• Influence of aggregate size on the propagation of concrete type Ⅰ fracture cracks

    Subjects: Mechanics >> Solid Mechanics submitted time 2024-04-19 Cooperative journals: 《应用力学学报》

    Abstract:
    In order to study the propagation characteristics of type Ⅰ fractures of concrete with different aggregate sizes,concrete three-point bending beam fracture tests with the maximum aggregate size of 10,20,30,40 mm were carried out,and the data of full-field strain and displacement changes in the calculated area on the specimen surface were measured by using digital image correlation techniques to investigate the changes and development of fracture energy,fracture toughness and fracture process zone of concrete with different aggregate sizes.The relationship between the FPZ extension process and the post-peak loading was investigated.The results show that with the increase of the aggregate size,the compressive strength,peak load and fracture parameters of the specimens show a trend ofincreasing first and then decreasing,and the change of FPZ length of M20 specimens has a strong correlation with post-peak load,and the aggregate has the best restraint effect on microcracks,In addition,by analyzing the development law of FPZ of concrete specimens with different aggregate sizes,it can be learned that specimens with the aggregate size of 20 mm have an improved local deformation capacity after peaking,enhanced fracture energy and fracture toughness,higher bearing capacity and smaller FPZ in the fracture process than other aggregate sizes concrete; therefore,the suitable aggregate size is 20 mm.