Investigation of Rutting Performance of WMA Mixtures Containing Copper Slag

Copper slag (CS) is an abrasive blasting grit made of granulated slag from metal smelting processes. Ascopper slags are known to be waste material and cause a lot of environmental problems, it would be a goodidea to use them in different sections of industry such as pavement construction. On the other hand, in orderto save energy and reduce the amount of pollutants released during the construction of asphalt pavements,the technology of Warm Mix Asphalt (WMA) is developing considerably. A very high amount of copperslag is produced in south of Iran where the weather is considered to be hot and rutting is the most importantdistress of asphalt concretes. This paper presents the influence of utilization of copper slag as fine materialon the rutting performance of warm mixed asphalt. A laboratory study has been conducted on five asphaltmixtures with various CS contents, namely; 0%, 10%, 20%, 30% and 40% by weight of total aggregates. Theamount of optimum bitumen and the value of Marshall Stability (MS) were determined with MS test for thesamples. Then creep test and wheel track tests were conducted on the produced samples. The resultsindicated that the use of 20% CS in WMA enhances the marshal stability and rutting performance of WMAmixtures. However, the resistance of mixtures against rutting falls substantially by adding more than 20%CS.

Keywords:

Copper slag , warm mix asphalt , by-products in asphalt mixtures , moisture sensitivity , creep test