Environmental life cycle assessment of concrete made with fine recycled concrete aggregates L. Evangelista Instituto Superior de Engenharia de Lisboa, Lisboa, Portugal J. de Brito Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa, Portugal ABSTRACT: The majority of worldwide structures use concrete as its main material. This hap- pens because concrete is economically feasible, due to its undemanding production technology and ease of use. However, it is widely recognized that concrete production has a strong environmental impact in the planet. Natural aggregates use is one of the most important problems of concrete produc- tion nowadays, since they are obtained from limited, and in some countries scarce, resources. In Portugal, although there are enough stone quarries to cover coarse aggregates needs for several more years, supplies of fine aggregates are becoming scarcer, especially in the northern part of the country. On the other hand, as concrete structures’ life cycle comes to an end, an urgent need emerges to establish technically and economically viable solutions for demolition debris, other than for use as road base and quarry fill. This paper presents a partial life cycle assessment (LCA) of concrete made with fine recycled concrete aggregates performed with EcoConcrete tool. EcoConcrete is a tailor-made, interac- tive, learning and communications tool promoted by the Joint Project Group (JPG) on the LCA of concrete, to qualify and quantify the overall environment impact of concrete products. It con- sists of an interactive Excel-spreadsheet in which several environmental inputs (material quanti- ties, distances from origin to production site, production processes) and outputs (material, en- ergy, emissions to air, water, soil or waste) are collected in a life cycle inventory, and are then processed to determine the environmental impact (assessment) of the analysed concrete, in terms of ozone layer depletion, smog or “greenhouse” effect. 1 INTRODUCTION The construction industry is known as being environmentally inefficient. The intensive extrac- tion of raw materials for the production of materials involved in buildings execution, the energy needed to perform heavy industrial processes and the resulting debris, both from new construc- tion and demolition of old one, all contribute to a strong penalization of the environment. One of the materials most used in the construction of structures is concrete because of its ease of production, low-demand technologies and easy-to-obtain materials needed in its production, leading to low production costs. However, in order to produce concrete it is necessary to extract stone both for cement produc- tion and to be used as aggregates. Usually, concrete fine aggregates are obtained from the ex- traction of sand from river beds or maritime coats. However, this activity brings along severe environmental problems: the alteration of the water flow in rivers or of the tides in seas leads to the erosion of the margins, with direct consequences on the nearby infrastructures. Even though in Portugal and particularly in the south of the country there are relevant am- ounts of natural sand for extraction, some recent studies (Dias, 2005) point out the need to im-