活性粉末混凝土的疲劳性能试验研究

Experimental Research on the Fatigue Performance of Reactive Powder Concrete

通过等幅单向压缩荷载作用下的活性粉末混凝土疲劳试验,研究活性粉末混凝土的疲劳特性。研究表明:循环荷载作用下,活性粉末混凝土的疲劳破坏表现为形成单一临界疲劳主裂纹的破坏形态;活性粉末混凝土的宏观疲劳损伤过程按宏观疲劳裂纹演变模式分为裂纹潜伏、裂纹稳定扩展和失稳破坏3个阶段,且各阶段分别占疲劳总寿命的15%,75%和10%,相应的纵向变形发展也呈此3阶段规律;活性粉末混凝土的疲劳寿命服从两参数Weibull分布,疲劳极限强度可取为其静极限轴心抗压强度的57%;活性粉末混凝土疲劳变形模量的衰减可分为平稳缓慢衰减和急剧不稳定衰减2个阶段,其比例分别为90%和10%;疲劳变形模量的极限值可以取作初始变形模量的0.5倍。

Based on the fatigue tests of reactive powder concrete （RPC） specimens under constant amplitude unidirectional compression loading, the fatigue property of RPC is studied. The experiments results show that the fatigue failure pattern of RPC specimens is a mode with single critical crack under cyclic loading. The development of macro-damage of RPC can be divided into latency stage, stable development stage and instability development stage according to the evolution pattern of the fatigue crack. Accordingly, the development of longitudinal deformation presents the similar three-stage-model, and the proportion of each stage is respectively 15%, 75% and 10% of the total fatigue life. The fatigue life of RPC accords with the two-parameter Weibull distribution. The fatigue ultimate strength of RPC is 57% of the static ultimate axial compression strength. The deterioration of fatigue deformation modulus can be divided into stable decreasing stage and unstable decreasing stage, and the proportion of each stage is 90% and 10%. The extreme value of the fatigue deformation modulus of RPC can adopt 50% of the initial deformation modulus.