Further observations on the three-parameter R-curve of concrete-like quasi-brittle materials

A three-parameter R-curve method for crack propagation study of concrete - like materials has been recently proposed in the literature. However, it needs to be systematically studied with respect to effect of specimen size, specimen shape, initial crack length/depth ratio and initial cracking fracture energy. For this purpose two specimen geometries viz. three point bend test and compact tension specimen of size-range 100 ⩽ D ⩽ 500 mm and ao/D ratio ranging 0.3-0.4 are considered. The input parameters are obtained using the developed fictitious crack model. Apart from other interesting results, it is found that a two-parameter R-curve based on size effect model can adequately predict the fracture response of the pre-cracked concrete specimen.