Laboratory Investigation of the Steel Slag Aggregates Effect on Characteristics of Microsurfacing Surface Treatment

Microsurfacing is a mixture of polymer-modified emulsified asphalt, 100% manufactured well-graded fine aggregate, mineral fillers, water and chemical additives used in the preventive maintenance of pavements. One of the components that have a significant effect on the microsurfacing performance is aggregate, which comprises about 82 to 90 percent by weight of the mixture. This research presents experimental results with the aim of effecting the use of steel slag to improve microsurfacing characteristics. Therefore, in this research, 100% silica aggregate was used as a control mixture and then steel slag was replaced by 42.5%, 61% and 100% aggregate of control mixture. This study was carried out through wet cohesion test, wet track abrasion test and lateral displacement by loaded wheel test. The results of the wet cohesion test and wet track abrasion test indicated that mixtures containing steel slag aggregates compared to the control mixture due to the desired mechanical, physical and chemical properties, would improve the microsurfacing performance, including increasing the adhesion of bitumen to aggregate and increasing the abrasion resistance. Also, in the test of determining the displacement by the loaded wheel, the lowest displacement in the mixture containing 61% of the steel slag was observed and reduced the vertical and lateral displacement by 45.65% and 35%, respectively, compared to the control mixture.