Study Of Concretes Properties Based On Pre-saturated Recycled Aggregates

Résumé: The aim of this study was concretes waste recovery by replacing natural aggregates (NA) by recycled aggregates (RA) at rates of 0%, 50% and 100%. Recycled aggregates coming from construction and demolition waste (CDW) present a low quality compared to natural aggregates, the water absorption being their main drawback. Quantities of water absorbed and their variations in times were measured according to the European standard (EN 1097-6). Adding absorbed water during mixing have caused concretes segregations and an excess volume of water was observed at the surface of the concrete. The added water was not totally absorbed by aggregates. The pre-saturation of aggregates 24 hours before mixing and introducing them as a component in concrete was the best method. The initially saturated aggregates did not consume concretes mixture water. Workability by slump test and mechanical strengths developed with pre-saturated aggregates (100 % RA) and (50% RA - 50% NA) were measured on concretes, and then were compared to those of the reference concretes made with 100 % of natural aggregates.

Publié dans la revue: Journal of Materials and Engineering Structures