Issues in the Use of Aggregates from Demolition Sites, in Construction, with a View to Protecting the Environment

Abstract

Construction professionals are increasingly confronted with issues related to the preservation of the environment. For several years, they have been facing a double problem. In highly urbanized regions, the number of buildings is increasing, and with them the need for raw materials. Concrete is one of the most used materials in modern works, the need for aggregates, one of its components is very high. However, the quarries of aggregates are running out. Potentially usable spaces are becoming scarce, and construction professionals are facing supply difficulties. On the other hand, in the building sector, millions of tons of waste from demolitions are still too often deposited in storage facilities. It is becoming clear that the recovery of this waste is a major environmental issue, and that their reuse in the form of aggregates would be a beneficial alternative for the environment. It would allow pollution by landfill to be limited. In order to determine a relevant use of recycled aggregates in construction, we have done the tests for determining the density, los angeles, water absorption, proctor test on its aggregates. We got the following conclusions: recycled concrete aggregates are generally more absorbent and less dense than ordinary aggregates. The form of recycled aggregates is similar to that of crushed stone. The concretes made with these aggregates have acceptable workability.  Due to their composition, these recycled aggregates have different characteristics from natural aggregates, and their mechanical behavior is distinct. Indeed, recycled aggregates are more porous, have a higher water absorption coefficient, contain hydrates, and have interfacial transition zones, which are weak zones for the mechanical strength of the concrete. Recycled aggregates are also suitable for road foundation work.