Study on the durability of concrete with FNS fine aggregate

As a by-product of nickel production, the ferronickel slag (FNS) puts a lot of pressure on the environment. It is becoming more and more urgent to deal with the increasing FNS. The aim of this study is to explore the durability of concrete with FNS fine aggregate. Two kinds of FNS with different storage time were selected. The radioactivity detection, XRD test and stability detection of FNS were conducted to ensure FNS can be used as construction materials. Then the durability of concrete with 13%, 27%, 40% and 50% FNS (by weight of fine aggregate) was investigated, respectively. It was found that the properties of concrete prepared from FNS with different storage time had little difference. The results indicated that 27% FNS replacement showed improvement in resistance to sulfate attack by 22% but the resistance to chloride ion penetration was not significantly influenced. Moreover, 40% FNS addition brought a 33% abrasion reduction than that of original concrete. SEM analysis showed that FNS produced more C-S-H gels and improved the microstructure of concrete. This study indicated that proper content of FNS can be used as fine aggregate and it was beneficial to the durability of concrete, especially to the abrasion resistance.