预应力活性粉末混凝土-普通混凝土叠合梁疲劳全过程分析

为了推广活性粉末混凝土在桥梁工程中的应用，对预应力活性粉末混凝土（RPC）-普通混凝土（NC）叠合梁疲劳破坏的全过程进行分析. 建立NC、RPC、非预应力筋和预应力筋的疲劳损伤退化模型，结合分段线性法提出预应力RPC-NC叠合梁的疲劳全过程分析方法，并针对考虑RPC抗拉疲劳性能与否这2种情况分别进行计算. 为了验证该分析方法的有效性，对2根预应力RPC-NC叠合梁进行等幅疲劳循环加载，试验结果和计算结果的对比表明，当不考虑RPC抗拉强度时，非预应力筋应力的计算结果明显偏大，导致分析结果过于保守；在考虑RPC抗拉强度的情况下，使用该方法可以较为准确地描述预应力RPC-NC叠合梁的疲劳退化过程.

Full-range analysis on fatigue performance of prestressed reactive powder concrete-normal concrete composite beam

Full-range analysis on fatigue performance of prestressed reactive powder concrete (RPC)- normal concrete (NC) composite beams was performed, to promote the application of RPC in bridge engineering. Fatigue damage degradation models of NC, RPC, non-prestressed and prestressed reinforcement were established. The full-range analysis on fatigue performance of RPC-NC composite beams was presented combined with piecewise linear method, with the fatigue tensile resistance of RPC considered and ignored in calculation, respectively. Repeated loading with constant amplitude was carried out on two prestressed RPC-NC composite beams to verify the effectiveness of the full-range analysis method. Comparison between experimental and calculation results showed that the stress of non-prestressed reinforcement was significantly larger and the results were too conservative when fatigue tensile resistance of RPC was ignored. The fatigue degradation process of RPC-NC composite beams can be described accurately when fatigue tensile resistance of RPC was considered.