Reducing Environment Pollution by Reusing of Alum Sludge Waste in Stone Mastic Asphalt Mixtures

  • Omar T. Mahmood Department of Civil Engineering, Faculty of Engineering, Koya University, Daniel Mitterrand Boulevard, Koya KOY45, Kurdistan Region – F.R. Iraq
Keywords: Stone mastic asphalt, Alum sludge, Burned alum sludge, Dried alum sludge, Alum sludge reuse, Environment pollution


Globally, a huge quantity of alum sludge waste is produced as a by-product material from drinking water treatment plants that utilize aluminum salts as an essential coagulate and is the most generally produced water treatment remaining sludge around the world, which causes a serious environmental problem. Direct discarding of this substance has ecological effects. Hence, it is important to reuse this alum sludge waste material in such a manner to diminish its detrimental impacts on the environment. This research investigates the possibility of reusing alum sludge waste as a partial replacement of cement filler in stone mastic asphalt (SMA) paving mixtures. For this investigation, the alum sludge was used as a filler material in SMA mixtures in two modes; dried alum sludge at 110°C and burned alum sludge at 700°C. Different percentages of alum sludge were used as a replacement by the total weight of mineral filler at 0, 20, 40, 60, 80, and 100%. The results showed that using alum sludge as a substitution of filler in SMA mixtures reduces the performance of the mixtures in terms of Marshall properties and tensile strength for both dried and burned alum sludge compared with a standard mix. However, the performance of the mixtures containing burned alum sludge gave a better performance than the mixtures containing dried alum sludge.


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Author Biography

Omar T. Mahmood, Department of Civil Engineering, Faculty of Engineering, Koya University, Daniel Mitterrand Boulevard, Koya KOY45, Kurdistan Region – F.R. Iraq

Omar Taha is a Lecturer at the Department of Civil Engineering, Faculty of Engineering, Koya University. He got the B.Sc. degree in Building and Construction Engineering, the M.Sc. degree in Highways and Airports Engineering. His research interests are in pavement materials and soil stabilization. Mr. Omar is a member of the UAE Engineers Society.


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How to Cite
Mahmood, O. T. (2021) “Reducing Environment Pollution by Reusing of Alum Sludge Waste in Stone Mastic Asphalt Mixtures”, ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY, 9(2), pp. 76-82. doi: 10.14500/aro.10871.