Eco-friendly vs Fire Safe? Conceptualising Fire Risk for Construction Systems Incorporating Waste and Biomass

There is an international push to incorporate materials such as waste plastic, rubber and biomass, amongst other products, into construction systems to enhance sustainability and reuse waste. This paper investigates the fire risk associated with incorporating (a) continuous-, (b) macro- (large, distinct fuel packages), and (c) micro-encapsulated (small, dispersed pieces) combustible materials, along with (d) biomass into construction systems. Heat release rates, fire growth rates, smoke production, fire resistance ratings, firefighting requirements and general building safety can be influenced when these materials are used. Fire risk cannot be ignored and may be one of the biggest barriers to various sustainable construction systems. A challenge to be overcome is to define what level of smoke and energy release is considered safe. Many of the systems will readily obtain a standard fire resistance rating and pass reaction-to-fire tests, meaning that they are permitted according to building codes. Of the systems considered, plastered masonry systems with micro-encapsulation are likely to present a low fire risk, with continuously-encapsulated waste plastic systems presenting a high fire risk. Outer plaster layers, which function as passive protection, are often essential in protecting combustible internal materials.