Recycling of engineering characteristics of basic oxygen furnace slag and used as base layer material

Basic oxygen furnace slag (BOF) is a by-product generated in the process of steel making. Since it is swellable, its usage is limited. The result of research shows that, both the wet-binder method and the substitution wet-binder method can reduce the swell of BOF. The swell rate and CBR value of BOF treated with any of the two methods can satisfy the graded quality requirement of road bases and sub-bases layer, and the heavy metal leaching value is far lower than the leaching standard, complied with the environmental quality requirements. The researcher laid the treated BOF on Tai No.27 Line in Wangdan Township, Pingtung County. Six engineering methods are adopted, and separately they are: not treated (pure BOF), BF substitutes 100% fine grains of BOF and wet-binder, power plant bottom ash substitutes 100% fine grains of BOF and wet-binder, cement and bottom ash wet-binder, cement and fly ash wet-binder, and cement and slag power wet-binder. Besides, soil layer expansion plat, earth's surface observational station, and groundwater monitors well are used to perform environmental background survey. From the results of trial laying we find that, when wet-binder or substitution wet-winder method is used, a 100% compaction degree can be reached after 10-14 cycles of rolling; the swell rate is 0.01%-0.06%; the pH value of underground water is 6.8-7.25; the leaching value of heavy metals like cadmium, chrome, copper, zinc, nickel, lead, hydrargyrum, and arsenic is much lower than the second category underground water monitoring standard and control criterion and, therefore, will not cause negative effect to the quality of underground water. The results of experiment are just provided as reference for engineering design and construction.