Concrete fracture considering aggregate grading

•A fracture model for concrete is proposed combining the advantages of SEM and BEM.•Effect of concrete aggregate grading on fracture can be statistically determined.•Δafic at Pmax of geometrically similar specimens is determined through quantitative research.•Aggregate size, water to cement ratio, and coarse aggregate volume are considered. Combining the advantages of the size and the boundary effect models, an improved fracture model for determining the material parameters of concrete is proposed in this paper, considering concrete aggregate grading. The simple method for determining the fictitious crack growth length at peak loads of concrete specimens is identified through quantitative research. The independent fracture toughness and tensile strength of concrete can be determined with the maximum value of correlation coefficients in curve fitting, and the effect of maximum aggregate size, water to cement ratio, and coarse aggregate volume on fracture can be fully considered. A total of 300 self-compacting concrete specimens are used for analysis to verify the applicability and feasibility of the proposed model. The full structural fracture failure curves of concrete with upper and lower limits covering the experimental peak loads are established on the basis of the normal distribution methodology.