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La industria de la construcción consume muchos recursos de la naturaleza y genera una gran cantidad de residuos al medio, en todas las fases del ciclo de vida. Por esta razón cada vez se incentiva más el uso de material reciclado, en lugar de materia prima original para la producción de nuevos materiales que contribuyan a cerrar el ciclo de los materiales. El objetivo este estudio consistió en evaluar y comparar los impactos medioambientales de la obtención de árido natural y de árido reciclado. Para el cálculo de los impactos medioambientales se siguió la metodología de Análisis de Ciclo de Vida (ACV) y se escogió como método de evaluación el IMPACT 2002+. Se empleó la base de datos Ecoinvent v2.2, sin embargo, estos datos fueron contrastados y comparados con datos obtenidos de fuentes primarias con el fin de que el inventario de ciclo de vida fuera representativo de España. Los resultados de este estudio muestran que la obtención de árido natural presenta impactos en todas las categorías evaluadas, sin embargo el árido reciclado resulta beneficioso para la mayoría de estas categorías. El árido reciclado proveniente de hormigón armado, presenta impactos en la categoría efectos carcinogénicos y no carcinogénicos, debido al proceso de fundición durante el reciclaje del acero, y ahorros significativos en el resto de categorías estudiadas. Por último, el reciclaje del árido en la obra de construcción resultó en la mayoría de categorías, con ahorros más altos con respecto al reciclaje en planta. The construction industry consumes many natural resources and generates a large amount of waste in the environment, in all phases of the life cycle. For this reason, the use of recycled material is increasingly being encouraged, instead of original raw material for the production of new materials that contribute to closing the materials cycle. The objective of this study was to evaluate and compare the environmental impacts of obtaining natural aggregate and recycled aggregate, taking Spain as a case study. Life cycle assessment (LCA) and the IMPACT 2002+ method were used to calculate the environmental impacts. To carry out the inventory, primary information was obtained and subsequently complemented and compared with the Ecoinvent v2.2 database. The results of this study show that the obtaining of natural aggregate has environmental impacts on all the evaluated categories. Recycled aggregate from reinforced concrete has impacts on the carcinogenic and non-carcinogenic effects category. However, it results in significant savings in the other categories. Recycling aggregate on the construction site resulted in higher savings in most categories than recycling aggregate at the plant.

This paper explains a method developed to assess environmental performance achieved by rehabilitation of residential buildings in Turkey. Several measures focussing on a reduction in the heating demand were investigated such as replacement of window and insulation of different elements of building skin. The influence of several building characteristics was moreover examined such as window to wall ratio (WWR), orientation and building age. Another important aspect which affects environmental performance is climate. In the context of this method, rehabilitations were proposed for temperate-humid climates like Istanbul. According to the assessment results, an environmental performance is obtained for all proposed rehabilitations. When proposed rehabilitations are analysed separately, the environmental performance ratios resulting from the rehabilitations of exterior walls and projected floors, roof, window system, and floors above unheated spaces reduce respectively. WWR has the highest effect on the environmental performance ratios obtained by rehabilitations. The effects of building age and orientation are in negligible amounts when compared to that of WWR. In the future, these assessments should be carried out for different climatic regions of Turkey as well. This method can be used to assess existing and new buildings in terms of environmental impacts by architects, contractors, building owners or municipal authorities. (C) 2013 Elsevier Ltd. All rights reserved.

The impacts of the 30 active substances, most used in Costa Rica (reference year 1998), are evaluated using two models originally developed to support comparative assertions in the context of the life cycle assessment: the multimedia fate, exposure and effect model Impact Assessment of Chemical Toxics 2002 (IMPACT 2002), and the Dynamic Model for Pesticides Residues in Plants. Results show that only five active substances - namely diazinon, mancozeb, chlorothalonil, terbutylazine and ethoprophos - contribute to more than 75% of the aquatic ecotoxicity and yet represent less than 40% of the amount used. More than 90% of the human toxicity is generated by only two active substances - namely terbufos and chlorothalonil - whereas they represent less than 10% of the total amount used. Overall, it would be possible to achieve a 90% reduction of human toxicity and a 75% reduction of aquatic ecotoxicity due to pesticide used in Costa Rica, focusing on only a few active substances. For instance, propiconazole or tridemorph could potentially be replaced by chlorothalonil; ametryn, diuron or paraquat by glyphosate; terbufos by cypermethrin; methyl bromide by metam sodium. (c) 2006 Elsevier B.V. All rights reserved.