Experimental Study on Thermal Conductivity of Concrete Using Ferronickel Slag Powder

Insulation performance of concrete must be secured in order to minimize the energy loss of buildings. For enhancing the insulation performance of concrete, this study conducts research on thermal conductivity of concrete using the Eco-friendly material called ferronickel slag (FNS) binder, and compares the mechanical properties and insulation properties to the concrete using ordinary Portland cement (OPC). According to the tests results, the compressive strength of 91days 100%OPC and 30%FNS concrete were 36.4 and 36.3 MPa, respectively. Given that the activity of FNS is almost equal to the 100%OPC at the long-term curing period, it appears that the unhydrates and pore water from the secondary hydration reaction have negligible influence on the mechanical property of concrete. The test result also shows that 91days 100%OPC and 30%FNS concrete have insulation performance of 1.59 and 1.10W/mK, respectively, indicating that thermal conductivity of FNS is 31% lower than that of OPC. The lower thermal conductivity of FNS appears to be caused by uniform heat transfer resulted from the presence of unhydrates, surplus water, and pores, at the level of avoiding degradation the structural performance. Therefore, it is concluded that insulation performance of concrete is improved by the use of FNS.