Influence of granite powder on the mechanical behavior of recycled aggregate (gravel) concrete

Aggregates are granular materials used in construction, either bound with substances such as binders and bitumen to produce concrete, road concrete, etc., or unbound as in railway ballast or drainage systems. Old buildings are often demolished to make way for new ones. Demolition waste can be recycled into reusable aggregates for concrete production. Studies have shown that concretes produced with such aggregates require more water and exhibit a compressive strength reduced by 5 to 40% compared to concretes made with natural aggregates. To improve the properties of these materials, granite powder was added to the sand–recycled aggregate–cement mixture. Thus, 5%, 7%, 10%, 12%, and 15% granite powder were incorporated into recycled aggregate concretes, and 10% into natural aggregate concrete, then subjected to compression and sclerometer tests. The aim of this study is to investigate the influence of granite powder on the mechanical behavior of recycled aggregate concrete. The results obtained show that the compressive strength of recycled aggregate concretes remains lower than that of natural aggregate concretes. However, the addition of granite powder improves the strength of both natural and recycled concretes.