HRB500/HRB600钢筋作纵筋的混凝土连续梁弯矩调幅试验研究

HRB500 and HRB600 steel bars have been adoptedby 'Code for design of concrete structures' (GB50010-2010)and'Steel for the reinforcement of concrete-Part 2: Hot rolled ribbed bars'(GB/T 1499. 2-2018). In order to investigate the moment redistribution in continuous reinforced concrete beams with HRB500 and HRB600 steel bars as tensile longitudinal bars, 24 two-span continuous beams were tested in this study. The test results showed that the moment redistributionoccurred not only after the formation of plastic hinge but in the process from plastic development of the tensile concrete to the formation of the plastic hinge. The moment redistribution was investigated in two stages, namely, before and after the appearance of the plastic hinge. The first-stage moment redistribution(β_I) was between15.28%~24.21%and the second-stage moment redistribution (β_II) was between 6.91%~30.3%. It was found that the increase in the yield strength of tensile longitudinal steel bars led to an increase in β_I but a decrease inβ_II. Moreover, β_I and β_II increased with the increase in the width of the mid-support and the decrease in the relative depth of the compressive zone. Formulasforthe moment redistribution of two stages considering the effects of the key factors were proposed based on the test results.