Evaluation of Compaction Energy, Soil Grain Distribution and Type of Steel Slag on the Compaction Characteristic and California Bearing Ratio (CBR)

Today, steel is one of the most used materials in industry and its annual consumption is increasing. One of the most important by-products of steel making is steel slag. The use of steel slag as a waste of this industry, can be applied in geotechnical  applications  such a road embankment in order to reduce of the slag disposal, as well as preventing the destruction of natural resources, is of particular importance. It is necessary to determine the geotechnical engineering properties of steel slag produced from different steelmaking operations and assess the potential usage in road and railways embankment construction.  In this paper, physical, compaction properties, California Bearing Ratio’s (CBR) and characteristics of steel slag as a base and sub base of road material and sub ballast of railway were studied. Two types of steel slag, Blast Oxygen Furnace (BOF) and Electric Arc Furnace (EAF) slags which produced in Esfahan Steel Company and Esfahan's Mobarakeh Steel Company respectively are used in this research. The range of the particle size distribution of the specimens has been selected in accordance with the characteristics of the road pavement as well as the existing laboratory facilities. In this research, California Bearing Ratio (CBR) tests were carried out on two types of slags (BOF, EAF) with two types of particle size distributions and with two different compaction methods (standard and modified) in soaked and un soaked conditions. Based on obtained results mentioned slag have no plasticity index. Moreover, dry unit weight varies between 1.94 to 2.74 gr/cm3 and optimum moisture content varied between 8% and 12.5%. The CBR values varied between 88 to 199 for BOF slags and 185 to 490 for EAF slags in socked and unsocked conditions. According to CBR test results; these materials can be used in road base and sub-base layers by applying less compaction effort than in normal condition.