The purpose of this study is to investigate the strength development of dredged marine clay stabilized with basic oxygen furnace (BOF) steel slag from early curing to later curing times using the shear wave velocity. The vane shear test (LVS), unconfined compression test (UCS) and bender element tests were performed with various conditions including the BOF slag contents and initial water contents to obtain the strength and shear wave velocity. The results of this study demonstrate that the strength and shear wave velocity could be classified into three zones: inactive zone, active zone and moderate zone. It concluded that the strength of BOF slag-treated dredged marine clay can be usefully monitored through the relationship between the strength and shear wave velocity.
A large number amount of clayey soils has annually been dredged from the maintenance of navigation channels and seaports. Even though the recycle of dredged clay has been attempted in various fields (Yilmaz and Civelekoglu 2009); (Saride et al. 2013); (Kang et al. 2017a), it is very difficult to apply due to low strength, high water content and high compressibility without the binders. Hence, in the practical terms, the dredged clay could be reused with hardening by using stabilizers, such as cement and lime as filling and reclamation materials (Saride et al. 2013); Kang et al. 2017b).
Meanwhile, basic oxygen furnace (BOF) steel slag is an industrial by-product generated from the steelmaking process. Since the slag has produced in the large quantities of over 10 million tons every year including blast furnace slag, electric arc furnace slag, and basic oxygen furnace slag, its effective utilization is major issues in the steel industry (YANG 2015). Some researchers found that the BOF slag can be used as an alternative binder instead of cement and lime when a low strength such as the filling and reclamation materials in the construction field is required (Poh et al. 2006; (Weerakoon et al. 2018). In Japan, the dredged marine clay stabilized with BOF slag has been used as landfill and filling materials or submerged breakwater at the marine environment (Weerakoon et al. 2018). In spite of the use to various fields, there are few studies on the monitoring of the strength development of BOF slag-stabilized marine clay with respect to various curing times immediately after mixing. Non-destructive test is a wide group of analysis techniques, two of those are using the wave and electricity. Several researchers have been using this technique to indirectly predict the engineering properties of construction material such as concrete, soil, stabilized soil (Lee and Santamarina 2005); (Kang et al. 2017a); (Lim et al. 2017).