Incorporation of the polyurethane pellet waste for the improvement of the thermal insulation of non-structural concrete blocks

Abstract

The lapilli is an aggregate commonly used for the manufacturing

of commercial concrete blocks in the Canary Islands. These

blocks are manly utilized for exterior walls of buildings. However,

these blocks have two main weaknesses. The first is associated

with the fact that the concrete mixes, containing only lapilli as

an aggregate, have a high thermal conductivity and therefore,

subsequent blocks do not perform well as insulation. The second

important weakness is that the extraction of this lapilli aggregate

causes an enormous landscaped deterioration and environment

damage. This research presents the results of an experimental

study concerning the improvement of the thermal insulation

of the Canarian concrete blocks through the incorporation

of polyurethane pellets from waste electrical and electronic

equipment. Results show that the inclusion of the pellet waste

enhances the thermal behaviour of the concrete between 38%

and 64%, compared to concretes containing only lapilli as an

aggregate. Furthermore, the inclusion of polyurethane pellet

waste provides a recovery procedure of this residue. A concrete

block prototype was manufactured using polyurethane pellet

waste as an example of a possible building material with a minor

environmental impact and an obvious economic saving in raw

materials.