## 1 Introduction  
The global cement and concrete industry is facing environmental challenges. First, the calcination process for cement clinkers releases 0.8-1.0 tons of carbon dioxide to produce one ton of ordinary portland cement (OPC) [1; 2]. As a result, the total CO\({}_{2}\) emission from worldwide OPC production is equivalent to 6-8% of global CO\({}_{2}\) emissions [3]. Furthermore, the production of OPC concrete consumes a significant quantity of fresh water, more specifically one billion tons of fresh water per year [4]. Currently, water shortages are already serious problems in the Middle Eastern and North African nations, which have already imported a huge volume of fresh water, such as Saudi Arabia, United Arab Emirates, Bahrain, Qatar, Kuwait, Yemen, Libya, Jordan, and Israel [5]. This water shortage may become a vital challenge to other nations in the near future due to climate change [6]. Finally, existing concrete structures suffer durability issues due to chemical deteriorations, such as chloride attacks, corrosion, and sulfate attacks [2; 7]. Therefore, the enhancement of concrete durability will help to improve environmental sustainability by reducing unnecessary resource consumption for maintenance. New eco-efficient binders, such as calcium sulfoaluminate cements [8], super-sulfate cements [9], calcium aluminate cements [10], and alkali-activated binders [11; 12], have been introduced and developed to address the significant CO\({}_{2}\) emissions from OPC production. The alkali-activated binder is likely to be a high-profile candidate to replace OPC due to its significantly low production of CO\({}_{2}\) and comparable performances of strength and durability to OPC [13]. To reduce the current level of fresh water consumption for OPC concrete production, many earlier studies have explored the possible use of seawater in the concrete's production [14; 15]. However, the presence of chloride from seawater in concrete likely induces serious corrosion of embedded steel bars [2]. In the previous literature, alkali-activated binders showed better durability against a saline environment compared to OPC pastes [16]. Thus, in unavoidable situations leading to the use of seawater, the application of alkali-activated binders would be a better choice than OPC in terms of chloride-induced durability problems. In addition to using seawater, for concrete structures exposed to marine environments, alkali-activated binders could also provide a longer service life of concrete structures with better durability against seawater [17]. Consequently, alkali-activated binders may play important roles in addressing the aforementioned environmental concerns (i.e., CO\({}_{2}\) emissions, water shortages, and durability). Therefore, it is important to understand the interactions between seawater and alkali-activated binders. Among the alkali-activated binders, two representatives are alkali-activated fly ash (also called fly ash-based geopolymer) and alkali-activated slag. In the previous literature, [PERSON] et al. well-reviewed the recent research on the chloride resistance of alkali-activated fly ash/slag systems [18], and showed that most studies on the chloride resistance of alkali-activated binders were based on measurements of rapid chloride permeability tests (RCPT) and non-steady-state migration (NSSM). Few studies have been conducted on Cl-bearing phases, which are capable of binding and immobilizing chloride, and stable phases when seawater is used as the mixing water in alkali-activated binders, while [PERSON]'s salt and [PERSON]'s salt in OPC pastes have been studied actively [19; 20]. Regarding the stable phases in alkali-activated fly ash with seawater, [PERSON] et al. attempted to synthesize zeolite from alkali-activated fly ash using seawater at various temperatures, and they found zeolite X, zeolite ZK-5, and sodalite in the samples [21]. Regarding Cl-bearing phases in alkali-activated slag, [PERSON] et al.