Evaluation of the Cooling and Pavement Performance of Basic Oxygen Furnace Slag Used in Asphalt Mixture

Abstract

Basic oxygen furnace slag (BOF) is widely used in road construction, but there is a lack of characteristics in different asphalt mixtures. This study investigates the properties of hot-mixed asphalt (HMA), containing stone mastic asphalt (SMA), porous asphalt (PA), and dense-graded BOF as a partial substitution for natural aggregates. The purpose of this study is to evaluate various BOF slag contents in the asphalt mixtures that would affect the cooling behavior after compaction. Asphalt mixture specimens contained 0%, 20%, 40% and 60% BOF slag, respectively, as coarse aggregate. Test results showed that BOF slag has a lipophilic property, so that it can be adsorbed by asphalt cement, thereby reducing the cost of asphalt. The stability value of all the asphalt mixtures increases with the proportion of BOF slag replacement. In addition, the voids in the mineral aggregate (VMA) value variable exhibited significant differences among asphalt mixtures, and could determine the deviation of the cooling trend of asphalt mixtures. Furthermore, it was found that the cooling procedure of the BOF slag used in dense-graded asphalt mixture takes about 100 min, and that the temperature tends to be moderate; however, it took about 120 min of cooling the SMA and PA mixture with BOF slag. In addition, the distribution of voids of the dense asphalt mixture was not uniform. This would result in various locations of inconsistent thermal energy temperature on asphalt mixtures.

Mechanical performance of sustainable asphalt mixtures manufactured with copper slag and high percentages of reclaimed asphalt pavement

“…Researchers have studied the incorporation of different types of materials and design methodologies to avoid an excessive increase in the stiffness modulus, which is a characteristic of mixtures with high RAP content that can affect long-term performance, turning them into a brittle material susceptible to the appearance and propagation of cracks. The use of rejuvenating additives (oils and waxes) [24,25], polymer modified binders [26,27] or lower grade PG (stiffness compensation) [10], the use of warm mixtures (reduction of short-term aging of RAP) [28,29] and the use of stabilizing additives (slag, fibers, and minerals) [30][31][32][33][34][35] are some of them. On the one hand, these techniques make it possible to counteract the aging of RAP by controlling its viscoelasticity and, on the other hand, to stabilize the behavior of RAP mixtures against the phenomena of loss of adhesiveness due to moisture conditions, fatigue damage, and permanent deformation, the main causes of deterioration of this type of mixtures [36].…”

Effects of basicity, MgO and MnO on mineralogical phases of CaO–FeOx–SiO2–P2O5 slag

“…The utilisation of steelmaking slag has received increasing attentions in recent years. [1][2][3][4][5][6][7][8][9] Many techniques have been proposed to treat and utilise steelmaking slag. [2][3][4][5][6][7][8][9] Among these, magnetic separation of steelmaking was a promising technique to separate steelmaking slag into magnetic phases and non-magnetic phases.…”

“…[1][2][3][4][5][6][7][8][9] Many techniques have been proposed to treat and utilise steelmaking slag. [2][3][4][5][6][7][8][9] Among these, magnetic separation of steelmaking was a promising technique to separate steelmaking slag into magnetic phases and non-magnetic phases. [6][7][8][9] The magnetic phase could be recycled in process of ironmaking, e.g.…”

Study on Recycling of Steel Slags Used as Coarse and Fine Aggregates in Induction Healing Asphalt Concretes

“…Studies indicate that steel slag formed by crushing and proper process has a similar shape to the natural aggregates [15] and better mechanical properties [16], so it has the potential to become an aggregate for road building materials. The mechanical characteristics [17,18] and pavement performances [19] such as moisture stability [20,21], skid resistance [21,22] and crack resistance were improved with steel slag applied as a coarse aggregate in asphalt mixtures. However, steel slag replaced as a fine aggregate is not suggested owing to some poor performances and high cost factors.…”