In this research, to assess the impact of aging on the fracture properties of recycled aggregate concrete (RAC), three‐point bending tests were carried out on 260 specimens. Then, work of fracture method (WFM), size effect method (SEM), and boundary effect method (BEM) were utilized for analysis of fracture parameters. The result showed that fracture energy values for RAC were 4.2%, 7.1%, 22.7% and 24.2% less than natural aggregate concrete (NAC) ones at 3, 7, 28 and 90 days, respectively. Based on calculation of the characteristic length, the behavior of RAC is more ductile than NAC at early ages. However, through time, the ductility of RAC becomes less than NAC. On average, the ratio of fracture energy achieved from WFM (G_F) to initial fracture energy achieved from SEM (G_f) for RAC and NAC was 2.38 and 2.14, respectively. The comparison of fracture energy obtained by BEM and modified WFM showed that these values were close to each other.

中文翻译：

---

三种方法老化对再生骨料混凝土断裂特性的影响

在这项研究中，为了评估时效对再生骨料混凝土（RAC）断裂性能的影响，对260个样品进行了三点弯曲试验。然后，利用断裂法（WFM），尺寸效应法（SEM）和边界效应法（BEM）对断裂参数进行分析。结果表明，RAC的断裂能值在第3、7、28和90天分别比天然骨料混凝土低4.2％，7.1％，22.7％和24.2％。根据特征长度的计算，RAC的行为在早期比NAC更具延展性。但是，随着时间的流逝，RAC的延展性变得小于NAC。平均而言，WFM（G _F）达到的断裂能与SEM（G（G）达到的初始断裂能之比RAC和NAC的_f）分别为2.38和2.14。通过BEM和改进的WFM获得的断裂能的比较表明，这些值彼此接近。