## 1 Introduction  
The construction industry today is heavily focused on the use of durable and sustainable construction materials for major infrastructural developments, owing to increased repair and maintenance expenses [1]. The service life of reinforced structures is considered significant when used in aggressive or marine environments. Hence, these structures need to be corrosion proof and durable in terms of structural performance [2]. In traditional construction practices involving the use of cement, a large amount of carbon dioxide emission occurs, and they are also energy intensive. Therefore, it has become necessary to adopt alternate construction materials which are sustainable and durable at the same time. The use of sustainable geopolymer concrete in conjunction with fibre-reinforced polymer (FRP) bars ought to resolve the corrosion issues of traditional reinforced structures [3]. However, in order to achieve wider acceptance for this novel composite structure, it is necessary to investigate the serviceability properties of FRP-reinforced concrete structures, including factors such as deflections and crack widths [1, 3]. The formation of crack width and deflections is often governed by the reinforcement bar spacing and bond behaviour [4, 5]; this necessitates the need for more studies on the bond behaviour of the newly developed composite. Advanced research on using combustion by-products from power plants, including fly ash and slag, as cementitious materials has resulted in the development of self-compacting geopolymer concrete (SCGC), which can be cured under ambient conditions and is very much suitable for structures involving dense reinforcements [6; 7; 8]. The quality of concrete, especially when using self-compacting concretes (SCCs), may be of significance, since the composition of SCCs with higher fines contents and lower amounts of coarse aggregates may affect the shear capacity of the specimens under consideration [9; 10]. It is reported that unlike conventional concrete, self-compacting concrete may cause an accumulation of water when used in reinforced structures, due to bleeding and segregation. Furthermore, research on producing corrosion-resistant materials has resulted in the development of reinforcement bars made of fibre-reinforced polymers, known as fibre-reinforced polymer (FRP) bars. Different FRP bars, such as glass FRP (GFRP), carbon FRP (CFRP), basalt FRP (BFRP), and aramid FRP (AFRP), are now commercially available, and are being used in aggressive environments owing to their superior durability properties in comparison to conventional steel reinforcement [11; 12]. FRP bars are generally produced by pultrusion of the polymer fibre bundles held together by the use of various resins or epoxies [2]. Even though FRP bars are durable, lightweight, and stronger compared to conventional steel reinforcement, the wider application of these bars is limited due to the lack of research on their wider properties, including those relating to bond behaviour--specifically, bonding with concrete and structural performance [13; 14; 15]. Unlike other FRP bars, basalt FRP bars are cost effective and weather resistant in comparison with the widely used glass FRP bars [16]. To promote the wider use of this newer composite construction material, research needs to be conducted on the holistic aspects of structural properties. Current design practices consider the knowledge of bond properties to govern the serviceability and ultimate capacity requirements of reinforced structures [17; 18; 19]. Unlike steel bars, FRP bars are anisotropic, reporting a different pull-out and failure type in comparison with steel bars [20]. It is also to be noted that the bond behaviour of FRP bars in any type of concrete is governed by various factors, including rebar stiffness, rebar surface type, grade of concrete, types of resins used, and volume of fibre bundles in the FRP bars [1; 17]. Knowledge of bond properties is also required for computing the development lengths of the reinforced structures [10; 21].