An extensive investigations on fracture parameters of concretes based on quaternary binders (QBC) by means of the DIC technique

The following article presents an extensive investigations of the fracture mechanics parameters of concretes made of quaternary binders (QBC). A composition of the two most commonly used mineral additives, i.e. fly ash (FA) and silica fume (SF) in combination with nanosilica (nS), has been proposed as a partial replacement of the ordinary Portland cement (OPC) binder. Four series of concretes were made, one of which was the reference concrete (REF) and the remaining three were QBC. During the studies KSIc and CTODc were investigated. In addition, digital image correlation (DIC) technique was used. Based on the conducted studies it was found that the QBC containing: 80% OPC, 5% FA, 10% SF, and 5% nS have shown the best results of KIc and CTODc, whereas the worst parameters were characterized by concrete with more content of FA additive in the concrete mix, i.e.,15%.