关键词: 活性粉末混凝土, 累积残余应变, 疲劳损伤

Abstract:

In order to reveal the fatigue damage mechanism and to establish a fatigue damage model of reactive powder concrete, axial equiamplitute pulsating loads are imposed to reactive powder concrete prism specimens, and the failure pattern and macro-crack evolution of the specimens at four different stress levels are observed. Then, the development of longitudinal strain with the loading is measured. The results show that the fatigue damage of reactive powder concrete develops from a nucleation stage to a stable stage and further to an instability stage, and that there is no macro-damage till the cyclic number of load exceeds a threshold. Moreover, a damage variable is defined according to the cumulative residual plastic strain, and some fatigue damage curves are plotted according to the experimental data. Finally, based on the theory of damage mechanics, a fatigue damage model of reactive powder concrete with simplicity and rationality is established for engineering application, with its parameters being also determined.

Key words: reactive powder concrete, cumulative residual strain, fatigue damage