Maximum aggregate size effects on the evolution of the FPZ and crack extensions in concrete-Experimental and numerical investigation

In this paper, an experimental/numerical investigation is proposed to study the effect of maximum aggregate size (Dmax) on the fracture process zone (FPZ) length variations and the crack extension. Experimentally, three-point bending tests have been realized on plain concrete with different maximum aggregate sizes under crack mouth opening displacement (CMOD) control. The crack growth is monitored using the acoustic emission (AE) tech-nique. The numerical investigation is conducted at a mesoscale level. From the evolution of cohesive tangential stresses along the crack path, the variation of FPZ is explored. The crack extensions are investigated using the equivalent linear elastic fracture mechanics approach (LEFM) to investigate the R-curves. The results show a great influence of the maximum aggregate size both on the FPZ variation and on the global behavior.