超细晶粒钢筋粘结锚固性能的研究

【作者】 李千；

【导师】 徐有邻； 刘立新；

【作者基本信息】 郑州大学 ， 结构工程， 2007， 硕士

【摘要】 超细细晶粒钢筋是我国新研究开发的采用控制钢筋轧制温度技术生产的一种新型细晶粒钢筋，它具有强度高延性好的特点。本文主要进行了超细晶粒钢筋（500 MPa与400 MPa级两种）的材料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。钢筋的材性试验证明，超细晶粒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，可以适用于抗震结构。在混凝土结构设计中，500级超细晶粒钢筋抗拉屈服强度标准值可取f_yk=500 N／mm²，弹性模量E_s=2.1×10⁵N／mm²。根据对48个超细晶粒粘结锚固试件和18个对肋与错肋钢筋试件的拉拔试验，分析了混凝土强度、保护层厚度、锚固长度、配箍等条件对超细晶粒粘结锚固性能的影响及肋的位置不同对粘结锚固性能的影响。并经统计回归得到了超细晶粒钢筋及对肋与错肋钢筋的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。通过可靠度分析，提出了超细晶粒钢筋在混凝土中的锚固长度的设计建议，结果表明超细晶粒钢筋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。本课题为863计划资助课题（2004AA33G050）。更多还原

【Abstract】 Ultra-fine grain steel bar is a new kind of close grain hot-ribbed bar which is made by controlling the temperature of rolling.It has many kinds of characteristics such as high strength and good ductility .In this paper , we carried out the research about the mechanical capability（including 400 MPa and 500 MPa steel bar）, especially the bond-anchorage property in concrete of ultra-fine grain steel bar steel bar to solve the problem on the anchorage design of this new kind of steel bar in concrete structures.In addition,we carried out the research about the bond-anchorage property of symmetric-ribbed bar and asymmetric-ribbed bar .The mechanical capability test proves that the strength and the elongation of ultra-fine grain 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 values of characteristic tensile yield strength f_yk can be set as 500 MPa , the value of modulus of elasticity E_s can be set as 2.1×10⁵ N/mm².According to 48 pullout tests of ultra-grain steel bars and 18 pullout tests of the symmetric-ribbed bar and asymmetric-ribbed bar ,the effects of concrete strength , thickness of concrete cover , anchorage length , and stirrup ralio 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 structure.The design of anchoring length through reliability analysis has been proposed , the result shows that the anchoring length for ultra-fine grain steel bar can be designed by the formula in existing code for design of concrete structures （GB50010-2002） .更多还原