This study investigated the fire resistance performance in terms of physical and chemical properties of the cement paste incorporating an iron by-product (i.e., ferronickel slag; FNS) at elevated temperatures (200 °C, 400 °C, 600 °C, and 800 °C). The cement pastes partially replaced with FNS, ground granulated blast-furnace slag (GGBS), and pulverized fly ash (PFA) at 30%, 60%, and 30%, respectively, were fabricated to compare the performance with other pozzolanic binders. All the pastes were kept at the water to binder ratio (W/B) of 0.467. The specimen was cured for 28 days and exposed to set temperatures. After/before heating, compressive strength and mercury intrusion porosimetry (MIP) were measured to evaluate the fundamental properties. Simultaneously, a variation in phase composition was examined using X-ray diffraction (XRD) and thermogravimetry (TG). As a result, despite lower strength at room temperature for the blended paste, those specimens were always higher than ordinary Portland cement (OPC) one after heating. Among them, FNS modified paste ranked the highest value in the residual strength after 400 °C, indicating 30.7% at 800 °C, which is consistent with a change in porosity and average pore size. This may be attributed to the presence of hydrotalcite and ferric/ferrous hydroxide, which is observed in the XRD results of FNS incorporated paste even after exposure to high temperatures. However, the optimum replacement level of FNS powder should be verified to secure a better performance in the given and a more severe temperature environment.
Bibliographical noteFunding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea ( NRF ) funded by the Ministry of Education ( NRF-2019R1A6A3A01094029 ) and also supported by a project titled “Verification of replace ratio improvement with fused by-product, developing prediction method for material characteristic and reviewing of heat transfer improvement analysis for PosMent-FN” from POSCO E&C in the Republic of Korea.
© 2021 The Authors
All Science Journal Classification (ASJC) codes
- Materials Science (miscellaneous)