This manuscript aims to investigate the effect of hydration characteristics, textural properties and fire resistance of cement pastes containing Fe2O3 nano-particles (NF). NF prepared from C2FeO4.2H2O at 300 and 500 °C at heating rate 5 °C min−1 for 2 h soaking time. TEM shows the crystal size of NF was 10–20 nm, with surface area of 50.51 m2 g−1. The cement mixes were prepared with 0, 1, 2 mass% NF with water/cement ratio of 0.35. The values of compressive strength and chemically combined water content of OPC–NF pastes up to 1 mass% show higher values than those of neat pastes. Increasing the content of NF up to 2 %, the chemically combined water content decreases, but still higher than that of the neat OPC paste. The free lime content of OPC paste increases, whereas the cement pastes containing NF decrease. SEM micrograph depocits the presence of fibrous C–S–H gel, forming interlocking dense and compact fibrous C–S–H gel. The compressive strength of thermally treated cement pastes increases up to 400 °C, then decreases up to 600–1000 °C, due to the decomposition of C–S–H and CH. It can be concluded that 1–2 % NF enhances the fire resistance of OPC cement pastes. |
