Evaluación de la sostenibilidad ambiental de hormigones con áridos reciclados procedentes de residuos de construcción y demolición
- Autores: Elaine Pinto Varela Alberte
- Directores de la Tesis: Marilda Barra (dir. tes.), Enric Vázquez i Ramonich (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2012
- Idioma: español
- Tribunal Calificador de la Tesis: Santiago Gasso Domingo (presid.), Sergio H. Pialarissi Cavalaro (secret.), Fernando Martínez-Abella (voc.), Fernando López Gayarre (voc.), Pedro Serna Ros (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The concrete is one of the most important construction materials. Its sustainability is determined by its durability, its low maintenance and its ability to be reused, recycled or recovered. Hence, the use of recycled aggregates produced from CDW (Construction and Demolition Wastes) can further contribute to the sustainability of the concretes, generating many environmental benefits and allowing the ideal closure of the life cycle of this material. However, the following aspects govern the sustainability of recycled aggregates used in concrete production: the recycled aggregate should be available at short distances, and the recycled concrete produced should not impact the environment and must be as durable as its equivalent conventional option. In Spain, the number of producers of recycled aggregate is high enough to make viable the use of this material. However, the supply of recycled aggregates suitable, according to national legislation, for production of concretes is quite low. The use of mixed recycled aggregates for production of concrete should be better valued since it is a very important step into the consolidations of this recycling sector in the country. Therefore, this study aims to analyze the sustainability of concretes made with recycled aggregates produced in Spain that do not meet the requirements of the current national legislation for concrete production. These investigations were conducted through the evaluation of the durability and the environmental impact, done by the leaching analysis. The evaluation of durability and environmental impact were done by an extensive experimental campaign with concretes produced using different proportions of coarse recycled aggregates (20%, 50% and 100%). Two types of recycled aggregates have been chosen: one mainly comprised of mortar, concrete and unbound aggregates elements, but with a significant amount of asphalt elements (aggregate AH), and another comprised of a large amount of ceramic elements (aggregate AC). Also, concretes made with 100% of conventional aggregate were produced as reference. The properties examined were: porosity, absorption, compressive strength, elastic modulus, drying shrinkage, mercury intrusion porosimetry, capillary absorption, carbonation, chloride penetration, and leaching of both the granular and the monolithic materials. The estimation and evaluation of the sustainability of the recycled concretes produced in this work has been done through indexes and indicators of the forecast lifespan and of the environmental impact created from mathematical models available in the literature and/or experimental results from this study. Finally, a new approach to the sustainable use of recycled concretes is advocated. The results obtained have been analyzed and compared, in order to validate the method developed and to define technical and environmental quality levels for recycled aggregates used in concretes in accordance with the needs, limitations and strengths of each situation.
