Effect of petrographic composition and chemistry of aggregate on the local and general fracture response of cementitious composites

This paper concerns the results of research into the influence of the composition of rock inclusions on the fracture response of cement-based composite specimens. Specially designed specimens of the nominal dimensions 40 × 40 × 160 mm with inclusions intheshape ofprisms with nominal dimensions of 8 × 8 × 40 mm were provided with an initial central edge notch withadepth of12 mm. These specimens, which were made of fine-grained cement-based composite with different types of rock inclusion – amphibolite, basalt, granite, andmarble – were tested in the three-point bending configuration. Fracture surfaces were examined via scanning electron microscopy and local response in the vicinity of rock inclusions was characterized via thenanoindentation technique. Theaim of this paper is toanalyse the influence of the chemical/petrographic composition of rock inclusions on the effective mechanical fracture parameters of cement-based composites, as well as on the microstructural mechanical parameters oftheinterfacial transition zone. The results of this research indicate thesignificant dependence of the effective fracture parameters onthepetrographic andrelated chemical composition of the rock inclusions.