Title: A Physically-Based Conceptual Approach For Designing RAC Mixtures

Author(s): Marco Pepe; Romildo Dias Toledo Filho; Eduardus Koenders and Enzo Martinelli

Publication: Symposium Paper

Volume: 305

Issue:

Appears on pages(s): 44.1-44.10

Keywords: Attached Mortar; Compressive strength; Hydration; Mixture proportions, Porosity; Recycled Aggregate Concrete; Recycled Concrete Aggregate; Sustainable concrete

DOI: 10.14359/51688608

Date: 9/1/2015

Abstract:
With the adoption of a policy encouraging the use of recycled aggregates in concrete production, the EU is pursuing the twofold objective of reducing both the demand of natural resources and the environmental impact of the construction industry, that is characterized, as it is well-known, by a significant demand for both energy and raw materials. Therefore, recycling is the main action that can be implemented for turning waste into eco-friendly materials and constituents of newly produced concrete. Particularly, waste concrete can be processed and reused as coarse aggregate, leading to particular kinds of “green concretes” often referred to as Recycled Aggregates Concretes (RACs), in which ordinary coarse aggregates are partially or totally replaced by Recycled Concrete Aggregates (RCAs), while at the same time reducing the so-called Construction and Demolition Waste. However, no well-established theoretical models are capable nowadays of predicting the relevant properties of RACs depending on the actual mixture composition. This paper summarizes the key aspects of a novel physically-based conceptual approach aimed at “designing” RAC mixtures. The formulations proposed in this study are based upon the results achieved from several experimental and numerical investigations carried out for various types of RCAs.