Effect of the simultaneous addition of silica fly ash and waste granite powder on selected properties of cementitious surface layers in composite floors with concrete substrate

The adhesion of the surface layer to the subbase determines its functional, mechanical and durability qualities. The purpose of this study is to test the possibility of replacing up to 30% of the cement in the cement mixture used for the surface layer with the simultaneous addition of granite powder and siliceous fly ash, and to determine the optimal quantitative use of them. Ten test plots were carried out, where each was made from a different material series. Standard tests and a pull-off adhesion determination test were used. The results show that the optimal percentage replacement of cement is 30% with the addition of 20% ash and 10% granite powder, obtaining the highest density of the composite and the highest adhesion of the surface layer to the primer (up to 10% higher than the reference series). These results highlight the synergistic effect of the simultaneous addition of pozzolanic material (silica fly ash) and filler (waste granite powder). We also observed that wet conditions of surface layer care directly determine the provision of its required properties, given its use. The research highlights the applicative nature of the method used and indicates the possibility of industrial application of the developed solution with a noticeable benefit to the surface layer due to its greater durability.