Thermal performance of concrete with recycled aggregates from CDW plants

Abstract

This investigation intends to analyse the thermal performance of concrete with recycled aggregates (RA) from construction and demolition waste (CDW) collected from several locations in Portugal. A total of 17 concrete mixes were analysed by means of thermal conductivity tests. Firstly, the composition and characteristics of the aggregates (natural and recycled) used in the production of the concrete mixes were analysed thoroughly, by means of several physical and chemical tests. Later, in order to evaluate the thermal behaviour of the mixes, several tests were performed and their results analysed, both on the fresh-state (slump with the Abrams cone test, density and air content) and the hardened state (compressive strength and thermal conductivity). The analysis of the thermal behaviour showed that the use of RA improves the thermal performance of the concrete mixes. The extent of this change was shown to be quite variable depending on the origin of the RA used.