The effect of nanosilica on the mechanical properties of polymer-cement composites (PCC)

摘要

In the last decade nanomaterials due to their unique physical and chemical properties, have attracted the interest of researchers to fabricate new building materials with novel functions. One of the most referred to and used cementitious nanosized materials is nanosilica (nSiO2). Although the number of publications devoted to the influence of nanosilica on the properties of cementitious composites has increased over the course of the last decade, the field of polymer-cement composites (PCC) has remained under-studied. Therefore, this paper will deal with the potential application and the influence of nanosilica (nSiO2) on the mechanical properties of PCC. In this study the influence of diameter (100 nm and 250 nm) and quantity (1%, 3%, 5% by weight of cement) of nSiO2 on the consistency and mechanical properties of polymer-cement mortars (PCC) have been examined. Moreover, the hydration of cement compounds was followed by X-ray diffraction (XRD). Studies have shown that the addition of nanosilica has great potential to accelerate the pozzolanic reaction, thus reacting more with the CH and increasing conversion of C-S-H, and having the potential to improve mechanical properties of PCC. The obstacle overcome is the high water demand of nanosilica particles, leading to significant deterioration of consistency. Finer particles of nSiO2 seem to be more effective and cause fewer problems with the consistency of fresh mortars.