Analysis of fire resistance of cement mortars with mineral wool from recycling

Resumen

The objective of this research is to analyse the fire resistance of cement mortars with mineral wool from construction and demolition waste (CDW) recycling. The recycled mortars are therefore exposed to direct fire reaching a maximum temperature of 700 °C, and an experimental plan is designed to analyse thermo-mechanical behaviour before and after the testing of the mortars with different types of recycled fibres. The results show that the surface hardness of all mortars is practically unchanged after the fire, whereas the incorporation of fibre residues produce a significant improvement in the flexural strength after fire test compared with the reference mortar. The compressive strength values of all mortars decrease after the fire although they remain at optimum values for use according to regulatory requirements. The values of thermal conductivity are lower or remain unchanged after the fire test. Results show that the addition of these recycled fibres can be a sustainable alternative to the commercial ones currently being used, improving mechanical-thermal behaviour after the fire and preventing the explosive behaviour of the mortars.