活性粉末混凝土受弯构件中钢筋粘结性能

Bond properties of reinforcement anchored in reactive powder concrete flexural members

摘要:

为了研究活性粉末混凝土构件中钢筋的粘结特性,采用梁式试验方法分析了各因素对粘结性能的影响,建立了粘结应力-滑移本构模型,并与普通C40混凝土进行对比．研究表明:活性粉末混凝土试件与C40混凝土试件的粘结应力-滑移曲线整体规律相同,活性粉末混凝土的抗压强度及粘结强度都远大于普通混凝土,其中极限粘结强度τu约为C40混凝土的3倍,其对应的滑移值su约为C40混凝土的2倍,相对粘结强度τu/fcu约为C40混凝土的1.6倍;根据试验曲线及试件破坏过程对活性粉末混凝土与钢筋之间的粘结机理进行分析,并根据试验数据统计回归出多因素影响下锚固特征值的经验公式,建立了四折线的粘结应力-滑移本构模型．

Abstract:

Bond properties between reactive powder concrete and steel bar are studied through beam bond tests, and compared with C40 concrete. It is showed that, the bond stress-slip curve tendency of the two concretes is similar, and the compressive strength and bond strength of reactive powder concrete are much larger than that of C40 concrete. The ultimate bond stress of reactive powder concrete τu is about three times of C40 concrete, the responding slip su is about twice of that of C40 concrete, and the relative bond strength τu/fcu is about 1.6 times of that of C40 concrete. The bond mechanism between reactive powder concrete and steel bar is analyzed according to the test curve and failure mode, at the same time, an empirical formula including multifactor are established through statistical regression, and a simplified four-line bond stress-slip model is established that can provide a reference for engineering design.