Effects of accelerated ageing on the long-term thermal conductivity of thermal insulating mortars

Abstract

Thermal insulating mortars have been widely used in building facades, thus improving the thermal performance of the building envelope. However, reliable data on their long-term thermal performance is still lacking. The aim of this work is to evaluate the long-term thermal conductivity of industrially produced and experimentally designed thermal mortars with EPS, cork and silica aerogel aggregates. The long-term performance of the mortars was assessed prior, during and after exposure to three accelerated ageing tests including elevated temperature, freeze-thaw and high humidity levels. For each test, an empirical model was used to compute the acceleration factor, correlating accelerated and natural ageing. The results show that a maximum increase of thermal conductivity up to 30% can be obtained after ageing.