HRB500级钢筋混凝土构件受力性能的试验研究

【作者】 张艇；

【导师】 刘立新； 徐有邻；

【作者基本信息】 郑州大学 ， 结构工程， 2004， 硕士

【摘要】 HRB500级钢筋抗拉强度标准值为500MPa，是一种强度高，延性好的新型钢筋，在国外已得到广泛应用。而我国《混凝土结构设计规范》GB50010-2002中尚未列入，为尽快实现与国际接轨，在我国工程领域推广这种新型钢筋，需对HRB500级钢筋混凝土构件主要受力性能进行试验研究。 HRB500级钢筋混凝土构件的受弯性能试验研究表明，HRB500级钢筋混凝土构件受弯性能与普通钢筋混凝土构件相同。受弯构件可按现行《混凝土结构设计规范》GB50010-2002中受弯构件的正截面的承载力计算公式计算，无论取f_y=420MPa或f_y=400MPa，采用HRB500级钢筋混凝土构件均有足够的安全储备。在正常使用极限状态下，HRB500级钢筋混凝土受弯构件的挠度、裂缝宽度均可按现行《混凝土结构设计规范》GB50010-2002中规定公式计算，但应进行适当修正。对于挠度值应乘以扩大系数1.25，对于最大裂缝宽度计算值应乘以折减系数0.9。由于HRB500级钢筋在正常使用极限状态下的工作应力σ_sk较大，建议在设计中对HRB500级钢筋混凝土受弯构件进行裂缝宽度验算。 HRB500级钢筋混凝土构件受剪性能试验研究表明，HRB500级钢筋混凝土构件的受剪性能与普通钢筋混凝土构件相同。受剪承载力可按现行《混凝土结构设计规范》GB50010-2002中规定的斜截面承载力公式计算。由于HRB500级钢筋强度较高，作为箍筋使用时应力未能得到充分发挥，破坏时大部分箍筋未能达到400MPa。建议箍筋屈服强度设计值取f_yv=380MPa或f_yv=360MPa。 连续梁的受力性能试验研究表明，由于HRB500级钢筋有较好的延性，塑性铰有足够的转动能力，在超静定结构中可形成破坏机构，实现完全的塑性内力重分布，可用于按考虑塑性内力重分布设计的结构。更多还原

【Abstract】 The standard value of HRB500 steel bar’s tensile strength is 5000MPa. It is a new type steel bar which has many merits, such as hi-strength and strong ductility. This kind of steel bar has been used prevalently in foreign countries. But it hasn’t been taken in by new Code for design of concrete structures (GB500’10-2002). In order to take the internationalization into reality as soon as possible and popularize this new kind of steel bar in engineering area of our country, the experiment researches should be done on the main characteristic of HRB500 reinforced flexural members.The experiment research shows that the performance of flexural member reinforced with HRB500 steel bar is the same as that of the common reinforced concrete members. It’s bearing capacity of flexure member can be calculated by the formula of cross-section in the Code for design of concrete structure (GB50010-2002). The result shows that: whether =fy420MPa orfy=400MPa, the HRB500 steel bar member is safe enough.The research of HRB500 reinforced flexural members shows that the flexural members’ width of cracks and deflection under limit state of serviceability can be calculated by formulas in existing Code for design of concrete structures (GB50010-2002),while they should be amended properly.As for the value of deflection, it should be enlarged by a coefficient 1.25. Similarly, the max-width of cracks should be discounted by a coefficient 0.9. Because the HRB500 steel bar’s working stress (under the limit of serviceability ) is larger than other bars in existence, we suggest that a checking computation to the width of cracks of the flexural members should be given.The research shows that the performance of shear member reinforced with HRB500 steel bar is the same as the common reinforced concrete members. According to the Code for design of concrete structure (GB50010-2002), the bearing capacity of HRB500 steel bar under shear can be calculated by the formula of bearing capacity in oblique cross-section. Because of its high strength, the HRB500 steel bar cannot reach its max strength, and most of strengths of steel bars are no more than 400Mpa when the member destroyed. So I proposefyv=380Mpaor 360 Mpa.The research shows that HRB500 reinforced continuous beam have enough ductility, "plastic hinge" has full rotation capacity. Continuous beam can implement the plastic internalforce redistribution. This can be take into account when design HRB500 bar reinforced construct.更多还原