An overview on performance of steel slag in highway industry

Transportation and highway industry are going to us e sustainable and recycling materials to address the two global issues: environment and e nergy. One of the materials is steel-furnace slag, a sustainable waste material, which includes two ty pes, i.e. compound aggregate brought out as a consequence of Electric Arc Furnace (EAF) and Basic Oxygen Furnace (BOF). Steel slag can replace the traditional aggregates because it has a feature that is almost the same to those traditional aggregates and it is easily secured as a by-product from the steel industry. The recent experimental researches in preliminary studies have demonstrated chemical, mechanical and physical and properties of the steel slag. California bearing r atio (CBR) value of steel slag is between 200 and 300%, whereas CBR of crushed aggregate is only from 80 to 100%. Furthermore, asphalt mixture using steel slag presents better mechanical charact eristics than those of the corresponding asphalt with 100% natural aggregate. The combination of 30% steel slag and 70% natural aggregates in bitumen mixture shows excellent performance as surf ace course of roads. Hence, the operation of steel slag in road construction reduces land fill, saves natural resources and improves the strength o f the pavement to sustain a heavier and higher volume of vehicles. The overall purposes of this review paper are collecting the chemical, physical and mec hanical characteristics of steel slag for illustrating its performance, highlighting the prev ious studies on the use of steel slag in road construction and the effect of different percentage of steel slag upon pavement as a replacement for natural aggregates