HRB500钢筋粘结锚固性能的试验研究

【作者】 毛达岭；

【导师】 徐有邻； 刘立新；

【作者基本信息】 郑州大学 ， 结构工程， 2004， 硕士

【摘要】 HRB500钢筋是指强度标准值为500MPa的热轧带肋钢筋，是我国通过对钢筋成分的微合金化而开发出来的一种强度高、延性好的钢筋新品种。 本文主要进行了HRB500钢筋的材料力学性能及其在混凝土中的粘结锚固性能的研究，以解决其在混凝土中的锚固设计问题。 钢筋的材性试验表明：HRB500钢筋的强度和伸长率不仅符合我国标准，且达到了欧洲规范的要求，适用于抗震结构。在混凝土结构设计中，HRB500级钢筋抗拉屈服强度标准值可取f_yk=500N／mm²，弹性模量E_s=2.1×10⁵N／mm²。 根据72个HRB500粘结锚固试件的拉拔试验，分析了混凝土强度、保护层厚度、锚固长度、配箍率等锚固条件对HRB500钢筋粘结锚固性能的影响，并经统计回归得到了HRB500钢筋在混凝土中的粘结强度计算公式，且与《混凝土结构设计规范》粘结锚固专题研究组提出的月牙纹外形热轧钢筋的极限粘结强度公式的计算结果吻合。 在试验的基础上，通过对现有粘结锚固τ-s本构关系的修订，得到了适用于HRB500钢筋的τ-s本构关系。 通过可靠度分析，提出了HRB500钢筋在混凝土中锚固长度的设计建议，结果表明：HRB500钢筋的设计锚固长度仍可按现行《混凝土结构设计规范》（GB50010—2002）规定的公式计算。更多还原

【Abstract】 HRB500 steel bar is a kind of hot-ribbed bar whose characteristic tesile strength is 500MPa. It is a new sort of steel with high strength and good ductility, and it was exploited through alloying drops of other special metals with steel in China.In this paper, we carried out the research about the mechanical capability, especially the bond-anchorage property in concrete of HRB500 steel bar to solve the problem on the anchorage design of HRB500 steel bar in concrete structures.The mechanical capability test proves that the stength and the elongation of HRB500 steel bar not only satisfy the requirements in Chinese standard, but also achieve the demands in Eurocode. So it can be used in seismic design structures. And in the design of concrete structure, the value of characteristic tensile yield strength fyk can be set as 500MPa, the value of modulus of elasticity Es can be set as2.1x105N/mm2.According to 72 pullout tests, the effects of concrete strength, thickness of concrete cover, anchorage length, and stirrup ratio etc. for the bond-anchorage property have been analysed. By way of experimental statistical regression, the calculating formula of ultimate bond-anchoring strength has been established. The result is in good agreement with what comes from the formula of crescent hot-ribbed bar proposed by the special bond-anchorage research group of Chinese "code for design of concrete structures’.Based on the above experiments and present τ-s constitutive relationships, the bond-anchorage τ-s constitutive relationship for HRB500 steel bar has been established.The design of anchoring length through reliability analysis has been proposed. The result shows that the anchoring length for HRB500 steel bar can be designed by the formula in existing "code for design of concrete structures"(GB50010-2002).更多还原