## 1 Introduction  
Ground granulated blast-furnace slag (GGBS) is an industrial byproduct that is widely used as a substitute for ordinary Portland cement (OPC), and several extant studies focused on the same [1]. Specifically, GGBS are mainly used as supplementary cementitious materials (SCMs) and alkali-activated materials (AAMs). When GGBS is used as a SCM, it improves durability, long-term strength, and constructability [2; 3]. Given the high demand for natural resources to satisfy demands for infrastructure, there are significant opportunities to apply SCMs in the construction of carbon-saving infrastructure [4; 5]. Furthermore, studies on AAMs have attracted considerable attention in the construction industry over the last few decades because it provides effective alternatives to OPC [6; 7]. However, AAMs are not actually applied to the field due to high cost, short initial setting time, and high shrinkage. Therefore, in-depth research on SCMs is necessary to improve field applicability. Specifically, GGBS is a byproduct that is generated during the production of pig iron. It becomes fine, granular, and amorphous after quenching and crushing. Additionally, GGBS is mainly composed of four chemical elements, namely SiO\({}_{2}\), Al\({}_{2}\)O\({}_{3}\), CaO, and MgO. Thus, GGBS can be referred to as aluminosilicate with CaO and MgO as base chemical elements [8; 9]. Furthermore, GGBS exhibits a hydration reaction when it is in contact with water, sulfate, or alkali starter, etc. The reaction rate increases when the pH value increases [3; 10]. For example, when GGBS is placed in a saturated aqueous solution of calcium hydroxide (Ca(OH)\({}_{2}\)) corresponding to or exceeding pH 12, hydration begins when the chain structure of aluminosilicate is cut. Nevertheless, the reaction stops when the supply of Ca(OH)\({}_{2}\) is interrupted and the amount of alkali decreases below a certain concentration or the reaction products shielding effect [11]. Additionally, impermeable acid film is generated on the particle surface when GGBS is in contact with water. In this case, the reaction can be resumed when the film is destroyed by the strong alkali stimulation of NaOH, KOH, and Ca(OH)\({}_{2}\) + CaSO\({}_{4}\). Hardening begins when insoluble matter precipitates in the solution following the occurrence of the dissolution reaction on the GGBS surface via the aforementioned type of stimulation [12]. Furthermore, the durability of concrete composed of OPC 100% can be improved by adding GGBS as SCMs [13]. The durability of concrete mixed with GGBS is improved by the latent hydraulic reaction that occurs during the hydration process of the cement [14; 15]. Calcium hydroxide (CH) and calcium silicate hydrate (C-S-H) gels are formed during the better hydration of Portland clinker. Moreover, CH is the most soluble hydration product and becomes a fragile linkage by cement. When concrete is in contact with water, porosity increases due to the dissolution of CH, and concrete becomes more sensitive for further leaching and chemical intrusion [16]. Subsequently, the GGBS added to concrete reinforces and fills pores and improves durability to prevent the intrusion of water and other chemicals [17; 18]. [PERSON] [19] reported that finer GGBS (specific surface area: 5000 cm\({}^{2}\)/g or 6000 cm\({}^{2}\)/g) increased the fracture toughness of concrete. [PERSON] [20] inferred that the compressive strength of ultrahigh performance concrete (UHPC) with a high volume fraction of GGBS improved when the replacement ratio ranged from 40% to 60% based on the temperature condition. It was also verified that UHPC with a higher volume fraction of GGBS exhibited denser microstructure by analyzing the microstructure characteristics by using a scanning electron microscope (SEM). Additionally, [PERSON] [21] suggested the economic ratio of ternary blended concrete for securing strength at 28 d of age as corresponding to silica:GGBS:OPC = 10:30:60.