Use of recycled and secondary aggregates in foamed concretes

Abstract

This paper describes research into improved sustainable construction through the development of foamed concrete incorporating recycled and secondary aggregate fines (RSA). These were selected on the basis of being broadly available and/or significant local production but being otherwise difficult to utilise in structural fill or conventional normal weight concrete. The results indicate that the fine RSA can be successfully used to replace natural sand, either partially or fully. Data presented cover mix design, consistence and strength development. With respect to the results, significant advantage was obtained with the pozzolanic contribution of the conditioned fly ash. In addition, the performance of RSA foamed concretes in terms of drying shrinkage, water permeation, sulfate attack and thermal conductivity values are given. The data show that behaviour is mainly dependent on particle density and given RSA heterogeneity. It is necessary to trial mix unknown materials to enumerate foamed concrete performance.