## 2 Materials and Methods
### Infill Material for Composite Floor Slabs  
The self-compacting geopolymer concrete (SCGC) recently developed by the engineering team at Deakin University Deakin (2018) was used as the primary infill material in this study. Due to the corrugated nature of test slabs, a flowable type of concrete allows better placement without the use of vibrators. The SCGC infill is self-compacting and flowable in nature, which facilitated the casting and placing of the infill into the slab specimens without any additional equipment requirements for compaction. Figure 3 shows the pouring of infill SCGC and casting of composite floor slabs.  
Figure 1: Overall dimensions of panel: (**a**) top view of the panel; (**b**) cross-section A-A; (**c**) cross-section B-B; (**d**) sample panels with a slot along the bents.  
SCGC used in this study is a zero-cement, flowable mix made from industrial combustion waste products, including fly ash, micro-fly ash and slag. The geopolymer concrete mix attains its cementitious properties and a design compressive strength of 40 MPa at 28 days of ambient curing by adding sodium metasilicate. The binder materials, alkali activator (anhydrous sodium metasilicate), and the aggregates (coarse gravel and fine sand) were sourced from local suppliers in Australia. Furthermore, another infill material that contained the original self-compacting geopolymer mix added with chopped basalt fibres (1% by weight of the total binders in the SCGC mix) was also used in this study. The details of the model are given in Table 1.  
Figure 3: Casting of panels.  
Figure 2: Specim types.  
of the SCGC mix and the amount of chopped basalt fibres used as the infill material are given in Table 1[29]:  
The addition of short fibres is proven to reduce the shrinkage cracks in the infill slab [30]. The addition of chopped basalt fibres of 12 mm length reduces the early cracks in self-compacting concrete mixes, which enhances the performance of the test specimens [31].  
Furthermore, the floor panels are reinforced with non-corrosive Basalt FRP (BFRP) bars to provide the required flexural strength and satisfy the design requirements. These BFRP bars and the basalt fibres were sourced from Beyond Materials, Australia [32]. All the composite slab specimens were reinforced with BFRP bars of 8 mm diameter at 100 mm spacing as per the ACI 440.1R-15 design requirements [33]. The combination of self-compacting geopolymer concrete with BFRP reinforcing bars is a sustainable, environmentally friendly, and durable alternative against the conventional steel-concrete reinforced structures. The use of BFRP bars replacing the traditional steel reinforcing bars will help to reduce the overall weight of the test specimen and provide protection against corrosion in addition to the higher tensile strengths.  
The total number of test specimens and the type of infill adopted for this experimental testing program is detailed in Table 2. The influence and nature of the performance of chopped basalt fibre containing infill slabs are confirmed by single- and double-cell panels. Hence, the experiment was optimised without including chopped basalt fibres in the triple-cell configuration.