Análise do custo do ciclo de vida de concretos ecoamigáveis com agregado residual de demolição e pozolana

Abstract

The civil construction stands out as a sector with a high environment impact. In this industry, concrete is the main protagonist due to the large volume and the demand of a non-renewable natural resources for its production. Therefore, this work aims to study the sustainability and the costs of different alternatives of eco-friendly concrete, composed by two types of cement (CP IV and CP V-ARI), rice husk ash pozzolan (RHA) and different rates of construction and demolition waste (CDW) . Tests of axial compression stress and accelerated carbonation were performed in order to enable the modular life cycle evaluation and the costs estimation. The results allowed an integrated comparative analysis of different concrete mixtures in terms of environmental, economic and structural performance. The presence of CDW in mixtures with CP IV was not beneficial, as it considerably reduced the service life of the samples. When performing the unitary assessment of costs and environmental impacts, the mixture with the highest concentration of RCD (30%) and CP IV cement showed the worst performance. The replacement of cement by RHA was positive only in mixtures with low CDW content (15%) . Finally, the alternative which present the best sustainability x cost integration was the one containing 15% CDW, cement CP V-ARI and no pozzolanic addition.