RETRACTED: Mechanical properties of EAFS concrete after subjected to elevated temperature

Abstract

Recycling of materials has become a major interest. Recently, the amount of slag deposited in the storage yard adds up to millions of tons/year leading to the occupation of farmland and serious pollution to the environment. Electric Arc Furnace slag (EAFS) is made at 1500–1650 °C having a honey comp shape with high porosity so it is expected to be good at fire resistance. Using EAFS as a partial replacement of the natural aggregate can be considered a good alternative for sustainable construction because its cost is very low. Although the existence of a high void ratio, this slag showed high compressive strength when using it as a partial replacement of natural aggregate in conventional concrete due to its good strength characteristics. This study investigates the behavior of using EAFS as a partial or fully coarse aggregate replacement by weight with different percentages of 0%, 15%, 30%, 50%, and 100% in concrete when subjected to elevated temperatures. Six groups of concrete mixes were prepared using various replacement percentages of slag exposed to different temperatures of 400 °C, 600 °C, and 800 °C for different durations of 1hr, 1.5hr, and 2hr. Evaluation tests of EAFS performance as a partial or full replacement of natural aggregate in concrete were compressive strength, tensile strength, and bond strength. The steel slag concrete mixes showed weak workability lower than the control mix. A systematic increase of almost up to 21.7% in compressive strength, and 66.2% in tensile strength with increasing the percentage of EAFS replacement to 50%. The experimental results showed that EAFS enhances the concrete properties and the fire resistance as confirmed by Thermal Gravimetric Analysis (TGA). The high void ratio and the slag components are the causes of this fire resistance enhancement result in improving the durability of concrete.