Prototype of alveolar gypsum blocks with plastic waste addition for partition walls: Physico-mechanical, water-resistance and life cycle assessment

The development of eco-friendlier building products incorporating waste as an alternative to raw materials has become increasingly relevant within the construction industry. With this in mind, this study presents a prototype of an alveolar gypsum block for partition walls, wherein partial replacement of the binder (i.e. gypsum or cement) was made using two types of plastic waste (i.e. polypropylene- and nylon-based). Two plastic waste-containing composites, with contents considered as optimum in previous studies (AGB/PP/7.5–7.5 wt% polypropylene content; AGB/PA6/2.5–2.5 wt% nylon content), were produced and extensively analysed in comparison to a reference block. Physico-mechanical (bulk density, surface hardness, flexural and compressive strength), water permeability and thermal properties were evaluated and compared to commercially available counterparts. In addition, the prototypes’ environmental impact was determined by conducting a simplified life cycle assessment primarily based on the “Global Warming Potential” and “Embodied Energy” categories. The results showed a widespread improvement in the mechanical performance of plastic-containing blocks and more so for those reinforced with nylon fibres when compared to the reference product. Furthermore, notable reductions in thermal conductivity and water permeability were observed on the blocks due to the addition of plastic waste. Both types of blocks presented a slight environmental impact decrease because of the reduction of raw materials (i.e. gypsum). These findings are encouraging from a practical application point of view and may create a notable opportunity for replacing more frequently gypsum with polypropylene- or nylon-based wastes for alveolar blocks for building partition walls.