Structural Performance of Modular Sandwich Composite Floor Slabs Containing Basalt FRP-Reinforced Self-Compacting Geopolymer Concrete

A newly developed innovative steel–geopolymer concrete composite floor slab for use in modular construction is investigated in this study. We present experimental results on the flexural behaviour of eight modular sandwich composite floor slabs with different configurations containing self-compacting geopolymer concrete (SCGC) as infill and Basalt FRP (BFRP) bars as reinforcement. The use of sustainable infill material such as SCGC and non-corrosive BFRP in the proposed composite floor slabs is beneficial from the perspective of environmental sustainability. This study also compares the performance of these composite floor slabs against their hollow counterparts. The overlap between the cells in multi-cell panels acts as additional partitioning walls. The infill material offers the sandwich composite floor slabs significant advantages by improving their load-carrying capacity. A critical analysis of the composite floor slabs for load displacement, failure modes, and strain behaviour is also conducted. The study concludes that the sandwich panels with multiple smaller cells and infill materials exhibit a sound structural performance, reporting a 6–8 times higher load-carrying capacity than their hollow counterparts. A comparison of hollow and infilled panels shows that the infill sandwich panels are suitable as structural slabs. At the same time, the former is more suitable for temporary formworks, shelter, and pedestrian platform applications.