Enhancing the environmental sustainability of human activities and industrial processes is a common challenge in various branches of the modern research and technology. The construction sector is fully concerned by this challenge. Particularly, since concrete is the most widely employed construction material, several solutions are nowadays under investigation to reduce the environmental impact of its production. They mainly consist of partially replacing "natural" constituents with recycled ones, in view of the twofold objective of reducing both the demand of raw materials and the amount of waste to be disposed in landfills. However, the definition of stable correlations between the actual properties of concrete produced with the aforementioned recycled constituents is still considered as an open issue. This paper is intended as a contribution to such an issue and reports the main results of a wide experimental campaign recently carried out (and partially still ongoing) at the Laboratory of Materials testing and Structures (LMS) of the University of Salerno (Italy) in which the mechanical and physical properties of recycled aggregate concrete (RAC) made with aggregates obtained by crushing some concrete structural elements, are investigated. The influence of the initial moisture condition of natural and recycled coarse aggregates on the properties of fresh and hardened concretes is analysed. Concrete mixes were prepared with natural and recycled aggregates at different proportions (i.e. 0%, 30% and 60%), controlling the initial moisture states of the aggregates at 24h oven-dried (OD) and saturated surface-dried (SSD) condition and keeping the water to cement ratio equal to 0.50. At the fresh state, the slump loss for the various concrete mixtures was determined, while the compressive strength tests have been performed after water curing of 3, 7 and 28 days. The activities presented in this study are framed in the EU-funded project, EnCoRe (www.encore-fp7.unisa.it).
The influence of the initial moisture conditions of coarse aggregates on the properties of RAC
FAELLA, Ciro;CAGGIANO, ANTONIO;LIMA, CARMINE;MARTINELLI, Enzo;PEPE, MARCO;REALFONZO, ROBERTO
2013-01-01
Abstract
Enhancing the environmental sustainability of human activities and industrial processes is a common challenge in various branches of the modern research and technology. The construction sector is fully concerned by this challenge. Particularly, since concrete is the most widely employed construction material, several solutions are nowadays under investigation to reduce the environmental impact of its production. They mainly consist of partially replacing "natural" constituents with recycled ones, in view of the twofold objective of reducing both the demand of raw materials and the amount of waste to be disposed in landfills. However, the definition of stable correlations between the actual properties of concrete produced with the aforementioned recycled constituents is still considered as an open issue. This paper is intended as a contribution to such an issue and reports the main results of a wide experimental campaign recently carried out (and partially still ongoing) at the Laboratory of Materials testing and Structures (LMS) of the University of Salerno (Italy) in which the mechanical and physical properties of recycled aggregate concrete (RAC) made with aggregates obtained by crushing some concrete structural elements, are investigated. The influence of the initial moisture condition of natural and recycled coarse aggregates on the properties of fresh and hardened concretes is analysed. Concrete mixes were prepared with natural and recycled aggregates at different proportions (i.e. 0%, 30% and 60%), controlling the initial moisture states of the aggregates at 24h oven-dried (OD) and saturated surface-dried (SSD) condition and keeping the water to cement ratio equal to 0.50. At the fresh state, the slump loss for the various concrete mixtures was determined, while the compressive strength tests have been performed after water curing of 3, 7 and 28 days. The activities presented in this study are framed in the EU-funded project, EnCoRe (www.encore-fp7.unisa.it).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
