延性比基本不受加载速度的影响,配筋率越高的梁延性比越低。

In order to study the flexural bearing capacity of HRB500 reinforced concrete simple supported beam, static and dynamic tests of three dividing point loading were carried out. 21 beams in 7 groups were tested under 3 different loading speeds. The reinforcement ratio was 0.6% and 1.0% respectively, and the strength grade of concrete was C40 and C60 respectively. The strain distribution in the section, cracking load, yield load, ultimate load and ductility ratio were obtained. The comparative analysis of the experiment results show that, under dynamic load, plane section assumption is also tenable, and the cracking load of beam is significantly raised more than one time. The yield load and ultimate load increased a little. The dynamic yield load can be calculated by the method derived from static load condition, but the static strength of rebar and concrete must be replaced by the dynamic strength. The ductility ratio of beam is basically not influnced by loading speed, but it is lower when the reinforcement ratio is higher.