Fire and High Temperature Behaviour of Thermal Mortars

Maria João Sobral Cordeiro Pupo Correia

Key information

Authors:

Maria João Sobral Cordeiro Pupo Correia (Maria João Sobral Cordeiro Pupo Correia)

Supervisors:

Inês Dos Santos Flores Barbosa Colen (Inês Flores-Colen); João Pedro Lage da Costa Firmo (João Pedro Lage da Costa Firmo)

Published in

07/01/2022

Abstract

The EU has committed to reach net-zero CO2 emissions by 2050. The decarbonization pathways included the implementation of regulations and standards that have driven the use of new building envelope systems made of composite materials with insulating properties to fulfil energy performance requirements. Following this approach, the use of aerogel-based mortars has begun to be explored due to its improved thermal insulation properties and potential good high temperature and fire behaviour. In this context, the present work aims at characterizing the fire and post-fire behaviours of an innovative thermal mortar with aerogel incorporation, including the comparison with one conventional solution, a thermal mortar with expanded polystyrene granules (EPS), and using a lime-based mortar, as reference. To this end, an extensive experimental campaign was developed, including (i) mechanical characterization tests; (ii) thermophysical ones; (iii) microstructural analyses; (iv) fire reaction tests; and (v) fire exposure tests whose results were used to determine/ calibrate thermal conductivity and specific heat at elevated temperatures. Within these procedures it was possible to compare the fire and high temperature behaviour of thermal mortars as well as suggest complementary parameters (beyond the standards) to evaluate their performance under these conditions. The results showed that both thermal mortars are thermally unstable due to the susceptibility of polymeric constituents when subjected to high temperatures. Despite the referred instability, the aerogel-based mortar exhibited higher residual properties, proving that its constituents (in particular, aerogel) are less degraded by exposure to high temperatures.