SAMPAIO,SOFIA1, GOMES, M. GLÓRIA2, BOGAS, J. ALEXANDRE3, ABEL, ANTÓNIO BORGES4

1) MSc Student, Instituto Superior Técnico, DECivil/ICIST, UL, sofiagcsampaio@gmail.com

2) Assistant Professor, Instituto Superior Técnico, DECivil/ICIST, UL, mgloria@civil.ist.utl.pt

3) Assistant Professor, Instituto Superior Técnico, DECivil/ICIST, UL, abogas@civil.ist.utl.pt

4) Assistant Professor, Universidade de Évora, Departamento de Arquitectura, aborgesabel@gmail.com

The concern about a sustainable development and the search for fewer pollutants associated with construction materials had led to the revival of the earth construction. Nowadays, the use of earth in construction must respond to certain characteristics imposed by building regulations. Researches have been carried out to improve the compressed earth blocks (CEB) mechanical properties. However, there are very few publications about the thermal improvement of new CEB solutions, since the thermal behaviour of traditional CEB does not usually meet the building regulations.

Hereupon, this article shows a study of the thermal conductivity of CEBs improved with different insulating aggregate additions. Two different types of earth and three kinds of insulating materials were used in the mixture, namely cork, lightweight expanded clay aggregate and vermiculite. The thermal conductivity of CEB is evaluated for different water contents and at different ages. The incorporation of 1.5% of granulated cork was the most effective, leading to a reduction on the thermal conductivity up to 55-60%, depending on the curing conditions. Nevertheless, for all the envisaged CEB solutions, the thermal conductivity coefficient was lower than 0.65 W/mºC in dried conditions.

Keywords: compressed earth blocks (CEB), thermal conductivity, and insulating materials