This study proposes a conceptual formulation for predicting and controlling the key mechanical properties of structural concrete produced with coarse Recycled Concrete Aggregates (RCAs). As a matter of principle, due to the presence of attached mortar, RCAs are significantly more porous than corresponding natural aggregates, and, consequently, affects the mixture proportioning rules commonly adopted for ordinary concretes. In general, common rules cannot be applied for cement-based mixtures produced with RCAs to create Recycled Aggregate Concrete (RAC). Therefore, the approach proposed herein is intended at generalizing the aforementioned rules by explicitly taking into account the specific features of RCAs. The proposed methodology is supported by a wide set of experimental results which unveil the influence of several aspects and parameters, such as source and processing procedures of RCAs, aggregate replacement ratio, water-to-cement ratio, water absorption capacity and initial moisture condition of aggregates, on the resulting performance of RAC. The proposed methodology demonstrates that the mechanical behavior of RAC can be easily predicted by considering only one unique parameter, i.e., the water absorption capacity, to identifying the “quality” of RCAs, and with this, the quality of the produced RAC.
Mix Proportioning for Structural Concrete Containing Recycled Concrete Aggregates
PEPE, MARCO;MARTINELLI, Enzo
2017-01-01
Abstract
This study proposes a conceptual formulation for predicting and controlling the key mechanical properties of structural concrete produced with coarse Recycled Concrete Aggregates (RCAs). As a matter of principle, due to the presence of attached mortar, RCAs are significantly more porous than corresponding natural aggregates, and, consequently, affects the mixture proportioning rules commonly adopted for ordinary concretes. In general, common rules cannot be applied for cement-based mixtures produced with RCAs to create Recycled Aggregate Concrete (RAC). Therefore, the approach proposed herein is intended at generalizing the aforementioned rules by explicitly taking into account the specific features of RCAs. The proposed methodology is supported by a wide set of experimental results which unveil the influence of several aspects and parameters, such as source and processing procedures of RCAs, aggregate replacement ratio, water-to-cement ratio, water absorption capacity and initial moisture condition of aggregates, on the resulting performance of RAC. The proposed methodology demonstrates that the mechanical behavior of RAC can be easily predicted by considering only one unique parameter, i.e., the water absorption capacity, to identifying the “quality” of RCAs, and with this, the quality of the produced RAC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.