Investigation of Size-Independent Fracture Energy of Cementitious Materials by Quantifying the Deformation Energy

Abstract

As an intrinsic parameter, the fracture energy of a material with a designated mix proportion should be constant; however, the size effect considerably affects fracture energy research. Deformation energies outside the fracture surface consume some of the input energy, which was ignored, and these were found to be the main cause of the size effect on fracture energy. In this study, the fracture energies of samples with different sizes were investigated , and the fracture areas were accurately measured using a 3D scanning measurement system (SMS). The internal volumetric strains were then indirectly obtained by DIC, and a calculation method to determine the deformation energy of a cementitious material was proposed based on the obtained volumetric strains. The results showed that the fracture energies of samples of different sizes, when deformation energy was considered, were approximately consistent. Thus, the size effect problem on fracture energy was effectively resolved.

Keywords: Cementitious materials, fracture energy, size effect, deformation energy, digital image correlation