Preliminary investigations on the development of a lightweight mortar using recycled phenolic foam

Phenolic foam (PF) is widely used across the globe as an insulation material in buildings. However, manufacturing PF panels generates large quantities of waste that are either landfilled or incinerated. This research explores a solution to this problem by investigating the feasibility of using recycled PF waste from insulation panel manufacturing to produce a sustainable and lightweight mortar that features energy-efficient and fire-retardant properties. In this context, PF off-cuts from an industrial site were collected and chemically categorised to determine their composition. Subsequently, the PF material was granulated and utilised as a sand substitute in the development of cement-based mortar. Sand replacement ratios of 0%, 20% and 40% by volume were employed. The physical, mechanical, and thermal properties of the novel PF-mortar material were examined by assessing the bulk density, compressive strength and thermal conductivity. It was found that incorporation of PF waste reduced the density of mortar by an average of 10% per 20% of sand replacement, and that the compressive strength decreased by an average of 28% at 20% of sand replacement, and 51% at 40% substitution rate. This research supports the development of a circular economy and sustainable building practices in the construction industry.