## 1 Introduction  
In order to increase the ratio of strength to weight of the structures and increase energy absorption, in recent years, the combination of concrete with steel faceplates has been considered by researchers. In this combination, a concrete piece can be mounted on a steel faceplate using a sufficient number of shear connectors [1], or a concrete core can be sandwiched between two steel faceplates, which is known as a steel-concrete-steel (SCS) sandwich. SCS sandwich slabs are made of a concrete core between two steel faceplates connected using adhesive materials or mechanical shear connectors [2, 3]. SCS sandwich slabs show better performance in terms of stiffness, strength, and against fire and impact compared to the reinforced concrete slabs manufactured with normal concrete. Using the SCS structure reduces the number of stiffeners and welding processes, for example, in ship-hull. The main advantages of SCS include: (1) the steel faceplates play an important role to increase the flexural behaviour and construction efficiency,(2) the steel plates increase the impact resistance of concrete slab, and (3) also these can act as an impermeable layer, especially for gas and liquid vessels. According to the previous researches, SCSs have excellent structural performance in terms of static, impact, and blast strength [4; 5; 6; 7]. SCSs can be used in different projects, including submerged tube tunnels, building core walls, offshore structures, bridge decks, etc. [8; 9; 10; 11]. In many studies, the SCS has been used to manufacture offshore structural walls for increasing resistance against contact with water floating ice pressures [12; 13]. Extensive works have also been done by researchers to investigate the potential use of this system is lightweight deck structures and for the strengthening of weakened areas in ship structures [14; 15]. To improve the composite behaviour of the SCS system, different mechanical shear connectors are developed in two ways of one end welded and two ends welded. The common one end welded shear connectors are C-shaped connectors, as shown in Figure 1a [16], L-shaped connectors, as shown in Figure 1b [3], and overlapped headed studs in a double-skin composite structure (DSC) as illustrated in Figure 1c [17]. One of the drawbacks of these shear connectors used for SCS sandwich construction is their relatively poor performance under high shear force. Additionally, friction welding connectors in Bi-steel structure [18] and J-hook connectors [19; 20; 21; 22] are the common two end welded shear connectors, as demonstrated in Figure 1d,e, respectively. Bi-steel connectors are the best in comparison to other shear connectors in terms of performance but with two serious practical problems including, (1) Need for advanced friction welding equipment, and (2) Minimum height at least 200 mm for friction welding. The SCS construction with J-hook shear connectors does not have Bi-steel problems due to interlocking J-hook connectors after preparing each faceplate with one end welded shear connectors. However, precisely adjust the hooks against each other, and straightening hooks under loading can be the drawbacks of the J-hook connectors. There is limited literature on the development of corrugated-strip connectors (CSC) (Figure 1f) that were first proposed by [PERSON] et al. in 2010 [2; 23]. One of the advantages of this system compared to other shear connectors is that unlike previous models in which shear connectors are normal to steel face plates, the angle of shear connectors can be aligned perpendicular to the diagonal crack line of concrete approximately. In this system, shear connectors are welded to steel face plates from both sides that create thickness limitation in practice and need modern welding equipment to connect both sides of connectors to both steel face plates similar to Bi-steel system. Practical restrictions can be the main reason for the non-development of these shear connectors.