Upgrading of demolition concrete into new construction concrete

Abstract

In Morocco, buildings, road and urban infrastructure are ageing relatively quickly and often require renovation or demolition work. The large amount of demolition rebus generated is a considerable challenge that will have to be buried or reused. The reuse of these materials is an important aspect of their management, especially as regulations concerning landfill sites are becoming increasingly restrictive. Another challenge facing the construction industry is the reduction of natural aggregate sources due to the high demand for raw materials. The use of demolition concrete as recycled aggregates in new concrete is a promising solution in the current context of sustainable development. However, it should be noted that the properties of recycled aggregate concrete are different from those with natural aggregates, mainly their porosity, density and resistance. These differences are attributed to the cement mortar that adheres to natural aggregate particles, constituting an aggregate in itself.This work aims to study the influence of using a combination of Fine Recycled Aggregates (FRA) and Coarse Recycled Aggregates (CRA), with Natural Aggregates (NA). Since the use of the recycled coarse fraction in the production of new concrete may have revealed good performance in recycled concrete, the use of the recycled fine fraction remains still very limited, due to its absorptive capacity by reference to previous bibliographic studies. In order to improve the quality of Recycled Concrete (RC), this work also seeks to study a new crushing alternative that favours less adhered mortar.