Effect of T-stress on the initial fracture toughness of concrete under I/II mixed-mode loading

The mixed-mode stress intensity factors (SIFs) and T-stress for different geometries of four-point bending specimens were calculated by means of finite element analysis through a software suite Abaqus, where the influence of the crack length, loading point and crack location were considered. Thereafter, a series of four-point bending tests were re-interpreted to account for the consequences of the T-stress on the initial fracture of concrete, where a generalized maximum tangential stress (MTS) criterion was employed. The results indicate that the inclusion of T-stress is essential to predict a more realistic initial fracture toughness of concrete subjected to mixed-mode I/II loading.