T-stress's Effect on the Fracture of Concrete

The interface between aggregate and cement was an important role in determining the properties of concrete. Cracks, which arose in the interfacial aggregate mortar transition zone, propagate mainly in cement matrix in the surrounding area of the concrete aggregate. A new method was presented to describe the mixed fracture of the concrete. The effect of the non-singular term of stress, often known as the T-stress, on the angle of initiation of fracture and the fracture toughness is explored. A modified version of the T-stress based fracture model was proposed. The results show that the angle of initiation of fracture and the fracture toughness will change with T-stress. It is shown that the deviation angle increases for the positive T-stress. The theoretical results show that the apparent fracture toughness decreases significantly when T-stress is negative. The theoretical results are compared to the solutions obtained from finite element analysis. Excellent agreements have been achieved for the cracks.