The Effect of Electric Arc Furnace Dust (EAFD) on Improving Characteristics of Conventional Concrete

Abstract

The steel industry is one of the key industries and its use is inevitable in many industries including construction. In addition to steel, this industry produces massive amounts of electric arc furnace dust (EAFD) that is classified as hazardous waste. Using this material as an admixture can improve the characteristics of concrete, neutralize potential risks and be beneficial to the circular economy. Considering the differences in EAFD between different steel companies, which in turn is caused by the type and percentage of input materials, the optimal percentage and specific application of EAFD from steel companies of each region is unique. In the present study, samples from 11 different sources of EAFD in Khuzestan Steel Company (KSC) were collected. Then, they were classified into three groups depending on the size and origin (fine and coarse, both obtained by filtering those particle sizes directly from furnaces, and a third class obtained in the interior of the steelmaking site close to material handling (MH) belt conveyors) based on their physical and chemical characteristics. To test the effect of EADF as an admixture, several conventional concrete samples were prepared by replacing 0% (control), 2%, 5% and 8% of cement with each EAFD group. Finally, the resulting material was characterized through several tests, namely: (i) compressive strength test at 7, 28 and 90 days, (ii) depth of water penetration under pressure test and (iii) electrical indication of concretes ability to resist chloride ion penetration. The result shows that replacing 2% of the cement with MH caused the largest improvement in compressive strength of 7 day concrete, but also showed negative effect on water penetration, while coarse had a negative effect in almost all tests except in the chloride ion penetration test. The best results were obtained by replacing with 2% of cement with fine EAFD, showing significant improvements in all tests, as well as in the observed trend of increasing compressive strength over time.