Ahmedzade, P., & Sengoz,
B. (2009). Evaluation of steel slag coarse aggregate in hot mix asphalt
concrete. Journal of hazardous materials, 165(1-3), 300-305. doi:10.1016/j.jhazmat.2008.09.105
This article focuses on the influences of the utilization of
steel slag as a course aggregate on the properties of hot mix asphalt. Ahmedzade’s
and Sengoz’s main aim of this article seems to be to convince readers of the great
effects of substituting coarse and fine aggregates in asphalt mix with steel
slag aggregates. Steel slag, a by-product of steel making has been utilized in
a number of applications in the civil engineering industry. For paving mixes, steel
slag should be limited to only replace either the fine or coarse aggregate
fraction, but not both. Steel slag has an angular shape, and for this reason,
hot mix asphalt containing 100% steel slag is susceptible to high void space
and bulking problems and will also be prone to over-asphalting during production
and subsequent flushing due to in-service traffic compaction. In this study, four
different asphalt mixtures containing two types of asphalt cement (AC-5 &
AC-10) and course aggregate (limestone & steel slag) were used to prepare
Marshall specimens and to determine optimum bitumen content. The limestone
aggregate was procured from quarries around Elazig while the steel slag was directly
obtained from Erdemir Steel Manufacturing Factory. Different tests were conducted
to evaluate the mechanical characteristics of all mixtures. Such tests were Marshall
stability, flow and Marshall quotient, indirect tensile stiffness modulus, creep
stiffness, indirect tensile strength and resistance to moisture damage. Electrical
resistivity of the specimens was also measured on Marshall specimens by electrical
resistivity testing apparatus and in accordance with ASTMD257-91. Scanning electron
microscope was used to observe the surface texture of steel slag and limestone
where it was seen that plenty of pores were on the surface steel slag which implies
that steel slag is a kind of porous material. From the results obtained from
the different tests conducted, it was observed that steel slag used as a course
aggregate improved the mechanical properties of asphalt mixtures. The results
indicated that steel slag mixtures have excellent engineering properties and
good electrical conductivity. AC-10/SS asphalt mixture showed the best performance among the tested mixtures. Moreover, the volume resistivity values showed
that steel slag electrical conductivity were better than that of limestone
mixtures.